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Sample records for abri peptide 1-23

  1. Simultaneous Detection of Flavonoids, Phenolic Acids and Alkaloids in Abri Herba and Abri Mollis Herba using Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    Yan, Wenying; Han, Qingjie; Guo, Panpan; Wang, Chunying; Zhang, Zijian

    2016-01-01

    Abri Herba has remarkable properties, such as cleanup heat detoxification, dampness and activating blood circulation to dissipate blood stasis; as a result, it has been applied to treat acute or chronic hepatitis and mastitis. Abri mollis Herba is often used as Abri Herba. Hierarchical cluster analysis (HCA) was applied to compare the similarities and differences of the chemical compositions in the two types of medicinal materials. To establish a high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) method for the simultaneous analysis of 15 flavonoids, two phenolic acids and three alkaloids in Abri Herba and Abri mollis Herba. The chromatographic separation was performed on a C18 column with a mobile phase of methanol (A), acetonitrile (B) and 0.5‰ acetic acid in water (C) using gradient elution. The detection of the target compounds was performed in multiple-reaction monitoring (MRM) mode using a hybrid quadrupole linear ion trap mass spectrometer equipped with positive/negative ion-switching electrospray ionisation (ESI) source. The developed method is reliable, sensitive and specific. In addition, the method has been successfully applied to differentiate 15 batches of Abri Herba and 27 batches of Abri mollis Herba stems. Furthermore, a comparison of the contents among stems, roots and leaves from the same strain in seven batches of Abri mollis Herba and four batches of Abri Herba has also been performed. HPLC-MS/MS method is sensitive and selective and can be suitable for the reliable quality control of Abri mollis Herba and Abri Herba. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Benzothiazole aniline tetra(ethylene glycol) and 3-amino-1,2,4-triazole inhibit neuroprotection against amyloid peptides by catalase overexpression in vitro.

    Science.gov (United States)

    Chilumuri, Amrutha; Odell, Mark; Milton, Nathaniel G N

    2013-11-20

    Alzheimer's disease, Familial British dementia, Familial Danish dementia, Type 2 diabetes mellitus, plus Creutzfeldt-Jakob disease are associated with amyloid fibril deposition and oxidative stress. The antioxidant enzyme catalase is a neuroprotective amyloid binding protein. Herein the effects of catalase overexpression in SH-SY5Y neuronal cells on the toxicity of amyloid-β (Aβ), amyloid-Bri (ABri), amyloid-Dan (ADan), amylin (IAPP), and prion protein (PrP) peptides were determined. Results showed catalase overexpression was neuroprotective against Aβ, ABri, ADan, IAPP, and PrP peptides. The catalase inhibitor 3-amino-1,2,4-triazole (3-AT) and catalase-amyloid interaction inhibitor benzothiazole aniline tetra(ethylene glycol) (BTA-EG4) significantly enhanced neurotoxicity of amyloid peptides in catalase overexpressing neuronal cells. This suggests catalase neuroprotection involves breakdown of hydrogen peroxide (H2O2) plus a direct binding interaction between catalase and the Aβ, ABri, ADan, IAPP, and PrP peptides. Kisspeptin 45-50 had additive neuroprotective actions against the Aβ peptide in catalase overexpressing cells. The effects of 3-AT had an intracellular site of action, while catalase-amyloid interactions had an extracellular component. These results suggest that the 3-AT and BTA-EG4 compounds may be able to inhibit endogenous catalase mediated neuroprotection. Use of BTA-EG4, or compounds that inhibit catalase binding to amyloid peptides, as potential therapeutics for Neurodegenerative diseases may therefore result in unwanted effects.

  3. Benzothiazole Aniline Tetra(ethylene glycol) and 3-Amino-1,2,4-triazole Inhibit Neuroprotection against Amyloid Peptides by Catalase Overexpression in Vitro

    Science.gov (United States)

    2013-01-01

    Alzheimer’s disease, Familial British dementia, Familial Danish dementia, Type 2 diabetes mellitus, plus Creutzfeldt-Jakob disease are associated with amyloid fibril deposition and oxidative stress. The antioxidant enzyme catalase is a neuroprotective amyloid binding protein. Herein the effects of catalase overexpression in SH-SY5Y neuronal cells on the toxicity of amyloid-β (Aβ), amyloid-Bri (ABri), amyloid-Dan (ADan), amylin (IAPP), and prion protein (PrP) peptides were determined. Results showed catalase overexpression was neuroprotective against Aβ, ABri, ADan, IAPP, and PrP peptides. The catalase inhibitor 3-amino-1,2,4-triazole (3-AT) and catalase-amyloid interaction inhibitor benzothiazole aniline tetra(ethylene glycol) (BTA-EG4) significantly enhanced neurotoxicity of amyloid peptides in catalase overexpressing neuronal cells. This suggests catalase neuroprotection involves breakdown of hydrogen peroxide (H2O2) plus a direct binding interaction between catalase and the Aβ, ABri, ADan, IAPP, and PrP peptides. Kisspeptin 45–50 had additive neuroprotective actions against the Aβ peptide in catalase overexpressing cells. The effects of 3-AT had an intracellular site of action, while catalase-amyloid interactions had an extracellular component. These results suggest that the 3-AT and BTA-EG4 compounds may be able to inhibit endogenous catalase mediated neuroprotection. Use of BTA-EG4, or compounds that inhibit catalase binding to amyloid peptides, as potential therapeutics for Neurodegenerative diseases may therefore result in unwanted effects. PMID:23968537

  4. The Role of ABRI in the Post-Suharto Era

    Science.gov (United States)

    1999-06-04

    Nations. It includes Philippines, Thailand, Malaysia , Singapore, Indonesia, Brunei, Vietnam, Laos and Myanmar. DPR. Dewan Perwakilan Rakyat . People’s...Suharto’s rule from 1965 to 1998. 5Indonesia has territorial disputes with Malaysia over the Sipadan and Ligitan Islands and the Kalimantan border. It...of the ABRI’s role will be captured. The research design is summarized in figure 2. Existing models E.g. Thailand, Burma, - Malaysia . Latin America r

  5. ÉTUDE EXPÉRIMENTALE DES COMPORTEMENTS DE CIVELLES D’ANGUILLA ANGUILLA L. INFLUENCE DE LA DENSITÉ ET DE LA DISPONIBILITÉ EN ABRIS

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    BARDONNET A.

    2005-10-01

    Full Text Available Les comportements d’émigration et d’utilisation de l’espace développés par des civelles ont été observés dans des bacs et plans d’eau expérimentaux. Dans les bacs accueillant 55 ind./m2 sans possibilité d’émigration, la densité d’abris végétaux a été contrôlée (densités d’abris basse, 2 tiges de végétation artificielle par bac ou haute, 9 tiges par bac et le suivi a duré 2 mois et demi. Dans les plans d’eau ouverts, la densité de civelles introduites a été définie selon plusieurs modalités (1,6 - 6 - 9 et 12 ind./m2 et le suivi a duré 1 mois et demi. En bacs, après une période de 5 à 6 jours, les abris sont fortement recherchés pendant environ 6 semaines, les individus montrant alors une forte grégarité. Cette dernière disparaît ensuite, les abris sont alors moins recherchés et des comportements agressifs font leur apparition. En plans d’eau, les sorties concernent en moyenne 17 % du stock initial (mini = 7 %, maxi = 35 %, interviennent rapidement et sont presque toutes dirigées vers l’amont. Leur intensité ne dépend pas de la densité initiale et apparaît plus importante dans les bassins sans herbier. Les tailles et poids moyens des émigrants sont plus importants que ceux du lot initial. Au terme du suivi, la croissance apparaît forte, hétérogène et associée à une faible survie dans les plans d’eau peu ou moyennement alevinés. Elle apparaît plus faible, homogène et associée à une bonne survie dans les bassins à forte densité initiale. Ces observations sont compatibles avec l’expression d’un comportement grégaire en condition de densité importante, comportement favorisant une croissance homogène, ayant pour conséquence de retarder l’apparition d’actes agressifs. Au contraire, dans des contextes de faible densité, l’expression rapide du potentiel de croissance de quelques individus favoriserait l’apparition d’actes agressifs.

  6. Context and dating of Aurignacian vulvar representations from Abri Castanet, France

    Science.gov (United States)

    White, Randall; Mensan, Romain; Bourrillon, Raphaëlle; Cretin, Catherine; Higham, Thomas F. G.; Clark, Amy E.; Sisk, Matthew L.; Tartar, Elise; Gardère, Philippe; Goldberg, Paul; Pelegrin, Jacques; Valladas, Hélène; Tisnérat-Laborde, Nadine; de Sanoit, Jacques; Chambellan, Dominique; Chiotti, Laurent

    2012-01-01

    We report here on the 2007 discovery, in perfect archaeological context, of part of the engraved and ocre-stained undersurface of the collapsed rockshelter ceiling from Abri Castanet, Dordogne, France. The decorated surface of the 1.5-t roof-collapse block was in direct contact with the exposed archaeological surface onto which it fell. Because there was no sedimentation between the engraved surface and the archaeological layer upon which it collapsed, it is clear that the Early Aurignacian occupants of the shelter were the authors of the ceiling imagery. This discovery contributes an important dimension to our understanding of the earliest graphic representation in southwestern France, almost all of which was discovered before modern methods of archaeological excavation and analysis. Comparison of the dates for the Castanet ceiling and those directly obtained from the Chauvet paintings reveal that the “vulvar” representations from southwestern France are as old or older than the very different wall images from Chauvet. PMID:22586111

  7. Amide I SFG Spectral Line Width Probes the Lipid-Peptide and Peptide-Peptide Interactions at Cell Membrane In Situ and in Real Time.

    Science.gov (United States)

    Zhang, Baixiong; Tan, Junjun; Li, Chuanzhao; Zhang, Jiahui; Ye, Shuji

    2018-06-13

    The balance of lipid-peptide and peptide-peptide interactions at cell membrane is essential to a large variety of cellular processes. In this study, we have experimentally demonstrated for the first time that sum frequency generation vibrational spectroscopy can be used to probe the peptide-peptide and lipid-peptide interactions in cell membrane in situ and in real time by determination of the line width of amide I band of protein backbone. Using a "benchmark" model of α-helical WALP23, it is found that the dominated lipid-peptide interaction causes a narrow line width of the amide I band, whereas the peptide-peptide interaction can markedly broaden the line width. When WALP23 molecules insert into the lipid bilayer, a quite narrow line width of the amide I band is observed because of the lipid-peptide interaction. In contrast, when the peptide lies down on the bilayer surface, the line width of amide I band becomes very broad owing to the peptide-peptide interaction. In terms of the real-time change in the line width, the transition from peptide-peptide interaction to lipid-peptide interaction is monitored during the insertion of WALP23 into 1,2-dipalmitoyl- sn-glycero-3-phospho-(1'- rac-glycerol) (DPPG) lipid bilayer. The dephasing time of a pure α-helical WALP23 in 1-palmitoyl-2-oleoyl- sn-glycero-3-phospho-(1'- rac-glycerol) and DPPG bilayer is determined to be 2.2 and 0.64 ps, respectively. The peptide-peptide interaction can largely accelerate the dephasing time.

  8. Structure-activity relationships of the antimicrobial peptide arasin 1 - and mode of action studies of the N-terminal, proline-rich region.

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    Victoria S Paulsen

    Full Text Available Arasin 1 is a 37 amino acid long proline-rich antimicrobial peptide isolated from the spider crab, Hyas araneus. In this work the active region of arasin 1 was identified through structure-activity studies using different peptide fragments derived from the arasin 1 sequence. The pharmacophore was found to be located in the proline/arginine-rich NH(2 terminus of the peptide and the fragment arasin 1(1-23 was almost equally active to the full length peptide. Arasin 1 and its active fragment arasin 1(1-23 were shown to be non-toxic to human red blood cells and arasin 1(1-23 was able to bind chitin, a component of fungal cell walls and the crustacean shell. The mode of action of the fully active N-terminal arasin 1(1-23 was explored through killing kinetic and membrane permeabilization studies. At the minimal inhibitory concentration (MIC, arasin 1(1-23 was not bactericidal and had no membrane disruptive effect. In contrast, at concentrations of 5×MIC and above it was bactericidal and interfered with membrane integrity. We conclude that arasin 1(1-23 has a different mode of action than lytic peptides, like cecropin P1. Thus, we suggest a dual mode of action for arasin 1(1-23 involving membrane disruption at peptide concentrations above MIC, and an alternative mechanism of action, possibly involving intracellular targets, at MIC.

  9. Two-dimensional 1H NMR experiments show that the 23-residue magain in antibiotic peptide is an α-helix in dodecylphosphocholine micelles, sodium dodecylsulfate micelles, and trifluoroethanol/water solution

    International Nuclear Information System (INIS)

    Gesell, Jennifer; Zasloff, Michael; Opella, Stanley J.

    1997-01-01

    Magainin2 is a 23-residue antibiotic peptide that disrupts the ionic gradient across certain cell membranes. Two-dimensional 1H NMR spectroscopy was used to investigate the structure of the peptide in three of the membrane environments most commonly employed in biophysical studies. Sequence-specific resonance assignments were determined for the peptide in perdeuterated dodecylphosphocholine (DPC) and sodium dodecylsulfate micelles and confirmed for the peptide in 2,2,2-trifluoroethanol solution. The secondary structure is shown to be helical in all of the solvent systems. The NMR data were used as a set of restraints for a simulated annealing protocol that generated a family of three-dimensional structures of the peptide in DPC micelles, which superimposed best between residues 4 and 20. For these residues, the mean pairwise rms difference for the backbone atoms is 0.47 ± 0.10A from the average structure. The calculated peptide structures appear to be curved,with the bend centered at residues Phe12 and Gly13

  10. The reliability of DIVA test based on M2e peptide exceed those based on HA2 or NS1 peptides

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    Simson Tarigan

    2015-06-01

    Full Text Available One of the most important disadvantage of vaccination against avian influenza is that it cannot protect vaccinated birds against infection. When vaccinated poultry are heavily exposed to the virus, prolonged, unrecognised, subclinical infection may persist on the farm. The condition can only be serologically monitored by a DIVA (differentiation of infected from vaccinated animals test, whereas conventional diagnostic tests cannot be used. The DIVA tests based on an antibody response following virus replication is the most appropriate approach. For H5N1 influenza such antibodies includes those to the M2e and NS1 proteins and an epitope on the HA2 subunit (HA_488-516. The purpose of this study was to compare the magnitude of the antibody response in chickens vaccinated and infected with an H5N1 virus strain. For that purpose, sera collected from naïve, vaccinated and infected birds, at 1, 2-3, ≥4 weeks post challenge were used. Antibodies were measured by ELISA using biotinylated synthetic peptides as coating antigens. The peptides used include four NS1 peptides corresponding to different regions of the NS1 protein and HA_488-516and M2e peptides. Peptides were coated onto microtitre plates either directly or via a streptavidin bridge. The results showed that vaccination did not cause antibody conversion to any of the peptides, where as challenged birds developed a high antibody response to M2e but, low response to the NS1 and HA2 peptides. Antibodies to the later peptides were detected only by the streptavidin-peptide ELISA. The ELISA based on NS1 or HA_488-516 peptides, therefore, are not reliable for use as DIVA test in H5N1 avian influenza virus infection

  11. INTERNALIZATION OF ANTIMICROBIAL PEPTIDE ACIPENSIN 1 INTO HUMAN TUMOR CELLS

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    E. S. Umnyakova

    2016-01-01

    Full Text Available Search for new compounds providing delivery of drugs into infected or neoplastic cells, is an important direction of biomedical research. Cell-penetrating peptides are among those compounds, due to their ability to translocate through membranes of eukaryotic cells, serving as potential carriers of various therapeutic agents to the target cells. The aim of present work was to investigate the ability of acipensin 1, an antimicrobial peptide of innate immune system, for in vitro penetration into human tumor cells. Acipensin 1 is a cationic peptide that we have previously isolated from leukocytes of the Russian sturgeon, Acipenser gueldenstaedtii. Capability of acipensin 1 to enter the human erytroleukemia K-562 cells has been investigated for the first time. A biotechnological procedure for producing a recombinant acipensin 1 peptide has been developed. The obtained peptide was conjugated with a fluorescent probe BODIPY FL. By means of confocal microscopy, we have shown that the tagged acipensin 1 rapidly enters into K-562 cells and can be detected in the intracellular space within 5 min after its addition to the cell culture. Using flow cytometry technique, penetration kinetics of the labeled peptide into K-562 cells (at nontoxic micromolar concentrations has been studied. We have observed a rapid internalization of the peptide to the target cells, thus confirming the results of microscopic analysis, i.e, the labeled acipensin was detectable in K-562 cells as soon as wihin 2-3 seconds after its addition to the incubation medium. The maximum of fluorescence was reached within a period of approx. 45 seconds, with further “plateau” at the terms of >100 seconds following cell stimulation with the test compound. These data support the concept, that the antimicrobial peptides of innate immunity system possess the features of cell-penetrating peptides, and allow us to consider the studied sturgeon peptide a promising template for development of new

  12. Adding an Artificial Tail—Anchor to a Peptide-Based HIV-1 Fusion Inhibitor for Improvement of Its Potency and Resistance Profile

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    Shan Su

    2017-11-01

    Full Text Available Peptides derived from the C-terminal heptad repeat (CHR of human immunodeficiency virus type 1 (HIV-1 envelope protein transmembrane subunit gp41, such as T20 (enfuvirtide, can bind to the N-terminal heptad repeat (NHR of gp41 and block six-helix bundle (6-HB formation, thus inhibiting HIV-1 fusion with the target cell. However, clinical application of T20 is limited because of its low potency and genetic barrier to resistance. HP23, the shortest CHR peptide, exhibits better anti-HIV-1 activity than T20, but the HIV-1 strains with E49K mutations in gp41 will become resistant to it. Here, we modified HP23 by extending its C-terminal sequence using six amino acid residues (E6 and adding IDL (Ile-Asp-Leu to the C-terminus of E6, which is expected to bind to the shallow pocket in the gp41 NHR N-terminal region. The newly designed peptide, designated HP23-E6-IDL, was about 2- to 16-fold more potent than HP23 against a broad spectrum of HIV-1 strains and more than 12-fold more effective against HIV-1 mutants resistant to HP23. These findings suggest that addition of an anchor–tail to the C-terminus of a CHR peptide will allow binding with the pocket in the gp41 NHR that may increase the peptide’s antiviral efficacy and its genetic barrier to resistance.

  13. Oxidative Modification of Tryptophan-Containing Peptides

    DEFF Research Database (Denmark)

    Petersen, Jonas; Christensen, Pia Katrine; Nielsen, Mathias T

    2018-01-01

    We herein present a broadly useful method for the chemoselective modification of a wide range of tryptophan-containing peptides. Exposing a tryptophan-containing peptide to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a selective cyclodehydration between the peptide backbone...

  14. Regulation of bone-renal mineral and energy metabolism: the PHEX, FGF23, DMP1, MEPE ASARM pathway.

    Science.gov (United States)

    Rowe, Peter S N

    2012-01-01

    More than 300 million years ago, vertebrates emerged from the vast oceans to conquer gravity and the dry land. With this transition, new adaptations occurred that included ingenious changes in reproduction, waste secretion, and bone physiology. One new innovation, the egg shell, contained an ancestral protein (ovocleidin-116) that likely first appeared with the dinosaurs and was preserved through the theropod lineage in modern birds and reptiles. Ovocleidin-116 is an avian homolog of matrix extracellular phosphoglycoprotein (MEPE) and belongs to a group of proteins called short integrin-binding ligand-interacting glycoproteins (SIBLINGs). These proteins are all localized to a defined region on chromosome 5q in mice and chromosome 4q in humans. A unifying feature of SIBLING proteins is an acidic serine aspartate-rich MEPE-associated motif (ASARM). Recent research has shown that the ASARM motif and the released ASARM peptide have regulatory roles in mineralization (bone and teeth), phosphate regulation, vascularization, soft-tissue calcification, osteoclastogenesis, mechanotransduction, and fat energy metabolism. The MEPE ASARM motif and peptide are physiological substrates for PHEX, a zinc metalloendopeptidase. Defects in PHEX are responsible for X-linked hypophosphatemic rickets (HYP). There is evidence that PHEX interacts with another ASARM motif containing SIBLING protein, dentin matrix protein-1 (DMP1). DMP1 mutations cause bone and renal defects that are identical with the defects caused by a loss of PHEX function. This results in autosomal recessive hypophosphatemic rickets (ARHR). In both HYP and ARHR, increased FGF23 expression plays a major role in the disease and in autosomal dominant hypophosphatemic rickets (ADHR), FGF23 half-life is increased by activating mutations. ASARM peptide administration in vitro and in vivo also induces increased FGF23 expression. FGF23 is a member of the fibroblast growth factor (FGF) family of cytokines, which surfaced 500

  15. Structural Insights into the Mechanisms of Action of Short-Peptide HIV-1 Fusion Inhibitors Targeting the Gp41 Pocket

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    Xiujuan Zhang

    2018-02-01

    Full Text Available The deep hydrophobic pocket of HIV-1 gp41 has been considered a drug target, but short-peptides targeting this site usually lack potent antiviral activity. By applying the M-T hook structure, we previously generated highly potent short-peptide fusion inhibitors that specifically targeted the pocket site, such as MT-SC22EK, HP23L, and LP-11. Here, the crystal structures of HP23L and LP-11 bound to the target mimic peptide N36 demonstrated the critical intrahelical and interhelical interactions, especially verifying that the hook-like conformation was finely adopted while the methionine residue was replaced by the oxidation-less prone residue leucine, and that addition of an extra glutamic acid significantly enhanced the binding and inhibitory activities. The structure of HP23L bound to N36 with two mutations (E49K and L57R revealed the critical residues and motifs mediating drug resistance and provided new insights into the mechanism of action of inhibitors. Therefore, the present data help our understanding for the structure-activity relationship (SAR of HIV-1 fusion inhibitors and facilitate the development of novel antiviral drugs.

  16. Architecture naturelle et architecture symbolique au Néolithique. L’exemple des abris peints des gorges de la Nesque (Vaucluse, France

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    Philippe HAMEAU

    2009-12-01

    Full Text Available RÉSUMÉ: L’expression schématique rupestre, pariétale ou mobilière du Néolithique dans le sud de la France est à placer, essentiellement, aux IVe et IIIe millénaires av.J.C. Pourtant, certaines peintures pourraient être plus anciennes et le décor céramique est de style schématique dès le Néolithique ancien. On décrit ici un groupe de dix abris ornés dans un contexte de gorges: leur topographie, leurs peintures et éventuellement leur mobilier archéologique. La diversité des teintes utilisées et des cas de superpositions de traits nous font supposer plusieurs phases graphiques et une complémentarité des sites. Malgré leur apparente disparité, ces abris répondent à des critères précis qui déterminent leur choix par les Néolithiques, notamment la présence d’un ruissellement périodique. A ce titre, plusieurs concrétions résultant des écoulements d’eau sont rehaussées de colorant rouge. Deux abris sont manifestement des sites de réclusion: la condamnation du couloir du premier, le perchement du second, isolent automatiquement leurs usagers du reste de la communauté. En outre, leurs particularités topographiques et pariétales en font des sites propices à des rites de passage. Par comparaison, les grands porches seraient plutôt des lieux de rassemblement. Toutes ces hypothèses traduisent une volonté de considérer les singularités naturelles des lieux (gorges, abris, parois comme autant d’éléments symboliques participant à la constitution des sanctuaires au Néolithique.RESUMEN: La expresión esquemática rupestre, parietal o mobiliaria del Neolítico en el sur de Francia, se tiene que integrar, principalmente, en los IV y III milenios a.C. A pesar de todo, algunas pinturas podrían ser más antiguas y la decoración cerámica es de estilo esquemático desde el Neolítico antiguo. Se describe aquí un grupo de diez abrigos pintados en un contexto de gargantas: su topografía, sus pinturas y

  17. E-Peptides Control Bioavailability of IGF-1

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    Piszczek, Agnieszka; Perlas, Emarald; Winn, Nadine; Nastasi, Tommaso; Rosenthal, Nadia

    2012-01-01

    Insulin-like growth factor 1 (IGF-1) is a potent cytoprotective growth factor that has attracted considerable attention as a promising therapeutic agent. Transgenic over-expression of IGF-1 propeptides facilitates protection and repair in a broad range of tissues, although transgenic mice over-expressing IGF-1 propeptides display little or no increase in IGF-1 serum levels, even with high levels of transgene expression. IGF-1 propeptides are encoded by multiple alternatively spliced transcripts including C-terminal extension (E) peptides, which are highly positively charged. In the present study, we use decellularized mouse tissue to show that the E-peptides facilitate in vitro binding of murine IGF-1 to the extracellular matrix (ECM) with varying affinities. This property is independent of IGF-1, since proteins consisting of the E-peptides fused to relaxin, a related member of the insulin superfamily, bound equally avidly to decellularized ECM. Thus, the E-peptides control IGF-1 bioavailability by preventing systemic circulation, offering a potentially powerful way to tether IGF-1 and other therapeutic proteins to the site of synthesis and/or administration. PMID:23251442

  18. NMR structure of the Arctic mutation of the Alzheimer's Aβ(1-40) peptide docked to SDS micelles

    Science.gov (United States)

    Usachev, K. S.; Filippov, A. V.; Khairutdinov, B. I.; Antzutkin, O. N.; Klochkov, V. V.

    2014-11-01

    The “Arctic” point mutation of the Alzheimer's amyloid β-peptide is a rare mutation leading to an early onset of Alzheimer's disease. The peptide may interact with neuronal membranes, where it can provide its toxic effects. We used 2D NMR spectroscopy to investigate the conformation of the “Arctic” mutant of Aβ1-40 Alzheimer's amyloid peptide in sodium dodecyl sulfate micelle solutions, which are the type of amphiphilic structures mimicking some properties of biomembranes. The study showed that the Arctic mutant of Aβ1-40 interacts with the surface of SDS micelles mainly through the Leu17-Asn27 310-helical region, while the Ile31-Val40 region is buried in the hydrophobic interior of the micelle. In contrast, wild-type Aβ1-40 interacts with SDS micelles through the Lys16-Asp23 α-helical region and Gly29-Met35. Both the Arctic mutant and the wild-type Aβ1-40 peptides interactions with SDS micelles are hydrophobic in nature. Aβ peptides are thought to be capable of forming pores in biomembranes that can cause changes in neuronal and endothelial cell membrane permeability. It has also been shown that Aβ peptides containing the “Arctic” mutation are more neurotoxic and aggregate more readily than the wild-type Aβ peptides at physiological conditions. Here, we propose that the extension of the helical structure of Leu17-Asn27 and a high aliphaticity (neutrality) of the C-terminal region in the Arctic Aβ peptides are consistent with the idea that formation of ion-permeable pores by Aβ oligomers may be one of prevailing mechanisms of a larger neuronal toxicity of the Arctic Aβ compared to the wild-type Aβ peptides, independent of oxidative damage and lipid peroxidation.

  19. Revisiting and re-engineering the classical zinc finger peptide: consensus peptide-1 (CP-1).

    Science.gov (United States)

    Besold, Angelique N; Widger, Leland R; Namuswe, Frances; Michalek, Jamie L; Michel, Sarah L J; Goldberg, David P

    2016-04-01

    Zinc plays key structural and catalytic roles in biology. Structural zinc sites are often referred to as zinc finger (ZF) sites, and the classical ZF contains a Cys2His2 motif that is involved in coordinating Zn(II). An optimized Cys2His2 ZF, named consensus peptide 1 (CP-1), was identified more than 20 years ago using a limited set of sequenced proteins. We have reexamined the CP-1 sequence, using our current, much larger database of sequenced proteins that have been identified from high-throughput sequencing methods, and found the sequence to be largely unchanged. The CCHH ligand set of CP-1 was then altered to a CAHH motif to impart hydrolytic activity. This ligand set mimics the His2Cys ligand set of peptide deformylase (PDF), a hydrolytically active M(II)-centered (M = Zn or Fe) protein. The resultant peptide [CP-1(CAHH)] was evaluated for its ability to coordinate Zn(II) and Co(II) ions, adopt secondary structure, and promote hydrolysis. CP-1(CAHH) was found to coordinate Co(II) and Zn(II) and a pentacoordinate geometry for Co(II)-CP-1(CAHH) was implicated from UV-vis data. This suggests a His2Cys(H2O)2 environment at the metal center. The Zn(II)-bound CP-1(CAHH) was shown to adopt partial secondary structure by 1-D (1)H NMR spectroscopy. Both Zn(II)-CP-1(CAHH) and Co(II)-CP-1(CAHH) show good hydrolytic activity toward the test substrate 4-nitrophenyl acetate, exhibiting faster rates than most active synthetic Zn(II) complexes.

  20. Electrostatics and Flexibility Drive Membrane Recognition and Early Penetration by Antimicrobial Peptide Dendrimer bH1

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, Harish Kumar; Stach, Michaela; Soares, Thereza A.; Darbre, Tamis; Reymond, Jean-Louis; Cascella, Michele

    2013-08-01

    Molecular dynamics simulation of polycationic antimicrobial peptide dendrimer bH1 (Leu)8(DapLeu)4(DapPhe)2DapLys- NH2 binding to membranes suggest that electrostatic 10 interactions with the polyanionic lipopolysaccharide (LPS) and conformational flexibility of the 2,3-diaminopropanoic acid (Dap) branching units drive its selective insertion into microbial membranes.

  1. Effect of glucagon-like peptide-1 on alpha- and beta-cell function in C-peptide-negative type 1 diabetic patients

    DEFF Research Database (Denmark)

    Kielgast, Urd; Asmar, Meena; Madsbad, Sten

    2010-01-01

    The mechanism by which glucagon-like peptide-1 (GLP-1) suppresses glucagon secretion is uncertain, and it is not determined whether endogenous insulin is a necessary factor for this effect.......The mechanism by which glucagon-like peptide-1 (GLP-1) suppresses glucagon secretion is uncertain, and it is not determined whether endogenous insulin is a necessary factor for this effect....

  2. Multiple Factors Related to the Secretion of Glucagon-Like Peptide-1

    Directory of Open Access Journals (Sweden)

    XingChun Wang

    2015-01-01

    Full Text Available The glucagon-like peptide-1 is secreted by intestinal L cells in response to nutrient ingestion. It regulates the secretion and sensitivity of insulin while suppressing glucagon secretion and decreasing postprandial glucose levels. It also improves beta-cell proliferation and prevents beta-cell apoptosis induced by cytotoxic agents. Additionally, glucagon-like peptide-1 delays gastric emptying and suppresses appetite. The impaired secretion of glucagon-like peptide-1 has negative influence on diabetes, hyperlipidemia, and insulin resistance related diseases. Thus, glucagon-like peptide-1-based therapies (glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are now well accepted in the management of type 2 diabetes. The levels of glucagon-like peptide-1 are influenced by multiple factors including a variety of nutrients. The component of a meal acts as potent stimulants of glucagon-like peptide-1 secretion. The levels of its secretion change with the intake of different nutrients. Some drugs also have influence on GLP-1 secretion. Bariatric surgery may improve metabolism through the action on GLP-1 levels. In recent years, there has been a great interest in developing effective methods to regulate glucagon-like peptide-1 secretion. This review summarizes the literature on glucagon-like peptide-1 and related factors affecting its levels.

  3. Lutte contre le Bremia de la laitue en pépinière et sous abri froid : compte-rendu d'essai 2005

    OpenAIRE

    Lambion, Jérôme

    2006-01-01

    Le mildiou de la laitue (Bremia lactucae) est la maladie la plus redoutée sur cette espèce, notamment en culture biologique d’hiver sous abris. En Provence, les dégâts sont très importants, parfois dès la pépinière, et entraînent de fortes pertes financières. Cette situation est due à deux facteurs principaux : d’une part au contournement récurrent des résistances génétiques par de nouvelles souches de Bremia (25 races déterminées à ce jour), et d’autre part à la faiblesse des méthodes de lut...

  4. Mimicking protein-protein interactions through peptide-peptide interactions: HIV-1 gp120 and CXCR4

    Directory of Open Access Journals (Sweden)

    Andrea eGross

    2013-09-01

    Full Text Available We have recently designed a soluble synthetic peptide that functionally mimics the HIV-1 coreceptor CXCR4, which is a chemokine receptor that belongs to the family of seven-transmembrane GPCRs. This CXCR4 mimetic peptide, termed CX4-M1, presents the three extracellular loops (ECLs of the receptor. In binding assays involving recombinant proteins, as well as in cellular infection assays, CX4-M1 was found to selectively recognize gp120 from HIV-1 strains that use CXCR4 for cell entry (X4 tropic HIV-1. Furthermore, anti-HIV-1 antibodies modulate this interaction in a molecular mechanism related to that of their impact on the gp120-CXCR4 interaction. We could now show that the selectivity of CX4-M1 pertains not only to gp120 from X4 tropic HIV-1, but also to synthetic peptides presenting the V3 loops of these gp120 proteins. The V3 loop is thought to be an essential part of the coreceptor binding site of gp120 that contacts the second ECL of the coreceptor. We were able to experimentally confirm this notion in binding assays using substitution analogs of CX4-M1 and the V3 loop peptides, respectively, as well as in cellular infection assays. These results indicate that interactions of the HIV-1 Env with coreceptors can be mimicked by synthetic peptides, which may be useful to explore these interactions at the molecular level in more detail.

  5. Glycotriazole-peptides derived from the peptide HSP1: synergistic effect of triazole and saccharide rings on the antifungal activity.

    Science.gov (United States)

    Junior, Eduardo F C; Guimarães, Carlos F R C; Franco, Lucas L; Alves, Ricardo J; Kato, Kelly C; Martins, Helen R; de Souza Filho, José D; Bemquerer, Marcelo P; Munhoz, Victor H O; Resende, Jarbas M; Verly, Rodrigo M

    2017-08-01

    This work proposes a strategy that uses solid-phase peptide synthesis associated with copper(I)-catalyzed azide alkyne cycloaddition reaction to promote the glycosylation of an antimicrobial peptide (HSP1) containing a carboxyamidated C-terminus (HSP1-NH 2 ). Two glycotriazole-peptides, namely [p-Glc-trz-G 1 ]HSP1-NH 2 and [p-GlcNAc-trz-G 1 ]HSP1-NH 2 , were prepared using per-O-acetylated azide derivatives of glucose and N-acetylglucosamine in the presence of copper(II) sulfate pentahydrate (CuSO 4 ·5H 2 O) and sodium ascorbate as a reducing agent. In order to investigate the synergistic action of the carbohydrate motif linked to the triazole-peptide structure, a triazole derivative [trz-G 1 ]HSP1-NH 2 was also prepared. A set of biophysical approaches such as DLS, Zeta Potential, SPR and carboxyfluorescein leakage from phospholipid vesicles confirmed higher membrane disruption and lytic activities as well as stronger peptide-LUVs interactions for the glycotriazole-peptides when compared to HSP1-NH 2 and to its triazole derivative, which is in accordance with the performed biological assays: whereas HSP1-NH 2 presents relatively low and [trz-G 1 ]HSP1-NH 2 just moderate fungicidal activity, the glycotriazole-peptides are significantly more effective antifungal agents. In addition, the glycotriazole-peptides and the triazole derivative present strong inhibition effects on ergosterol biosynthesis in Candida albicans, when compared to HSP1-NH 2 alone. In conclusion, the increased fungicidal activity of the glycotriazole-peptides seems to be the result of (A) more pronounced membrane-disruptive properties, which is related to the presence of a saccharide ring, together with (B) the inhibition of ergosterol biosynthesis, which seems to be related to the presence of both the monosaccharide and the triazole rings.

  6. A cardioactive peptide from the southern armyworm, Spodoptera eridania.

    Science.gov (United States)

    Furuya, K; Hackett, M; Cirelli, M A; Schegg, K M; Wang, H; Shabanowitz, J; Hunt, D F; Schooley, D A

    1999-01-01

    A cardioactive peptide was isolated from extracts of whole heads of the southern armyworm, Spodoptera eridania. This peptide has the sequence ENFAVGCTPGYQRTADGRCKPTF (Mr = 2516.8), determined from both Edman sequencing and tandem mass spectrometry in combination with off-line micropreparative capillary liquid chromatography. This peptide, termed Spoer-CAP23, has excitatory effects on a semi-isolated heart from larval Manduca sexta, causing an inotropic effect at low concentrations of peptide and chronotropic and inotropic effects at high doses. The threshold concentration for stimulatory effects of the synthetic peptide on the semi-isolated heart was about 1 nM, suggesting a physiological role as a neuropeptide.

  7. Serum peptides as putative modulators of inflammation in psoriasis.

    Science.gov (United States)

    Matsuura, Tetsuhiko; Sato, Masaaki; Nagai, Kouhei; Sato, Toshiyuki; Arito, Mitsumi; Omoteyama, Kazuki; Suematsu, Naoya; Okamoto, Kazuki; Kato, Tomohiro; Soma, Yoshinao; Kurokawa, Manae S

    2017-07-01

    Psoriasis is a refractory inflammatory disease, however, its pathophysiology is still not fully understood. We tried to identify novel serum peptides associated with the pathophysiology of psoriasis. Serum peptides from 24 patients with psoriasis vulgaris (PV), 10 patients with psoriatic arthritis (PsA), 14 patients with atopic dermatitis (AD), and 23 healthy control (HC) subjects were analyzed by mass spectrometry. The effects of some peptides on the secretion of humoral factors from dermal cells were investigated by cytokine arrays and ELISAs. A total of 93 peptides were detected. 24, 20, 23, and 2 peptides showed at least 1.2-fold difference in ion intensity between the psoriasis (PV+PsA) and HC groups, between the PV+PsA and AD groups, between the PV and PsA groups, and between patients with severe-to-moderate PV (n=6) and those with mild PV (n=18), respectively (ppsoriasis, regulating the secretion of inflammatory chemokines and an antimicrobial protein. The modulation of serum peptides may be a potential therapeutic strategy for psoriasis. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  8. Atrial natriuretic peptide and red cell 2,3-diphosphoglycerate in patients with chronic mountain sickness.

    Science.gov (United States)

    Ge, R L; Shai, H R; Takeoka, M; Hanaoka, M; Koizumi, T; Matsuzawa, Y; Kubo, K; Kobayashi, T

    2001-01-01

    Individuals with chronic mountain sickness (CMS) show severe hypoxemia, excessive polycythemia, and marked pulmonary hypertension. The pathophysiologic mechanisms of CMS are still not completely understood. We determined plasma atrial natriuretic peptide (ANP), red cell 2,3-diphosphoglycerate (2,3-DPG), hematocrit, hemoglobin, and arterialized ear lobe blood gas values in 13 patients with CMS (9 Hans, 4 Tibetans) and 18 control Han Chinese men of similar age, height, and weight who had been living at 4300 m on the Tibetan plateau of Qinghai Province, China, for approximately 14 years. A significantly higher level of ANP was found in the CMS patients compared to the non-CMS patients (113.4+/-5.5 pg/mL vs 87.6+/-4.7 pg/mL, P levels of ANP correlated positively with the hemoglobin concentration (r = 0.8282, P levels in the CMS patients were significantly increased compared to the non-CMS subjects (5.23+/-0.16 mmol/L vs 4.40+/-0.12 mmol/L, P levels, lower pH values, lower PaO2 levels, and greater alveolar-arterial oxygen differences (PAO2 - PaO2) compared to the non-CMS subjects. These findings suggest that overproduction of ANP and 2,3-DPG at high altitudes may play an important role in the pathophysiology of chronic mountain sickness.

  9. Design of peptide substrates for nanosecond time-resolved fluorescence assays of proteases: 2,3-diazabicyclo[2.2.2]oct-2-ene as a noninvasive fluorophore.

    Science.gov (United States)

    Hennig, Andreas; Florea, Mara; Roth, Doris; Enderle, Thilo; Nau, Werner M

    2007-01-15

    Fluorescence protease assays were investigated with peptide substrates containing a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) as a fluorescent amino acid. The special characteristic of the fluorophore Dbo is its exceedingly long fluorescence lifetime (ca. 300 ns in water under air), which allows the use of nanosecond time-resolved fluorescence (Nano-TRF) detection to efficiently suppress shorter-lived background emission. In addition, the natural amino acids tryptophan and tyrosine can be employed as intramolecular fluorescence quenchers, which facilitates substrate design. Fourteen synthetic peptide substrates (composed of 2-19 amino acids) and five enzymes (trypsin, pepsin, carboxypeptidase A, leucine aminopeptidase, and chymotrypsin) were investigated and, in all 28 examined combinations, enzymatic activity was detected by monitoring the increase in steady state fluorescence with time and determining the reaction rates as kcat/Km values, which ranged from 0.2 to 80x10(6) M-1 min-1. The results suggest an excellent compatibility of the very small and hydrophilic fluorescent probe Dbo with solid-phase peptide synthesis and the investigated proteases. For all 14 peptides the fluorescence lifetimes before and after enzymatic cleavage were measured and Nano-TRF measurements were performed in 384-well microplates. The fluorescence lifetimes of the different peptides provide the basis for the rational design of Dbo-based fluorescent substrates for protease assays. Measurements in Nano-TRF mode revealed, in addition to efficient suppression of background fluorescence, an increased differentiation between cleaved and uncleaved substrate. The Dbo-based assays can be adapted for high-throughput screening.

  10. Identification of Four-Jointed Box 1 (FJX1-Specific Peptides for Immunotherapy of Nasopharyngeal Carcinoma.

    Directory of Open Access Journals (Sweden)

    San Jiun Chai

    Full Text Available Nasopharyngeal carcinoma (NPC is highly prevalent in South East Asia and China. The poor outcome is due to late presentation, recurrence, distant metastasis and limited therapeutic options. For improved treatment outcome, immunotherapeutic approaches focusing on dendritic and autologous cytotoxic T-cell based therapies have been developed, but cost and infrastructure remain barriers for implementing these in low-resource settings. As our prior observations had found that four-jointed box 1 (FJX1, a tumor antigen, is overexpressed in NPCs, we investigated if short 9-20 amino acid sequence specific peptides matching to FJX1 requiring only intramuscular immunization to train host immune systems would be a better treatment option for this disease. Thus, we designed 8 FJX1-specific peptides and implemented an assay system to first, assess the binding of these peptides to HLA-A2 molecules on T2 cells. After, ELISPOT assays were used to determine the peptides immunogenicity and ability to induce potential cytotoxicity activity towards cancer cells. Also, T-cell proliferation assay was used to evaluate the potential of MHC class II peptides to stimulate the expansion of isolated T-cells. Our results demonstrate that these peptides are immunogenic and peptide stimulated T-cells were able to induce peptide-specific cytolytic activity specifically against FJX1-expressing cancer cells. In addition, we demonstrated that the MHC class II peptides were capable of inducing T-cell proliferation. Our results suggest that these peptides are capable of inducing specific cytotoxic cytokines secretion against FJX1-expressing cancer cells and serve as a potential vaccine-based therapy for NPC patients.

  11. Identification of Four-Jointed Box 1 (FJX1)-Specific Peptides for Immunotherapy of Nasopharyngeal Carcinoma

    Science.gov (United States)

    Chai, San Jiun; Yap, Yoke Yeow; Foo, Yoke Ching; Yap, Lee Fah; Ponniah, Sathibalan; Teo, Soo Hwang; Cheong, Sok Ching; Patel, Vyomesh; Lim, Kue Peng

    2015-01-01

    Nasopharyngeal carcinoma (NPC) is highly prevalent in South East Asia and China. The poor outcome is due to late presentation, recurrence, distant metastasis and limited therapeutic options. For improved treatment outcome, immunotherapeutic approaches focusing on dendritic and autologous cytotoxic T-cell based therapies have been developed, but cost and infrastructure remain barriers for implementing these in low-resource settings. As our prior observations had found that four-jointed box 1 (FJX1), a tumor antigen, is overexpressed in NPCs, we investigated if short 9–20 amino acid sequence specific peptides matching to FJX1 requiring only intramuscular immunization to train host immune systems would be a better treatment option for this disease. Thus, we designed 8 FJX1-specific peptides and implemented an assay system to first, assess the binding of these peptides to HLA-A2 molecules on T2 cells. After, ELISPOT assays were used to determine the peptides immunogenicity and ability to induce potential cytotoxicity activity towards cancer cells. Also, T-cell proliferation assay was used to evaluate the potential of MHC class II peptides to stimulate the expansion of isolated T-cells. Our results demonstrate that these peptides are immunogenic and peptide stimulated T-cells were able to induce peptide-specific cytolytic activity specifically against FJX1-expressing cancer cells. In addition, we demonstrated that the MHC class II peptides were capable of inducing T-cell proliferation. Our results suggest that these peptides are capable of inducing specific cytotoxic cytokines secretion against FJX1-expressing cancer cells and serve as a potential vaccine-based therapy for NPC patients. PMID:26536470

  12. Human C-peptide. Pt. 1

    International Nuclear Information System (INIS)

    Beischer, W.; Keller, L.; Maas, M.; Schiefer, E.; Pfeiffer, E.F.

    1976-01-01

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with 125 iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. (orig.) [de

  13. Multimerized CHR-derived peptides as HIV-1 fusion inhibitors.

    Science.gov (United States)

    Nomura, Wataru; Hashimoto, Chie; Suzuki, Takaharu; Ohashi, Nami; Fujino, Masayuki; Murakami, Tsutomu; Yamamoto, Naoki; Tamamura, Hirokazu

    2013-08-01

    To date, several HIV-1 fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of an HIV-1 envelope protein gp41 have been discovered. We have shown that a synthetic peptide mimetic of a trimer form of the CHR-derived peptide C34 has potent inhibitory activity against the HIV-1 fusion mechanism, compared to a monomer C34 peptide. The present study revealed that a dimeric form of C34 is evidently structurally critical for fusion inhibitors, and that the activity of multimerized CHR-derived peptides in fusion inhibition is affected by the properties of the unit peptides C34, SC34EK, and T20. The fluorescence-based study suggested that the N36-interactive sites of the C34 trimer, including hydrophobic residues, are exposed outside the trimer and that trimerization of C34 caused a remarkable increase in fusion inhibitory activity. The present results could be useful in the design of fusion inhibitors against viral infections which proceed via membrane fusion with host cells. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. 28 CFR 23.1 - Purpose.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Purpose. 23.1 Section 23.1 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.1 Purpose. The purpose...-647), are utilized in conformance with the privacy and constitutional rights of individuals. ...

  15. Design, synthesis and in vitro evaluation of heterobivalent peptidic radioligands targeting both GRP- and VPAC1-Receptors concomitantly overexpressed on various malignancies - Is the concept feasible?

    Science.gov (United States)

    Lindner, Simon; Fiedler, Luise; Wängler, Björn; Bartenstein, Peter; Schirrmacher, Ralf; Wängler, Carmen

    2018-05-29

    Radiolabeled heterobivalent peptidic ligands (HBPLs), being able to address different receptors, are highly interesting tumor imaging agents as they can offer multiple advantages over monovalent peptide receptor ligands. However, few examples of radiolabeled HBPLs have been described so far. One promising approach is the combination of gastrin-releasing peptide receptor (GRPR)- and vasoactive intestinal peptide receptor subtype 1 (VPAC 1 R)-targeting peptides into one single radioligand since gastrinomas, prostate and breast cancer have been shown to concomitantly or complementarily overexpress both receptors. Here we report the design and synthesis of different HBPLs, comprising a GRPR-binding (BBN 7-14 ) and a VPAC 1 R-targeting (PACAP-27) peptide. The heterodimers were varied with regard to the distance between the peptide binders and the steric rigidity of the systems. We radiolabeled the HBPLs 19-23 as well as their monomeric reference standards 26 and 27 with 68 Ga, achieving radiochemical yields and purities of 95-99% and non-optimized molar activities of 25-61 GBq/μmol. We tested the stability of the radioligands and further evaluated them in vitro regarding their uptake in different prostate carcinoma cell lines (PC-3, DU-145 and VCaP cells). We found that the heterobivalent substances [ 68 Ga]19 - [ 68 Ga]23 showed comparable uptakes into the tumor cells to those of the respective monomers [ 68 Ga]26 and [ 68 Ga]27, indicating that both peptides are still able to address their target receptors. Furthermore, the obtained results indicate that in case of overall low receptor densities, heterobivalent peptides surpass peptide monomers in tumor cell uptake. Most importantly, it could be shown by blocking studies that both peptide parts of the HBPL [ 68 Ga]19 contributed to tumor cell uptake in VCaP cells, expressing both receptor types. Thus, we describe here the first examples of HBPLs being able to address the GRPR as well as the VPAC 1 R and have the

  16. Binding of peptides to HLA-DQ molecules: peptide binding properties of the disease-associated HLA-DQ(alpha 1*0501, beta 1*0201) molecule

    DEFF Research Database (Denmark)

    Johansen, B H; Buus, S; Vartdal, F

    1994-01-01

    Peptide binding to DQ molecules has not previously been described. Here we report a biochemical peptide-binding assay specific for the DQ2 [i.e. DQ(alpha 1*0501, beta 1*0201)] molecule. This molecule was chosen since it shows a strong association to diseases such as celiac disease and insulin...

  17. Glucagon and glucagon-like peptides 1 and 2

    DEFF Research Database (Denmark)

    Holst, Jens Juul

    2010-01-01

    amino acid precursor, proglucagon, leaving behind proglucagon fragments (PG 1-30 and PG 72-158, the so-called major proglucagon fragment (MPGF)) that are probably inactive, the intestinal processing leads to the formation of glicentin (PG 1-69; action uncertain) and glucagon-like peptides 1 (PG 78....... After their release, the hormones are eliminated mainly in the kidneys, but both GLP-2 and in particular GLP-1, but not glucagon, are metabolized both locally and in the circulation and liver by dipeptidyl peptidase 4 (DPP-4) which inactivates the peptides, suggesting that GLP-1 acts locally rather than...

  18. 125I-labeling and purification of peptide hormones and bovine serum albumin

    International Nuclear Information System (INIS)

    Nemeth, J; Jakab, B.; Szilvassy, Z.; Oroszi, G.; Roeth, E.; Magyarlaki, M.; Farkas, B.

    2002-01-01

    The iodination and separation of various diagnostically and/or experimentally important peptides including (Tyr 1 )-somatostatin-14, rat Tyr-α-calcitonin gene-related peptide (23-37), motilin and vasoactive intestinal peptide, furthermore bovine serum albumin are described. All species were iodinated by the iodogen method. The 125 I-labeled peptide products were separated by reversed-phase HPLC, the specific activities of mono-iodinated forms are near identical with the theoretical value. The labeled bovine serum albumin was separated by Sephadex G-100 gel filtration. (author)

  19. The physiology of glucagon-like peptide 1

    DEFF Research Database (Denmark)

    Holst, Jens Juul

    2007-01-01

    Glucagon-like peptide 1 (GLP-1) is a 30-amino acid peptide hormone produced in the intestinal epithelial endocrine L-cells by differential processing of proglucagon, the gene which is expressed in these cells. The current knowledge regarding regulation of proglucagon gene expression in the gut...... and in the brain and mechanisms responsible for the posttranslational processing are reviewed. GLP-1 is released in response to meal intake, and the stimuli and molecular mechanisms involved are discussed. GLP-1 is extremely rapidly metabolized and inactivated by the enzyme dipeptidyl peptidase IV even before...... postprandial glucose excursions. It also inhibits gastrointestinal motility and secretion and thus acts as an enterogastrone and part of the "ileal brake" mechanism. GLP-1 also appears to be a physiological regulator of appetite and food intake. Because of these actions, GLP-1 or GLP-1 receptor agonists...

  20. δ-Peptides from RuAAC-Derived 1,5-Disubstituted Triazole Units

    KAUST Repository

    Johansson, Johan R.

    2014-02-14

    Non-natural peptides with structures and functions similar to natural peptides have emerged lately in biomedical as well as nanotechnological contexts. They are interesting for pharmaceutical applications since they can adopt structures with new targeting potentials and because they are generally not prone to degradation by proteases. We report here a new set of peptidomimetics derived from δ-peptides, consisting of n units of a 1,5-disubstituted 1,2,3-triazole amino acid (5Tzl). The monomer was prepared using ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) chemistry using [RuCl2Cp]x as the catalyst, allowing for simpler purification and resulting in excellent yields. This achiral monomer was used to prepare peptide oligomers that are water soluble independent of peptide chain length. Conformational analysis and structural investigations of the oligomers were performed by 2D NOESY NMR experiments, and by quantum chemical calculations using the ωB97X-D functional. These data indicate that several conformations may co-exist with slight energetic differences. Together with their increased hydrophilicity, this feature of homo-5Tzl may prove essential for mimicking natural peptides composed of α-amino acids, where the various secondary structures are achieved by side chain effects and not by the rigidity of the peptide backbone. The improved synthetic method allows for facile variation of the 5Tzl amino acid side chains, further increasing the versatility of these compounds. A new set of non-natural peptides composed of 1,5-disubstituted 1,2,3-triazole amino acids is presented. These peptides benefit from: a) modular synthesis of the monomers, allowing variation of the side chains; b) increased solubility of the oligomers in water, irrespective of peptide length; c) flexibility of the backbone allowing these foldamers to adopt several conformations. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Radio-immunoassays for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2)

    DEFF Research Database (Denmark)

    Orskov, C; Holst, J J

    1987-01-01

    Gene-sequencing studies have shown that the glucagon precursor contains two additional glucagon-like sequences, the so-called glucagon-like peptides 1 and 2 (GLP-1 and GLP-2). We developed radio-immunoassays against synthetic peptides corresponding to these sequences. Antisera were raised in rabb...

  2. Specificity of RSG-1.2 peptide binding to RRE-IIB RNA element of HIV-1 over Rev peptide is mainly enthalpic in origin.

    Science.gov (United States)

    Kumar, Santosh; Bose, Debojit; Suryawanshi, Hemant; Sabharwal, Harshana; Mapa, Koyeli; Maiti, Souvik

    2011-01-01

    Rev is an essential HIV-1 regulatory protein which binds to the Rev responsive element (RRE) present within the env gene of HIV-1 RNA genome. This binding facilitates the transport of the RNA to the cytoplasm, which in turn triggers the switch between viral latency and active viral replication. Essential components of this complex have been localized to a minimal arginine rich Rev peptide and stem IIB region of RRE. A synthetic peptide known as RSG-1.2 binds with high binding affinity and specificity to the RRE-IIB than the Rev peptide, however the thermodynamic basis of this specificity has not yet been addressed. The present study aims to probe the thermodynamic origin of this specificity of RSG-1.2 over Rev Peptide for RRE-IIB. The temperature dependent melting studies show that RSG-1.2 binding stabilizes the RRE structure significantly (ΔT(m) = 4.3°C), in contrast to Rev binding. Interestingly the thermodynamic signatures of the binding have also been found to be different for both the peptides. At pH 7.5, RSG-1.2 binds RRE-IIB with a K(a) = 16.2±0.6×10(7) M(-1) where enthalpic change ΔH = -13.9±0.1 kcal/mol is the main driving force with limited unfavorable contribution from entropic change TΔS = -2.8±0.1 kcal/mol. A large part of ΔH may be due to specific stacking between U72 and Arg15. In contrast binding of Rev (K(a) = 3.1±0.4×10(7) M(-1)) is driven mainly by entropy (ΔH = 0 kcal/mol and TΔS = 10.2±0.2 kcal/mol) which arises from major conformational changes in the RNA upon binding.

  3. Human C-peptide. Pt. 1. Radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Beischer, W; Keller, L; Maas, M; Schiefer, E; Pfeiffer, E F [Ulm Univ. (Germany, F.R.). Abt. Innere Medizin, Endokrinologie und Stoffwechsel

    1976-08-01

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with /sup 125/iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum.

  4. Glucagon-like peptide-1 analogues: An overview

    Directory of Open Access Journals (Sweden)

    Vishal Gupta

    2013-01-01

    Full Text Available Abnormalities of the incretin axis have been implicated in the pathogenesis of type 2 diabetes mellitus. Glucagon-like peptide-1 (GLP-1 and gastroinhibitory intestinal peptide constitutes >90% of all the incretin function. Augmentation of GLP-1 results in improvement of beta cell health in a glucose-dependant manner (post-prandial hyperglycemia and suppression of glucagon (fasting hyperglycemia, amongst other beneficial pleiotropic effects. Native GLP-1 has a very short plasma half-life and novel methods have been developed to augment its half life, such that its anti-hyperglycemic effects can be exploited. They can be broadly classified as exendin-based therapies (exenatide, exenatide once weekly, DPP-4-resistant analogues (lixisenatide, albiglutide, and analogues of human GLP-1 (liraglutide, taspoglutide. Currently, commercially available analogues are exenatide, exenatide once weekly, and liraglutide. This review aims to provide an overview of most GLP-1 analogues.

  5. Exaggerated secretion of glucagon-like peptide-1 (GLP-1) could cause reactive hypoglycaemia

    DEFF Research Database (Denmark)

    Toft-Nielsen, M; Madsbad, Sten; Holst, Jens Juul

    1998-01-01

    The plasma concentrations of the insulinotropic incretin hormone, glucagon-like peptide-1 (GLP-1) are abnormally high after oral glucose in partially gastrectomised subjects with reactive hypoglycaemia, suggesting a causal relationship. Because of the glucose-dependency of its effects, it is impo......The plasma concentrations of the insulinotropic incretin hormone, glucagon-like peptide-1 (GLP-1) are abnormally high after oral glucose in partially gastrectomised subjects with reactive hypoglycaemia, suggesting a causal relationship. Because of the glucose-dependency of its effects...

  6. Co-localisation of the Kir6.2/SUR1 channel complex with glucagon-like peptide-1 and glucose-dependent insulinotrophic polypeptide expression in human ileal cells and implications for glycaemic control in new onset type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lotte B; Ploug, Kenneth B; Swift, Peter

    2007-01-01

    on glucose-sensing tissues in vivo that may affect the overall glycaemic control in children with new-onset type 1 diabetes. DESIGN AND METHODS: Western blot and immunohistochemical analyses were performed for expression and co-localisation studies. Meal-stimulated C-peptide test was carried out in 257...... children at 1, 6 and 12 months after diagnosis. Genotyping for the Glu23Lys variant was by PCR-restriction fragment length polymorphism. RESULTS: Kir6.2 and SUR1 co-localise with GLP-1 in L-cells and with GIP in K-cells in human ileum tissue. Children with type 1 diabetes carrying the hyperactive Glu23Lys...... with type 1 diabetes....

  7. Halobacterium salinarum NRC-1 PeptideAtlas: strategies for targeted proteomics

    Science.gov (United States)

    Van, Phu T.; Schmid, Amy K.; King, Nichole L.; Kaur, Amardeep; Pan, Min; Whitehead, Kenia; Koide, Tie; Facciotti, Marc T.; Goo, Young-Ah; Deutsch, Eric W.; Reiss, David J.; Mallick, Parag; Baliga, Nitin S.

    2009-01-01

    The relatively small numbers of proteins and fewer possible posttranslational modifications in microbes provides a unique opportunity to comprehensively characterize their dynamic proteomes. We have constructed a Peptide Atlas (PA) for 62.7% of the predicted proteome of the extremely halophilic archaeon Halobacterium salinarum NRC-1 by compiling approximately 636,000 tandem mass spectra from 497 mass spectrometry runs in 88 experiments. Analysis of the PA with respect to biophysical properties of constituent peptides, functional properties of parent proteins of detected peptides, and performance of different mass spectrometry approaches has helped highlight plausible strategies for improving proteome coverage and selecting signature peptides for targeted proteomics. Notably, discovery of a significant correlation between absolute abundances of mRNAs and proteins has helped identify low abundance of proteins as the major limitation in peptide detection. Furthermore we have discovered that iTRAQ labeling for quantitative proteomic analysis introduces a significant bias in peptide detection by mass spectrometry. Therefore, despite identifying at least one proteotypic peptide for almost all proteins in the PA, a context-dependent selection of proteotypic peptides appears to be the most effective approach for targeted proteomics. PMID:18652504

  8. Glucagon-like peptide 1--a cardiologic dimension

    DEFF Research Database (Denmark)

    Treiman, Marek; Elvekjaer, Mikkel; Engstrøm, Thomas

    2010-01-01

    Recent experimental data suggest glucagon-like peptide 1 (GLP-1) and its analogs to have direct effects on the cardiovascular system, in addition to their classic glucoregulatory actions. These direct effects may be cardioprotective, contractility augmenting, and vasorelaxant. A few preliminary c...

  9. Interpreting the Rock Paintings of Abri Faravel: laser and white-light scanning at 2,133m in the southern French Alps

    Directory of Open Access Journals (Sweden)

    Kevin Walsh

    2016-05-01

    Full Text Available The Abri Faravel, discovered in 2010 at 2,133m asl in the Parc National des Ecrins, Freissinières, Southern French Alps, is probably the most enigmatic high altitude site in the Alps. This rock shelter saw phases of human activity from the Mesolithic through to the medieval period; the artefactual assemblages comprise Mesolithic and Neolithic flint tools, Iron Age hand-thrown pottery, a Roman fibula and some medieval metalwork. However, the most interesting and unique feature on the site are the prehistoric rock paintings; the highest representations of animals (quadrupeds in Europe. These paintings are presented in this article. The paintings themselves were the object of a white-light scan, whilst the rock-shelter and surrounding landscape was scanned using a Faro laser scanner. Both of these models are presented here, and their interpretation elucidated by an assessment of the different phases of activity at the shelter, combined with a synthesis of other evidence from the area and pertinent environmental evidence.

  10. δ-Peptides from RuAAC-Derived 1,5-Disubstituted Triazole Units

    KAUST Repository

    Johansson, Johan R.; Hermansson, Elin; Nordé n, Bengt; Kann, Nina; Beke-Somfai, Tamá s

    2014-01-01

    of non-natural peptides composed of 1,5-disubstituted 1,2,3-triazole amino acids is presented. These peptides benefit from: a) modular synthesis of the monomers, allowing variation of the side chains; b) increased solubility of the oligomers in water

  11. β-Klotho as a Negative Regulator of the Peptide Transporters PEPT1 and PEPT2

    Directory of Open Access Journals (Sweden)

    Abeer Abousaab

    2016-12-01

    Full Text Available Background/Aims: β-Klotho, a transmembrane protein expressed in several tissues including the brain and the kidney, is critically important for inhibition of 1,25(OH2D3 formation by FGF23. The extracellular domain of Klotho protein could be cleaved off, thus being released into blood or cerebrospinal fluid. Soluble klotho is a β-glucuronidase participating in the regulation of several ion channels and carriers. The present study explored the effect of β-Klotho protein on the peptide transporters PEPT1 and PEPT2. Methods: cRNA encoding PEPT1 or PEPT2 was injected into Xenopus laevis oocytes and glycine-glycine (2 mM-induced inward current (IGly taken as measure of glycine-glycine transport. Measurements were made without or with prior 24 h treatment with soluble β-Klotho protein (30 ng/ml in the absence and presence of β-glucuronidase inhibitor D-saccharic acid 1,4-lactone monohydrate (DSAL,10 µM. Ussing chamber experiments were employed to determine electrogenic peptide transport across intestinal epithelia of klotho deficient (kl-/- and corresponding wild type (kl+/+ mice. Results: IGly was observed in PEPT1 and in PEPT2 expressing oocytes but not in water injected oocytes. In both, PEPT1 and PEPT2 expressing oocytes IGly was significantly decreased by treatment with soluble β-Klotho protein. As shown for PEPT1, β-klotho protein decreased significantly the maximal transport rate without significantly modifying the affinity of the carrier. The effect of β-Klotho on PEPT1 was reversed by DSAL. Intestinal IGly was significantly larger in kl-/- than in kl+/+ mice. Conclusion: β-Klotho participates in the regulation of the peptide transporters PEPT1 and PEPT2.

  12. Preclinical evaluation of "1"1"1In-DOTA-Bombesin analogue for peptide receptor targeted imaging

    International Nuclear Information System (INIS)

    Salgueiro, C.; Castiglia, S.G. de; Tesan, F.; Salgueiro, M.J.

    2017-01-01

    Peptide receptors are very important targets for imaging and therapy. The bombesin family is becoming significant, in special the gastrine-releasing peptide receptor (GRPr) that has been found in Prostate and Breast tumors. The aim of this work is to label [DOTA-Pro1,Tyr4] BN with "1"1"1InCl3 and study its efficacy in normal and tumor animals. Radiolabeling experiences were made to find the best peptide : radionuclide relationship. The radiochemical purity was determined by Sep-pak C18 cartridge (Waters) and ITLC-SG using 50mM EDTA in 0.1M ammonium acetate (pH 5.5) and 3.5%(v/v) ammonia/methanol 1:1. Gamma imaging studies were made 24 hs after injection of the product in control rats. On the other hand gamma imaging studies were made at 24 hs in tumor bearing nude mice too. The tumor was induced by subcutaneous injection of PC3 cells. For biodistribution studies animals were sacrificed and blood, pancreas, intestine, kidneys, liver, lungs, femoral muscle and tumor were analyzed. The results were expressed as %ID/g of tissue. Radiolabeling experiments allowed us to obtain an stable product with >95% of radiochemical purity and 5.78MBq/nmol of specific activity, with a ratio of 13μg peptide per In-111 mCi. The normal and tumor animals imaging show physiological uptake in kidneys and a biodistribution according to bibliography. A specific uptake is evidenced in tumor. Our results show a radiochemical stable compound for 48 hs and suitable for GRPr imaging. (authors) [es

  13. Critical 23S rRNA interactions for macrolide-dependent ribosome stalling on the ErmCL nascent peptide chain.

    Science.gov (United States)

    Koch, Miriam; Willi, Jessica; Pradère, Ugo; Hall, Jonathan; Polacek, Norbert

    2017-06-20

    The nascent peptide exit tunnel has recently been identified as a functional region of ribosomes contributing to translation regulation and co-translational protein folding. Inducible expression of the erm resistance genes depends on ribosome stalling at specific codons of an upstream open reading frame in the presence of an exit tunnel-bound macrolide antibiotic. The molecular basis for this translation arrest is still not fully understood. Here, we used a nucleotide analog interference approach to unravel important functional groups on 23S rRNA residues in the ribosomal exit tunnel for ribosome stalling on the ErmC leader peptide. By replacing single nucleobase functional groups or even single atoms we were able to demonstrate the importance of A2062, A2503 and U2586 for drug-dependent ribosome stalling. Our data show that the universally conserved A2062 and A2503 are capable of forming a non-Watson-Crick base pair that is critical for sensing and transmitting the stalling signal from the exit tunnel back to the peptidyl transferase center of the ribosome. The nucleobases of A2062, A2503 as well as U2586 do not contribute significantly to the overall mechanism of protein biosynthesis, yet their elaborate role for co-translational monitoring of nascent peptide chains inside the exit tunnel can explain their evolutionary conservation. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Steviol Glycoside Rebaudioside A Induces Glucagon-like Peptide-1 and Peptide YY Release in a Porcine ex Vivo Intestinal Model

    NARCIS (Netherlands)

    Ripken, D.; Wielen, N. van der; Wortelboer, H.M.; Meijerink, J.; Witkamp, R.F.; Hendriks, H.F.J.

    2014-01-01

    Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are hormones important for satiation and are involved in the process called “ileal brake”. The aim of this study was to investigate the GLP-1- and PYY-stimulating efficacy of rebaudioside A, casein, and sucrose. This was studied using tissue

  15. Steviol glycoside rebaudioside A induces glucagon-like peptide-1 and peptide YY release in a porcine ex vivo intestinal model

    NARCIS (Netherlands)

    Ripken, D.; Wielen, van der N.; Wortelboer, H.M.; Meijerink, J.; Witkamp, R.F.; Hendriks, H.F.

    2014-01-01

    Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are hormones important for satiation and are involved in the process called "ileal brake". The aim of this study was to investigate the GLP-1- and PYY-stimulating efficacy of rebaudioside A, casein, and sucrose. This was studied using tissue

  16. Development of Highly Selective Kv1.3-Blocking Peptides Based on the Sea Anemone Peptide ShK

    Directory of Open Access Journals (Sweden)

    Michael W. Pennington

    2015-01-01

    Full Text Available ShK, from the sea anemone Stichodactyla helianthus, is a 35-residue disulfide-rich peptide that blocks the voltage-gated potassium channel Kv1.3 at ca. 10 pM and the related channel Kv1.1 at ca. 16 pM. We developed an analog of this peptide, ShK-186, which is currently in Phase 1b-2a clinical trials for the treatment of autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. While ShK-186 displays a >100-fold improvement in selectivity for Kv1.3 over Kv1.1 compared with ShK, there is considerable interest in developing peptides with an even greater selectivity ratio. In this report, we describe several variants of ShK that incorporate p-phophono-phenylalanine at the N-terminus coupled with internal substitutions at Gln16 and Met21. In addition, we also explored the combinatorial effects of these internal substitutions with an alanine extension at the C-terminus. Their selectivity was determined by patch-clamp electrophysiology on Kv1.3 and Kv1.1 channels stably expressed in mouse fibroblasts. The peptides with an alanine extension blocked Kv1.3 at low pM concentrations and exhibited up to 2250-fold selectivity for Kv1.3 over Kv1.1. Analogs that incorporates p-phosphono-phenylalanine at the N-terminus blocked Kv1.3 with IC50s in the low pM range and did not affect Kv1.1 at concentrations up to 100 nM, displaying a selectivity enhancement of >10,000-fold for Kv1.3 over Kv1.1. Other potentially important Kv channels such as Kv1.4 and Kv1.6 were only partially blocked at 100 nM concentrations of each of the ShK analogs.

  17. Glucagon-like peptide 1 (GLP-1) suppresses ghrelin levels in humans via increased insulin secretion

    DEFF Research Database (Denmark)

    Hagemann, Dirk; Holst, Jens Juul; Gethmann, Arnica

    2007-01-01

    INTRODUCTION: Ghrelin is an orexigenic peptide predominantly secreted by the stomach. Ghrelin plasma levels rise before meal ingestion and sharply decline afterwards, but the mechanisms controlling ghrelin secretion are largely unknown. Since meal ingestion also elicits the secretion...... of the incretin hormone glucagon-like peptide 1 (GLP-1), we examined whether exogenous GLP-1 administration reduces ghrelin secretion in humans. PATIENTS AND METHODS: 14 healthy male volunteers were given intravenous infusions of GLP-1(1.2 pmol x kg(-1) min(-1)) or placebo over 390 min. After 30 min, a solid test...... meal was served. Venous blood was drawn frequently for the determination of glucose, insulin, C-peptide, GLP-1 and ghrelin. RESULTS: During the infusion of exogenous GLP-1 and placebo, GLP-1 plasma concentrations reached steady-state levels of 139+/-15 pmol/l and 12+/-2 pmol/l, respectively (p

  18. Determination of Glucagon-Like Peptide-1, Glucagon and Oxyntomodulin in Plasma

    DEFF Research Database (Denmark)

    Bak, Monika Judyta

    Glucagon-like peptide-1, glucagon and oxyntomodulin are three peptide hormones which play a significant role in diabetes, however there is a major controversy regarding their exact roles due to difficulties in measuring of these peptides because of molecular heterogeneity, low circulating concent...... of the studies from the literature that have provided reliable measurements and thereby help resolve controversies regarding the metabolic roles of the peptides. The improved technology should also provide better reliability of future publications in the field......., the addition of aprotinin to plasma prior to glucagon sample analysis was investigated. Aprotinin addition has been recommended for many years to avoid peptide degradation during sampling and storage. To make sure that the analysed samples are handled correctly and that the peptides are not degraded, a study...

  19. Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

    International Nuclear Information System (INIS)

    Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika

    2007-01-01

    HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1 IIIB infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent

  20. Cationic PEGylated liposomes incorporating an antimicrobial peptide tilapia hepcidin 2-3: an adjuvant of epirubicin to overcome multidrug resistance in cervical cancer cells.

    Science.gov (United States)

    Juang, Vivian; Lee, Hsin-Pin; Lin, Anya Maan-Yuh; Lo, Yu-Li

    Antimicrobial peptides (AMPs) have been recently evaluated as a new generation of adjuvants in cancer chemotherapy. In this study, we designed PEGylated liposomes encapsulating epirubicin as an antineoplastic agent and tilapia hepcidin 2-3, an AMP, as a multidrug resistance (MDR) transporter suppressor and an apoptosis/autophagy modulator in human cervical cancer HeLa cells. Cotreatment of HeLa cells with PEGylated liposomal formulation of epirubicin and hepcidin 2-3 significantly increased the cytotoxicity of epirubicin. The liposomal formulations of epirubicin and/or hepcidin 2-3 were found to noticeably escalate the intracellular H 2 O 2 and O 2 - levels of cancer cells. Furthermore, these treatments considerably reduced the mRNA expressions of MDR protein 1, MDR-associated protein (MRP) 1, and MRP2. The addition of hepcidin 2-3 in liposomes was shown to markedly enhance the intracellular epirubicin uptake and mainly localized into the nucleus. Moreover, this formulation was also found to trigger apoptosis and autophagy in HeLa cells, as validated by significant increases in the expressions of cleaved poly ADP ribose polymerase, caspase-3, caspase-9, and light chain 3 (LC3)-II, as well as a decrease in mitochondrial membrane potential. The apoptosis induction was also confirmed by the rise in sub-G1 phase of cell cycle assay and apoptosis percentage of annexin V/propidium iodide assay. We found that liposomal epirubicin and hepcidin 2-3 augmented the accumulation of GFP-LC3 puncta as amplified by chloroquine, implying the involvement of autophagy. Interestingly, the partial inhibition of necroptosis and the epithelial-mesenchymal transition by this combination was also verified. Altogether, our results provide evidence that coincubation with PEGylated liposomes of hepcidin 2-3 and epirubicin caused programmed cell death in cervical cancer cells through modulation of multiple signaling pathways, including MDR transporters, apoptosis, autophagy, and/or necroptosis

  1. Appetite-related peptides in childhood and adolescence: role of ghrelin, PYY, and GLP-1.

    Science.gov (United States)

    Horner, Katy; Lee, SoJung

    2015-11-01

    During childhood and adolescence, a number of factors, including age, puberty, sex, race, and body composition, may contribute to differences in satiety, food intake, and appetite-related peptides. These peptides include the orexigenic peptide ghrelin and anorexigenic gut peptides peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). For example, lower fasting ghrelin levels, lower postprandial ghrelin suppression, and blunted PYY and GLP-1 responses to food intake could contribute to a dysregulation of appetite in already obese children and adolescents. Whereas, changes in these peptides observed during puberty could facilitate growth. A greater understanding of the major moderating factors of appetite-related peptides in the pediatric population is essential to improve interpretation of study findings and for effective tailoring of strategies targeting appetite control to individuals. While more studies are needed, there is some evidence to suggest that exercise-based lifestyle interventions could be a potential therapeutic strategy to improve appetite-peptide profiles in overweight and obese children and adolescents. The aim of this review is (i) to discuss the potential moderating factors of ghrelin, PYY, and GLP-1, including age and puberty, sex, race and body composition; and (ii) to examine the effects of exercise interventions on these appetite-related gut peptides in children and adolescents.

  2. Mutations in domain II of 23 S rRNA facilitate translation of a 23 S rRNA-encoded pentapeptide conferring erythromycin resistance

    DEFF Research Database (Denmark)

    Dam, M; Douthwaite, S; Tenson, T

    1996-01-01

    Mutations in domain II of Escherichia coli 23 S rRNA that cause resistance to erythromycin do so in a manner fundamentally different from mutations at the drug binding site in domain V of the 23 S rRNA. The domain II mutations are located in a hairpin structure between nucleotides 1198 and 1247...... this hypothesis, a range of point mutations was generated in domain II of 23 S rRNA in the vicinity of the E-peptide open reading frame. We find a correlation between erythromycin resistance of the mutant clones and increased accessibility of the ribosome binding site of the E-peptide gene. Furthermore......, the erythromycin resistance determinant in the mutants was shown to be confined to a small 23 S rRNA segment containing the coding region and the ribosome binding site of the E-peptide open reading frame. It thus appears that the domain II mutations mediate erythromycin resistance by increasing expression...

  3. Membrane selectivity and disordering mechanism of antimicrobial peptide protegrin-1

    Science.gov (United States)

    Ishitsuka, Yuji

    Protegrin-1 (PG-1) is a beta-sheet antimicrobial peptide (AMP), a class of peptides innate to various organisms and functions as a defense agent against harmful microorganisms by means of membrane disordering. Characteristic chemical and structural properties of AMPs allow selective interaction against invaders' cell membranes. Despite their enormous biomedical potential, progress towards developing them into therapeutic agents has been hampered by a lack of insight into their mechanism of action. AMP insertion assays using Langmuir monolayers reveal that both electrostatic properties of the lipid head group as well as the packing density of the lipid tail group play important roles in determining the membrane selectivity of AMPs. These results help elucidate how the AMP selectively targets the cell membrane of microorganisms over the cell membrane of the host. In addition, these results also explain the higher hemolytic ability of PG-1 against human red blood cells (RBCs) compared to the hemolytic ability of PG-1 against sheep and pig RBCs. Synchrotron X-ray reflectivity shows that PG-1 penetrates into the lipid layer. Grazing incidence X-ray diffraction and fluorescence microscopy indicate that the insertion of PG-1 disorders tail group packing. Membrane selectivity and insertion location information of AMPs with different primary sequence and secondary structure have been obtained by using a truncated version of PG-1: PC-17, and an alpha-helical AMP, LL-37, respectively. The similarity of the membrane disordering process across these various peptides motivated us to test the membrane disordering effect of molecules designed to mimic these peptides. Peptide-mimics based on meta-phenylene ethynylenes demonstrate similar membrane disordering effects, showing that the potency of AMPs is derived from their overall chemical and structural properties, rather than exact peptide sequence. Atomic force microscopy (AFM) was used to directly image first, the PG-1

  4. Structural Study of a New HIV-1 Entry Inhibitor and Interaction with the HIV-1 Fusion Peptide in Dodecylphosphocholine Micelles.

    Science.gov (United States)

    Pérez, Yolanda; Gómara, Maria José; Yuste, Eloísa; Gómez-Gutierrez, Patricia; Pérez, Juan Jesús; Haro, Isabel

    2017-08-25

    Previous studies support the hypothesis that the envelope GB virus C (GBV-C) E1 protein interferes the HIV-1 entry and that a peptide, derived from the region 139-156 of this protein, has been defined as a novel HIV-1 entry inhibitor. In this work, we firstly focus on the characterization of the structural features of this peptide, which are determinant for its anti-HIV-1 activity and secondly, on the study of its interaction with the proposed viral target (i.e., the HIV-1 fusion peptide). We report the structure of the peptide determined by NMR spectroscopy in dodecylphosphocholine (DPC) micelles solved by using restrained molecular dynamics calculations. The acquisition of different NMR experiments in DPC micelles (i.e., peptide-peptide titration, diffusion NMR spectroscopy, and addition of paramagnetic relaxation agents) allows a proposal of an inhibition mechanism. We conclude that a 18-mer peptide from the non-pathogenic E1 GBV-C protein, with a helix-turn-helix structure inhibits HIV-1 by binding to the HIV-1 fusion peptide at the membrane level, thereby interfering with those domains in the HIV-1, which are critical for stabilizing the six-helix bundle formation in a membranous environment. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Título do sítio electrónico: Fédération Européenne des Associations Nacionales Travaillant avec les Sans-Abri e European Observatory on Homelessness

    Directory of Open Access Journals (Sweden)

    João Aldeia

    2012-10-01

    Full Text Available Optou-se por apresentar conjuntamente as duas páginas pela sua estreita articulação temática e institucional. Criada em 1989, a FEANTSA – Fédération Européenne des Associations Nacionales Travaillant avec les Sans-Abri – é uma organização não-governamental (ONG dedicada a eliminar a pobreza e exclusão social de indivíduos sem-abrigo ou em risco de conhecer esta situação, que congrega mais de 100 ONGs locais e nacionais de vários Estados-membros da União Europeia, sendo financiada pela Comiss...

  6. Dendroaspis natriuretic peptide binds to the natriuretic peptide clearance receptor

    International Nuclear Information System (INIS)

    Johns, Douglas G.; Ao, Zhaohui; Heidrich, Bradley J.; Hunsberger, Gerald E.; Graham, Taylor; Payne, Lisa; Elshourbagy, Nabil; Lu, Quinn; Aiyar, Nambi; Douglas, Stephen A.

    2007-01-01

    Dendroaspis natriuretic peptide (DNP) is a newly-described natriuretic peptide which lowers blood pressure via vasodilation. The natriuretic peptide clearance receptor (NPR-C) removes natriuretic peptides from the circulation, but whether DNP interacts with human NPR-C directly is unknown. The purpose of this study was to test the hypothesis that DNP binds to NPR-C. ANP, BNP, CNP, and the NPR-C ligands AP-811 and cANP(4-23) displaced [ 125 I]-ANP from NPR-C with pM-to-nM K i values. DNP displaced [ 125 I]-ANP from NPR-C with nM potency, which represents the first direct demonstration of binding of DNP to human NPR-C. DNP showed high pM affinity for the GC-A receptor and no affinity for GC-B (K i > 1000 nM). DNP was nearly 10-fold more potent than ANP at stimulating cGMP production in GC-A expressing cells. Blockade of NPR-C might represent a novel therapeutic approach in augmenting the known beneficial actions of DNP in cardiovascular diseases such as hypertension and heart failure

  7. SPAK Dependent Regulation of Peptide Transporters PEPT1 and PEPT2

    Directory of Open Access Journals (Sweden)

    Jamshed Warsi

    2014-10-01

    Full Text Available Background/Aims: SPAK (STE20-related proline/alanine-rich kinase is a powerful regulator of renal tubular ion transport and blood pressure. Moreover, SPAK contributes to the regulation of cell volume. Little is known, however, about a role of SPAK in the regulation or organic solutes. The present study thus addressed the influence of SPAK on the peptide transporters PEPT1 and PEPT2. Methods: To this end, cRNA encoding PEPT1 or PEPT2 were injected into Xenopus laevis oocytes without or with additional injection of cRNA encoding wild-type, SPAK, WNK1 insensitive inactive T233ASPAK, constitutively active T233ESPAK, and catalytically inactive D212ASPAK. Electrogenic peptide (glycine-glycine transport was determined by dual electrode voltage clamp and PEPT2 protein abundance in the cell membrane by chemiluminescence. Intestinal electrogenic peptide transport was estimated from peptide induced current in Ussing chamber experiments of jejunal segments isolated from gene targeted mice expressing SPAK resistant to WNK-dependent activation (spaktg/tg and respective wild-type mice (spak+/+. Results: In PEPT1 and in PEPT2 expressing oocytes, but not in oocytes injected with water, the dipeptide gly-gly (2 mM generated an inward current, which was significantly decreased following coexpression of SPAK. The effect of SPAK on PEPT1 was mimicked by T233ESPAK, but not by D212ASPAK or T233ASPAK. SPAK decreased maximal peptide induced current of PEPT1. Moreover, SPAK decreased carrier protein abundance in the cell membrane of PEPT2 expressing oocytes. In intestinal segments gly-gly generated a current, which was significantly higher in spaktg/tg than in spak+/+ mice. Conclusion: SPAK is a powerful regulator of peptide transporters PEPT1 and PEPT2.

  8. Coffee, hunger, and peptide YY.

    Science.gov (United States)

    Greenberg, James A; Geliebter, Allan

    2012-06-01

    There is evidence from several empirical studies suggesting that coffee may help people control body weight. Our objective was to assess the effects of caffeine, caffeinated coffee, and decaffeinated coffee, both alone and in combination with 75 g of glucose, on perceived hunger and satiety and related peptides. We conducted a placebo-controlled single-blinded randomized 4-way crossover trial. Eleven healthy male volunteers (mean age, 23.5 ± 5.7 years; mean BMI, 23.6 ± 4.2 kg/m(2)) ingested 1 of 3 test beverages (caffeine in water, caffeinated coffee, or decaffeinated coffee) or placebo (water), and 60 minutes later they ingested the glucose. Eight times during each laboratory visit, hunger and satiety were assessed by visual analog scales, and blood samples were drawn to measure 3 endogenous peptides associated with hunger and satiety: ghrelin, peptide YY (PYY), and leptin. Compared to placebo, decaffeinated coffee yielded significantly lower hunger during the whole 180-minute study period and higher plasma PYY for the first 90 minutes (p hunger or PYY. Caffeinated coffee showed a pattern between that of decaffeinated coffee and caffeine in water. These findings suggest that one or more noncaffeine ingredients in coffee may have the potential to decrease body weight. Glucose ingestion did not change the effects of the beverages. Our randomized human trial showed that decaffeinated coffee can acutely decrease hunger and increase the satiety hormone PYY.

  9. Yield improvement of heterologous peptides expressed in yps1-disrupted Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Egel-Mitani; Andersen; Diers; Hach; Thim; Hastrup; Vad

    2000-06-01

    Heterologous protein expression levels in Saccharomyces cerevisiae fermentations are highly dependent on the susceptibility to endogenous yeast proteases. Small peptides, such as glucagon and glucagon-like-peptides (GLP-1 and GLP-2), featuring an open structure are particularly accessible for proteolytic degradation during fermentation. Therefore, homogeneous products cannot be obtained. The most sensitive residues are found at basic amino acid residues in the peptide sequence. These heterologous peptides are degraded mainly by the YPS1-encoded aspartic protease, yapsin1, when produced in the yeast. In this article, distinct degradation products were analyzed by HPLC and mass spectrometry, and high yield of the heterologous peptide production has been achieved by the disruption of the YPS1 gene (previously called YAP3). By this technique, high yield continuous fermentation of glucagon in S. cerevisiae is now possible.

  10. Paramyxovirus F1 protein has two fusion peptides: implications for the mechanism of membrane fusion.

    Science.gov (United States)

    Peisajovich, S G; Samuel, O; Shai, Y

    2000-03-10

    Viral fusion proteins contain a highly hydrophobic segment, named the fusion peptide, which is thought to be responsible for the merging of the cellular and viral membranes. Paramyxoviruses are believed to contain a single fusion peptide at the N terminus of the F1 protein. However, here we identified an additional internal segment in the Sendai virus F1 protein (amino acids 214-226) highly homologous to the fusion peptides of HIV-1 and RSV. A synthetic peptide, which includes this region, was found to induce membrane fusion of large unilamellar vesicles, at concentrations where the known N-terminal fusion peptide is not effective. A scrambled peptide as well as several peptides from other regions of the F1 protein, which strongly bind to membranes, are not fusogenic. The functional and structural characterization of this active segment suggest that the F1 protein has an additional internal fusion peptide that could participate in the actual fusion event. The presence of homologous regions in other members of the same family suggests that the concerted action of two fusion peptides, one N-terminal and the other internal, is a general feature of paramyxoviruses. Copyright 2000 Academic Press.

  11. Plasma glucagon-like peptide 1 and peptide YY levels are not altered in symptomatic fructose-sorbitol malabsorption

    DEFF Research Database (Denmark)

    Valeur, Jørgen; Øines, Eliann; Morken, Mette Helvik

    2008-01-01

    consecutive patients with functional abdominal complaints, referred to our clinic for investigation of self-reported food hypersensitivity, were included in the study and compared with 15 healthy volunteers. All subjects ingested a mixture of 25 g fructose and 5 g sorbitol. Pulmonary hydrogen and methane...... excretion and plasma glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) levels were measured during the next 3 h. Both habitual and post-test symptoms were assessed. RESULTS: Malabsorption of fructose and sorbitol was present in 61% of the patients and 73% of the controls. Nevertheless, the patients...

  12. Suppression of gastric cancer dissemination by ephrin-B1-derived peptide.

    Science.gov (United States)

    Tanaka, Masamitsu; Kamata, Reiko; Yanagihara, Kazuyoshi; Sakai, Ryuichi

    2010-01-01

    Interaction of the Eph family of receptor protein tyrosine kinases and their ligands, ephrin family members, induces bidirectional signaling through cell-cell contacts. High expression of B-type ephrin is associated with high invasion potential of tumors, and we previously observed that signaling through the C-terminus of ephrin-B1 mediates the migration and invasion of cells, and is involved in the promotion of carcinomatous peritonitis in vivo. Here we show that the intracellular introduction of a synthetic peptide derived from ephrin-B1 C-terminus blocks ephrin-B1 mediated signaling in scirrhous gastric cancer cells. Treatment of cancer cells with a fusion peptide consisting of HIV-TAT and amino acids 331-346 of ephrin-B1 (PTD-EFNB1-C) suppressed the activation of RhoA, mediated by the association of ephrin-B1 with an adaptor protein Dishevelled, and also inhibited extracellular secretion of metalloproteinase. Moreover, injection of PTD-EFNB1-C peptide into the peritoneal cavity of nude mice suppressed carcinomatous peritonitis of intraperitoneally transplanted scirrhous gastric cancer cells. These results indicate the possible application of ephrin-B1 C-terminal peptide to develop novel protein therapy for scirrhous gastric carcinoma, especially in the stage of tumor progression, including peritoneal dissemination.

  13. Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.

    Science.gov (United States)

    Mohd-Radzman, Nadiatul A; Binos, Steve; Truong, Thy T; Imin, Nijat; Mariani, Michael; Djordjevic, Michael A

    2015-08-01

    Small, post-translationally modified and secreted peptides regulate diverse plant developmental processes. Due to low natural abundance, it is difficult to isolate and identify these peptides. Using an improved peptide isolation protocol and Orbitrap mass spectrometry, nine 15-amino-acid CEP peptides were identified that corresponded to the two domains encoded by Medicago truncatula CEP1 (MtCEP1). Novel arabinosylated and hydroxylated peptides were identified in root cultures overexpressing MtCEP1. The five most abundant CEP peptides were hydroxylated and these species were detected also in low amounts in vector control samples. Synthetic peptides with different hydroxylation patterns differentially affected root development. Notably, the domain 1 peptide hydroxylated at Pro4 and Pro11 (D1:HyP4,11) imparted the strongest inhibition of lateral root emergence when grown with 5mM KNO3 and stimulated the highest increase in nodule number when grown with 0mM KNO3. Inhibition of lateral root emergence by D1:HyP4,11 was not alleviated by removing peptide exposure. In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III-IV lateral root primordium numbers by 6-fold (P emerge. Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence. Both peptides increased and altered the root staining pattern of the auxin-responsive reporter GH3:GUS suggesting CEPs alter auxin sensitivity or distribution. The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Individually timing high-protein preloads has no effect on daily energy intake, peptide YY and glucagon-like peptide-1.

    Science.gov (United States)

    Willbond, S M; Doucet, É

    2011-01-01

    Gut hormones have been shown to influence energy intake (EI). To our knowledge, no study has investigated the effects of dietary patterns aimed at optimizing fullness on EI, appetite and gut hormones. To determine whether individually timing high-protein preloads would impact EI, appetite, and peptide YY and glucagon-like peptide-1 (GLP-1) levels. Ten men (body mass index = 25.5 ± 2.6 kg/m(2)) participated in a randomized crossover trial. The three conditions consisted of the self-selection of snacks (condition 1), or the consumption of a preload (300 kcal: 40% protein, 40% carbohydrates and 20% fat) at either 15 min (condition 2) or ∼ 50 min (individually set) (condition 3) before lunch and dinner. During each condition, a standardized breakfast was served, whereas lunch and dinner were self-selected from a five-item menu, and eaten ad libitum. Mealtime and daily EI were measured. Appetite, peptide YY and GLP-1 were sampled over 9 h. No differences in daily EI were noted across conditions (1 = 3078 ± 720 kcal; 2 = 2929 ± 264 kcal; 3 = 2998 ± 437 kcal; not significant). For the most part, daily profiles as well as premeal levels of peptide YY and GLP-1 were not different between conditions. Desire to eat, hunger and prospective food consumption were found to be lowest during condition 1 (P daily EI in healthy human subjects.

  15. Identification of a peptide inhibitor for the histone methyltransferase WHSC1.

    Directory of Open Access Journals (Sweden)

    Michael J Morrison

    Full Text Available WHSC1 is a histone methyltransferase that is responsible for mono- and dimethylation of lysine 36 on histone H3 and has been implicated as a driver in a variety of hematological and solid tumors. Currently, there is a complete lack of validated chemical matter for this important drug discovery target. Herein we report on the first fully validated WHSC1 inhibitor, PTD2, a norleucine-containing peptide derived from the histone H4 sequence. This peptide exhibits micromolar affinity towards WHSC1 in biochemical and biophysical assays. Furthermore, a crystal structure was solved with the peptide in complex with SAM and the SET domain of WHSC1L1. This inhibitor is an important first step in creating potent, selective WHSC1 tool compounds for the purposes of understanding the complex biology in relation to human disease.

  16. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    Science.gov (United States)

    2017-11-01

    cellular proliferation, differentiation, apoptosis, organ development, and sex determination , the protein is processed by the proteasome and the derived...peptide). Vaccine:  2/3 CD8+  4/8 CD4+ Control:  0/4 CD8+  1/8 CD4+ Injection site reactions were common, mild, and self -limited...the ASCO Annual Meeting 2016. 3 Abstract Purpose: Determine the 1-year progression-free survival (PFS) among patients with malignant pleural

  17. The interplay of T1- and T2-relaxation on T1-weighted MRI of hMSCs induced by Gd-DOTA-peptides.

    Science.gov (United States)

    Cao, Limin; Li, Binbin; Yi, Peiwei; Zhang, Hailu; Dai, Jianwu; Tan, Bo; Deng, Zongwu

    2014-04-01

    Three Gd-DOTA-peptide complexes with different peptide sequence are synthesized and used as T1 contrast agent to label human mesenchymal stem cells (hMSCs) for magnetic resonance imaging study. The peptides include a universal cell penetrating peptide TAT, a linear MSC-specific peptide EM7, and a cyclic MSC-specific peptide CC9. A significant difference in labeling efficacy is observed between the Gd-DOTA-peptides as well as a control Dotarem. All Gd-DOTA-peptides as well as Dotarem induce significant increase in T1 relaxation rate which is in favor of T1-weighted MR imaging. Gd-DOTA-CC9 yields the maximum labeling efficacy but poor T1 contrast enhancement. Gd-DOTA-EM7 yields the minimum labeling efficacy but better T1 contrast enhancement. Gd-DOTA-TAT yields a similar labeling efficacy as Gd-DOTA-CC9 and similar T1 contrast enhancement as Gd-DOTA-EM7. The underlying mechanism that governs T1 contrast enhancement effect is discussed. Our results suggest that T1 contrast enhancement induced by Gd-DOTA-peptides depends not only on the introduced cellular Gd content, but more importantly on the effect that Gd-DOTA-peptides exert on the T1-relaxation and T2-relaxation processes/rates. Both T1 and particularly T2 relaxation rate have to be taken into account to interpret T1 contrast enhancement. In addition, the interpretation has to be based on cellular instead of aqueous longitudinal and transverse relaxivities of Gd-DOTA-peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells.

    Science.gov (United States)

    Oufir, Mouhssin; Bisset, Leslie R; Hoffmann, Stefan R K; Xue, Gongda; Klauser, Stephan; Bergamaschi, Bianca; Gervaix, Alain; Böni, Jürg; Schüpbach, Jörg; Gutte, Bernd

    2011-01-01

    An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  19. Orlistat inhibition of intestinal lipase acutely increases appetite and attenuates postprandial glucagon-like peptide-1-(7-36)-amide-1, cholecystokinin, and peptide YY concentrations

    DEFF Research Database (Denmark)

    Ellrichmann, Mark; Kapelle, Mario; Ritter, Peter R

    2008-01-01

    of Orlistat or placebo. Gastric emptying, gallbladder volume and the plasma levels of CCK, PYY, GLP-1, and ghrelin were determined and appetite sensations were measured using visual analogue scales. RESULTS: Gastric emptying was accelerated by Orlistat administration (P emptying.......0001), whereas appetite and prospective food consumption increased (P gastric and gallbladder emptying and reduces...... whether Orlistat alters the secretion of glucagon-like peptide-1-(7-36)-amide (GLP-1), cholecystokinin (CCK), peptide YY (PYY), and ghrelin as well as postprandial appetite sensations. METHODS: Twenty-five healthy human volunteers were examined with a solid-liquid test meal after the oral administration...

  20. Pregnancy-induced rise in serum C-peptide concentrations in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Rehfeld, Jens F; Pedersen-Bjergaard, Ulrik

    2009-01-01

    OBJECTIVE: The purpose of this study was to investigate whether pregnancy induces increased insulin production as a marker of improved beta-cell function in women with long-term type 1 diabetes. RESEARCH DESIGN AND METHODS: This was a prospective study of 90 consecutive pregnant women with type 1.......85). Multivariate regression analysis revealed a positive association between the absolute increase in C-peptide concentrations during pregnancy and decreased A1C from 8 to 33 weeks (P = 0.003). CONCLUSIONS: A pregnancy-induced increase in C-peptide concentrations in women with long-term type 1 diabetes...... in 35 women. RESULTS: C-peptide concentrations gradually increased throughout pregnancy regardless of serum glucose concentrations in the 90 women with a median duration of diabetes of 17 years (range 1-36 years). Among 35 women with paired recordings of stimulated C-peptide, C-peptide production...

  1. Mutation-based structural modification and dynamics study of amyloid beta peptide (1–42: An in-silico-based analysis to cognize the mechanism of aggregation

    Directory of Open Access Journals (Sweden)

    Pritam Kumar Panda

    2016-03-01

    Full Text Available Alzheimer's disease is the prevalent cause of premature senility, a progressive mental disorder due to degeneration in brain and deposition of amyloid β peptide (1–42, a misfolded protein in the form of aggregation that prevails for a prolonged time and obstructs every aspect of life. One of the primary hallmarks of the neuropathological disease is the accretion of amyloid β peptide in the brain that leads to Alzheimer's disease, but the mechanism is still a mystery. Several investigations have shown that mutations at specific positions have a significant impact in stability of the peptide as predicted from aggregation profiles. Here in our study, we have analyzed the mutations by substituting residues at position A22G, E22G, E22K, E22Q, D23N, L34V and molecular dynamics have been performed to check the deviation in stability and conformation of the peptide. The results validated that the mutations at specific positions lead to instability and the proline substitution at E22P and L34P stalled the aggregation of the peptide. Keywords: Amyloid β peptide, Alzheimer's disease, Aggregation, Mutational analysis, NAMD, UCSF Chimera, Discovery Studio Visualizer

  2. Evaluation of beta-cell secretory capacity using glucagon-like peptide 1

    DEFF Research Database (Denmark)

    Vilsbøll, Tina; Nielsen, Mette Toft; Krarup, T

    2000-01-01

    Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients.......Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients....

  3. Database-Guided Discovery of Potent Peptides to Combat HIV-1 or Superbugs

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2013-05-01

    Full Text Available Antimicrobial peptides (AMPs, small host defense proteins, are indispensable for the protection of multicellular organisms such as plants and animals from infection. The number of AMPs discovered per year increased steadily since the 1980s. Over 2,000 natural AMPs from bacteria, protozoa, fungi, plants, and animals have been registered into the antimicrobial peptide database (APD. The majority of these AMPs (>86% possess 11–50 amino acids with a net charge from 0 to +7 and hydrophobic percentages between 31–70%. This article summarizes peptide discovery on the basis of the APD. The major methods are the linguistic model, database screening, de novo design, and template-based design. Using these methods, we identified various potent peptides against human immunodeficiency virus type 1 (HIV-1 or methicillin-resistant Staphylococcus aureus (MRSA. While the stepwise designed anti-HIV peptide is disulfide-linked and rich in arginines, the ab initio designed anti-MRSA peptide is linear and rich in leucines. Thus, there are different requirements for antiviral and antibacterial peptides, which could kill pathogens via different molecular targets. The biased amino acid composition in the database-designed peptides, or natural peptides such as θ-defensins, requires the use of the improved two-dimensional NMR method for structural determination to avoid the publication of misleading structure and dynamics. In the case of human cathelicidin LL-37, structural determination requires 3D NMR techniques. The high-quality structure of LL-37 provides a solid basis for understanding its interactions with membranes of bacteria and other pathogens. In conclusion, the APD database is a comprehensive platform for storing, classifying, searching, predicting, and designing potent peptides against pathogenic bacteria, viruses, fungi, parasites, and cancer cells.

  4. Stereospecific transport of Tyr-MIF-1 across the blood-brain barrier by peptide transport system-1

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W.A.; Kastin, A.J.; Michals, E.A.; Barrera, C.M. (Veterans Affairs Medical Center, New Orleans, LA (USA))

    1990-10-01

    Previous studies have suggested that peptide transport system-1 (PTS-1), the saturable system that transports Tyr-MIF-1, the enkephalins, and related peptides out of the central nervous system (CNS), exhibits stereospecificity. In the present studies, we showed that {sup 125}I-L-Tyr-MIF-1, but not {sup 131}I-D-Tyr-MIF-1, was cleared from the CNS more rapidly than could be accounted for by nonspecific mechanisms. Such clearance was inhibited by a 1.0 nmol dose of L-Tyr-MIF-1, but not by D-Tyr-MIF-1. Neither L- nor D-Tyr-MIF-1 altered the much lower clearance of I-D-Tyr-MIF-1 from the brain. Radioactivity recovered from the vascular space after the injection of {sup 125}I-Tyr-MIF-1 into the lateral ventricle of the brain eluted by HPLC primarily as intact peptide, demonstrating that most of the Tyr-MIF-1 was not degraded during transport. By contrast, the nonsaturable unidirectional influx of Tyr-MIF-1 into the CNS did not distinguish between the isomers. These studies confirm and extend the observations that Tyr-MIF-1 is transported out of the CNS by a saturable, stereospecific transport system as an intact peptide while the influx into the CNS is by a nonsaturable mechanism that does not distinguish between the isomers.

  5. Helical 1:1 α/Sulfono-γ-AA Heterogeneous Peptides with Antibacterial Activity

    Energy Technology Data Exchange (ETDEWEB)

    She, Fengyu; Nimmagadda, Alekhya; Teng, Peng; Su, Ma; Zuo, Xiaobing; Cai, Jianfeng

    2016-05-09

    As one of the greatest threats facing in 21st century, antibiotic resistance is now a major public health concern. Host-defense peptides (HDPs) offer an alternative approach to combat emerging multidrug-resistant bacteria. It is known that helical HDPs such as magainin 2 and its analogs adopt cationic amphipathic conformations upon interaction with bacterial membranes, leading to membrane disruption and subsequent bacterial cell death. We have previously shown that amphipathic sulfono-γ-AApeptides could mimic magainin 2 and exhibit bactericidal activity. In this article, we demonstrate for the first time that amphipathic helical 1:1 α/sulfono-γ-AA heterogeneous peptides, in which regular amino acids and sulfono-γ-AApeptide building blocks are alternatively present in a 1:1 pattern, display potent antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. Small Angle X-ray Scattering (SAXS) suggests that the lead sequences adopt defined helical structures. The subsequent studies including 2 fluorescence microscopy and time-kill experiments indicate that these hybrid peptides exert antimicrobial activity by mimicking the mechanism of HDPs. Our findings may lead to the development of HDP-mimicking antimicrobial peptidomimetics that combat drug-resistant bacterial pathogens. In addition, our results also demonstrate the effective design of a new class of helical foldamer, which could be employed to interrogate other important biological targets such as protein-protein interactions in the future.

  6. Komodo dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound

    OpenAIRE

    M.C. Chung, Ezra; Dean, Scott N.; Propst, Crystal N.; Bishop, Barney M.; van Hoek, Monique L.

    2017-01-01

    Cationic antimicrobial peptides are multifunctional molecules that have a high potential as therapeutic agents. We have identified a histone H1-derived peptide from the Komodo dragon (Varanus komodoensis), called VK25. Using this peptide as inspiration, we designed a synthetic peptide called DRGN-1. We evaluated the antimicrobial and anti-biofilm activity of both peptides against Pseudomonas aeruginosa and Staphylococcus aureus. DRGN-1, more than VK25, exhibited potent antimicrobial and anti-...

  7. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells

    Directory of Open Access Journals (Sweden)

    Mouhssin Oufir

    2011-01-01

    Full Text Available An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  8. Complete sequences of glucagon-like peptide-1 from human and pig small intestine

    DEFF Research Database (Denmark)

    Orskov, C; Bersani, M; Johnsen, A H

    1989-01-01

    intestine of the proglucagon precursor were determined by pairs of basic amino acid residues flanking the two peptides. Earlier studies have shown that synthetic glucagon-like peptide-1 (GLP-1) synthesized according to the proposed structure (proglucagon 71-108 or because residue 108 is Gly, 72-107 amide......) had no physiological effects, whereas a truncated from of GLP-1, corresponding to proglucagon 78-107 amide, strongly stimulated insulin secretion and depressed glucagon secretion. To determine the amino acid sequence of the naturally occurring peptide we isolated GLP-1 from human small intestine...

  9. MDR1 P-glycoprotein transports endogenous opioid peptides

    NARCIS (Netherlands)

    Oude Elferink, R. P.; Zadina, J.

    2001-01-01

    MDR1 P-glycoprotein is generally regarded as an efflux pump for amphipathic toxic compounds. The question remains, however, whether certain endogenous compounds are also substrates for this transporter. Certain peptides have been shown to interact with MDR1 Pgp as well and we have therefore

  10. Safety, immune and clinical responses in metastatic melanoma patients vaccinated with a long peptide derived from indoleamine 2,3-dioxygenase in combination with ipilimumab

    DEFF Research Database (Denmark)

    Bjørn, Jon; Iversen, Trine Zeeberg; Nitschke, Nikolaj Juul

    2016-01-01

    antibody ipilimumab (ipi). METHODS: Ten patients with metastatic melanoma participated in a phase I first-in-human clinical study assessing safety of combining ipi with a 21-mer synthetic peptide vaccine from IDO denoted IDOlong. Secondary and tertiary end points included vaccine and clinical response......BACKGROUND AIM: Indoleamine 2,3-dioxygenase (IDO) is an emerging new target in cancer therapy that can be targeted with active immunotherapy (e.g. through peptide vaccination). Furthermore, IDO has been identified as a key mechanism underlying resistance to treatment with the checkpoint blocking....... RESULTS: Treatment was generally safe and well tolerated. Vaccine related adverse reactions included grade I and II erythema, oedema and pruritus at the vaccination site, which were manageable with mild topical corticosteroids. One patient developed presumed ipi-induced colitis. It initially responded...

  11. 2,3-trans-3,4-trans-3,4-Dihydroxy-L-proline: An amino acid in toxic peptides of Amanita virosa mushrooms

    Science.gov (United States)

    Buku, A.; Faulstich, H.; Wieland, T.; Dabrowski, J.

    1980-01-01

    Among the four possible stereoisomers of 3,4-dihydroxy-L-proline,2,3-trans-3,4-trans-3,4-dihydroxy-L-proline (IV) had not been found in nature previously. It has now been detected as a component of virotoxins, toxic peptides of Amanita virosa mushrooms. Because periodate failed to effect an oxidative glycol splitting reaction, the two hydroxyl groups in positions 3 and 4 were expected to be in a trans configuration. Furthermore, the formation of a 4-lactone on treatment with acids pointed to the carboxyl group and the hydroxyl group at position 4 being in a cis configuration. These results are in agreement with structure IV only. Final proof for structure IV was given by NMR spectroscopy and direct comparison with the 2,3-cis-3,4-trans-3,4-dihydroxy-L-proline isomer. PMID:16592813

  12. Komodo dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound.

    Science.gov (United States)

    M C Chung, Ezra; Dean, Scott N; Propst, Crystal N; Bishop, Barney M; van Hoek, Monique L

    2017-01-01

    Cationic antimicrobial peptides are multifunctional molecules that have a high potential as therapeutic agents. We have identified a histone H1-derived peptide from the Komodo dragon ( Varanus komodoensis) , called VK25. Using this peptide as inspiration, we designed a synthetic peptide called DRGN-1. We evaluated the antimicrobial and anti-biofilm activity of both peptides against Pseudomonas aeruginosa and Staphylococcus aureus . DRGN-1, more than VK25, exhibited potent antimicrobial and anti-biofilm activity, and permeabilized bacterial membranes. Wound healing was significantly enhanced by DRGN-1 in both uninfected and mixed biofilm ( Pseudomonas aeruginosa and Staphylococcus aureus )-infected murine wounds. In a scratch wound closure assay used to elucidate the wound healing mechanism, the peptide promoted the migration of HEKa keratinocyte cells, which was inhibited by mitomycin C (proliferation inhibitor) and AG1478 (epidermal growth factor receptor inhibitor). DRGN-1 also activated the EGFR-STAT1/3 pathway. Thus, DRGN-1 is a candidate for use as a topical wound treatment. Wound infections are a major concern; made increasingly complicated by the emerging, rapid spread of bacterial resistance. The novel synthetic peptide DRGN-1 (inspired by a peptide identified from Komodo dragon) exhibits pathogen-directed and host-directed activities in promoting the clearance and healing of polymicrobial ( Pseudomonas aeruginosa & Staphylococcus aureus ) biofilm infected wounds. The effectiveness of this peptide cannot be attributed solely to its ability to act upon the bacteria and disrupt the biofilm, but also reflects the peptide's ability to promsote keratinocyte migration. When applied in a murine model, infected wounds treated with DRGN-1 healed significantly faster than did untreated wounds, or wounds treated with other peptides. The host-directed mechanism of action was determined to be via the EGFR-STAT1/3 pathway. The pathogen-directed mechanism of action was

  13. Temporizin and Temporizin-1 Peptides as Novel Candidates for Eliminating Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    André L A Souza

    Full Text Available Tropical diseases caused by parasitic infections continue to cause socioeconomic distress worldwide. Among these, Chagas disease has become a great concern because of globalization. Caused by Trypanosoma cruzi, there is an increasing need to discover new, more effective methods to manage infections that minimize disease onset. Antimicrobial peptides represent a possible solution to this challenge. As effector molecules of the innate immune response against pathogens, they are the first line of defense found in all multi-cellular organisms. In amphibians, temporins are a large family of antimicrobial peptides found in skin secretions. Their functional roles and modes of action present unique properties that indicate possible candidates for therapeutic applications. Here, we investigated the trypanocide activity of temporizin and temporizin-1. Temporizin is an artificial, hybrid peptide containing the N-terminal region of temporin A, the pore-forming region of gramicidin and a C-terminus consisting of alternating leucine and lysine. Temporizin-1 is a modification of temporizin with a reduction in the region responsible for insertion into membranes. Their activities were evaluated in a cell permeabilization assay by flow cytometry, an LDH release assay, electron microscopy, an MTT assay and patch clamp experiments. Both temporizin and temporizin-1 demonstrated toxicity against T. cruzi with temporizin displaying slightly more potency. At concentrations up to 100 μg/ ml, both peptides exhibited low toxicity in J774 cells, a macrophage lineage cell line, and no toxicity was observed in mouse primary peritoneal macrophages. In contrast, the peptides showed some toxicity in rat adenoma GH3 cells and Jurkat human lymphoma cells with temporizin-1 displaying lower toxicity. In summary, a shortened form of the hybrid temporizin peptide, temporizin-1, was efficient at killing T. cruzi and it has low toxicity in wild-type mammalian cells. These data suggest

  14. Diversity in peptide recognition by the SH2 domain of SH2B1.

    Science.gov (United States)

    McKercher, Marissa A; Guan, Xiaoyang; Tan, Zhongping; Wuttke, Deborah S

    2018-02-01

    SH2B1 is a multidomain protein that serves as a key adaptor to regulate numerous cellular events, such as insulin, leptin, and growth hormone signaling pathways. Many of these protein-protein interactions are mediated by the SH2 domain of SH2B1, which recognizes ligands containing a phosphorylated tyrosine (pY), including peptides derived from janus kinase 2, insulin receptor, and insulin receptor substrate-1 and -2. Specificity for the SH2 domain of SH2B1 is conferred in these ligands either by a hydrophobic or an acidic side chain at the +3 position C-terminal to the pY. This specificity for chemically disparate species suggests that SH2B1 relies on distinct thermodynamic or structural mechanisms to bind to peptides. Using binding and structural strategies, we have identified unique thermodynamic signatures for each peptide binding mode, and several SH2B1 residues, including K575 and R578, that play distinct roles in peptide binding. The high-resolution structure of the SH2 domain of SH2B1 further reveals conformationally plastic protein loops that may contribute to the ability of the protein to recognize dissimilar ligands. Together, numerous hydrophobic and electrostatic interactions, in addition to backbone conformational flexibility, permit the recognition of diverse peptides by SH2B1. An understanding of this expanded peptide recognition will allow for the identification of novel physiologically relevant SH2B1/peptide interactions, which can contribute to the design of obesity and diabetes pharmaceuticals to target the ligand-binding interface of SH2B1 with high specificity. © 2017 Wiley Periodicals, Inc.

  15. Antimicrobial Peptide Human Neutrophil Peptide 1 as a Potential Link Between Chronic Inflammation and Ductal Adenocarcinoma of the Pancreas.

    Science.gov (United States)

    Pausch, Thomas; Adolph, Sarah; Felix, Klaus; Bauer, Andrea S; Bergmann, Frank; Werner, Jens; Hartwig, Werner

    Defensins are antimicrobial peptides playing a role in innate immunity, in epithelial cell regeneration, and in carcinogenesis of inflammation-triggered malignancies. We analyzed this role in pancreatic ductal adenocarcinoma (PDAC) in the context of its association with chronic pancreatitis (CP). Human tissue of healthy pancreas, CP, and PDAC was screened for defensins by immunohistochemistry. Defensin α 1 (human neutrophil peptide 1 [HNP-1]) expression was validated using mass spectrometry and microarray analysis. Human neutrophil peptide 1 expression and influences of proinflammatory cytokines (tumor necrosis factor α, interleukin 1β, and interferon γ) were studied in human pancreatic cancer cells (Colo 357, T3M4, PANC-1) and normal human pancreatic duct epithelial cells (HPDE). Accumulation of HNP-1 in malignant pancreatic ductal epithelia was seen. Spectrometry showed increased expression of HNP-1 in CP and even more in PDAC. At RNA level, no significant regulation was found. In cancer cells, HNP-1 expression was significantly higher than in HPDE. Proinflammatory cytokines significantly led to increased HNP-1 levels in culture supernatants and decreased levels in lysates of cancer cells. In HPDE cytokines significantly decreased HNP-1 levels. Inflammatory regulation of HNP-1 in PDAC tissue and cells indicates that HNP-1 may be a link between chronic inflammation and malignant transformation in the pancreas.

  16. 16 CFR 23.1 - Deception (general).

    Science.gov (United States)

    2010-01-01

    ... misrepresent the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character..., distribution, or any other material aspect of an industry product. Note 1 to § 23.1: If, in the sale or..., the identity of the grading system used should be disclosed. Note 2 to § 23.1: To prevent deception...

  17. Identification and Relative Quantification of Bioactive Peptides Sequentially Released during Simulated Gastrointestinal Digestion of Commercial Kefir.

    Science.gov (United States)

    Liu, Yufang; Pischetsrieder, Monika

    2017-03-08

    Health-promoting effects of kefir may be partially caused by bioactive peptides. To evaluate their formation or degradation during gastrointestinal digestion, we monitored changes of the peptide profile in a model of (1) oral, (2) gastric, and (3) small intestinal digestion of kefir. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy analyses revealed clearly different profiles between digests 2/3 and kefir/digest 1. Subsequent ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry identified 92 peptides in total (25, 25, 43, and 30, partly overlapping in kefir and digests 1, 2, and 3, respectively), including 16 peptides with ascribed bioactivity. Relative quantification in scheduled multiple reaction monitoring mode showed that many bioactive peptides were released by simulated digestion. Most prominently, the concentration of angiotensin-converting enzyme inhibitor β-casein 203-209 increased approximately 10 000-fold after combined oral, gastric, and intestinal digestion. Thus, physiological digestive processes may promote bioactive peptide formation from proteins and oligopeptides in kefir. Furthermore, bioactive peptides present in certain compartments of the gastrointestinal tract may exert local physiological effects.

  18. Effect of glycosylation on biodistribution of radiolabeled glucagon-like peptide 1

    International Nuclear Information System (INIS)

    Watanabe, Ayahisa; Nishijima, Ken-ichi; Zhao, Songji; Tamaki, Nagara; Kuge, Yuji; Tanaka, Yoshikazu; Itoh, Takeshi; Takemoto, Hiroshi

    2012-01-01

    Glycosylation is generally applicable as a strategy for increasing the activity of bioactive proteins. In this study, we examined the effect of glycosylation on biodistribution of radiolabeled glucagon-like peptide 1 (GLP-1) as a bioactive peptide for type 2 diabetes. Noninvasive imaging studies were performed using a gamma camera after the intravenous administration of 123 I-GLP-1 or 123 I-α2, 6-sialyl N-acetyllactosamine (glycosylated) GLP-1 in rats. In ex vivo biodistribution studies using 125 I-GLP-1 or 125 I-glycosylated GLP-1, organ samples were measured for radioactivity. Plasma samples were added to 15% trichloroacetic acid (TCA) to obtain TCA-insoluble and TCA-soluble fractions. The radioactivity in the TCA-insoluble and TCA-soluble fractions was measured. In the noninvasive imaging studies, a relatively high accumulation level of 123 I-GLP-1 was found in the liver, which is the major organ to eliminate exogenous GLP-1. The area under the time-activity curve (AUC) of 123 I-glycosylated GLP-1 in the liver was significantly lower (89%) than that of 123 I-GLP-1. These results were consistent with those of ex vivo biodistribution studies using 125 I-labeled peptides. The AUC of 125 I-glycosylated GLP-1 in the TCA-insoluble fraction was significantly higher (1.7-fold) than that of GLP-1. This study demonstrated that glycosylation significantly decreased the distribution of radiolabeled GLP-1 into the liver and increased the concentration of radiolabeled GLP-1 in plasma. These results suggested that glycosylation is a useful strategy for decreasing the distribution into the liver of bioactive peptides as desirable pharmaceuticals. (author)

  19. Glucagon-like peptide 1 receptor agonists: a new approach to type 2 ...

    African Journals Online (AJOL)

    Hypoglycaemia and weight gain that are associated with many antidiabetic medications may interfere with the implementation and long-term application of treatment strategies. Glucose homeostasis is dependent on a complex interplay of multiple hormones and gastrointestinal peptides, including glucagon-like peptide 1 ...

  20. Structural Characterization and Disulfide Assignment of Spider Peptide Phα1β by Mass Spectrometry

    Science.gov (United States)

    Wormwood, Kelly L.; Ngounou Wetie, Armand Gatien; Gomez, Marcus Vinicius; Ju, Yue; Kowalski, Paul; Mihasan, Marius; Darie, Costel C.

    2018-05-01

    Native Phα1β is a peptide purified from the venom of the armed spider Phoneutria nigriventer that has been shown to have an extensive analgesic effect with fewer side effects than ω-conotoxin MVIIA. Recombinant Phα1β mimics the effects of the native Phα1β. Because of this, it has been suggested that Phα1β may have potential to be used as a therapeutic for controlling persistent pathological pain. The amino acid sequence of Phα1β is known; however, the exact structure and disulfide arrangement has yet to be determined. Determination of the disulfide linkages and exact structure could greatly assist in pharmacological analysis and determination of why this peptide is such an effective analgesic. Here, we used biochemical and mass spectrometry approaches to determine the disulfide linkages present in the recombinant Phα1β peptide. Using a combination of MALDI-MS, direct infusion ESI-MS, and nanoLC-MS/MS analysis of the undigested recombinant Phα1β peptide and digested with AspN, trypsin, or AspN/trypsin, we were able to identify and confirm all six disulfide linkages present in the peptide as Cys1-2, Cys3-4, Cys5-6, Cys7-8, Cys9-10, and Cys11-12. These results were also partially confirmed in the native Phα1β peptide. These experiments provide essential structural information about Phα1β and may assist in providing insight into the peptide's analgesic effect with very low side effects. [Figure not available: see fulltext.

  1. Structural Characterization and Disulfide Assignment of Spider Peptide Phα1β by Mass Spectrometry

    Science.gov (United States)

    Wormwood, Kelly L.; Ngounou Wetie, Armand Gatien; Gomez, Marcus Vinicius; Ju, Yue; Kowalski, Paul; Mihasan, Marius; Darie, Costel C.

    2018-04-01

    Native Phα1β is a peptide purified from the venom of the armed spider Phoneutria nigriventer that has been shown to have an extensive analgesic effect with fewer side effects than ω-conotoxin MVIIA. Recombinant Phα1β mimics the effects of the native Phα1β. Because of this, it has been suggested that Phα1β may have potential to be used as a therapeutic for controlling persistent pathological pain. The amino acid sequence of Phα1β is known; however, the exact structure and disulfide arrangement has yet to be determined. Determination of the disulfide linkages and exact structure could greatly assist in pharmacological analysis and determination of why this peptide is such an effective analgesic. Here, we used biochemical and mass spectrometry approaches to determine the disulfide linkages present in the recombinant Phα1β peptide. Using a combination of MALDI-MS, direct infusion ESI-MS, and nanoLC-MS/MS analysis of the undigested recombinant Phα1β peptide and digested with AspN, trypsin, or AspN/trypsin, we were able to identify and confirm all six disulfide linkages present in the peptide as Cys1-2, Cys3-4, Cys5-6, Cys7-8, Cys9-10, and Cys11-12. These results were also partially confirmed in the native Phα1β peptide. These experiments provide essential structural information about Phα1β and may assist in providing insight into the peptide's analgesic effect with very low side effects. [Figure not available: see fulltext.

  2. Evaluation of peptide adsorption-controlled liquid chromatography-tandem mass spectrometric (PAC-LC-MS/MS) method for simple and simultaneous quantitation of amyloid β 1-38, 1-40, 1-42 and 1-43 peptides in dog cerebrospinal fluid.

    Science.gov (United States)

    Goda, Ryoya; Kobayashi, Nobuhiro

    2012-05-01

    To evaluate the usefulness of the peptide adsorption-controlled liquid chromatography-tandem mass spectrometry (PAC-LC-MS/MS) for reproducible measurement of peptides in biological fluids, simultaneous quantitation of amyloid β 1-38, 1-40, 1-42 and 1-43 peptides (Aβ38, Aβ40, Aβ42 and Aβ43) in dog cerebrospinal fluid (CSF) was tried. Each stable isotope labeled Aβ was used as the internal standard to minimize the influence of CSF matrix on the reproducible Aβ quantitation. To reduce a loss of Aβ during the pretreatment procedures, the dog CSF diluted by water-acetic acid-methanol (2:6:1, v/v/v) was loaded on PAC-LC-MS/MS directly. Quantification of the Aβ in the diluted dog CSF was carried out using multiple reaction monitoring (MRM) mode. The [M+5H(5+)] and b(5+) ion fragment of each peptide were chosen as the precursor and product ions for MRM transitions of each peptide. The calibration curves were drawn from Aβ standard calibration solutions using PAC-LC-MS/MS. Analysis of dog CSF samples suggests that the basal concentration of Aβ38, Aβ40, Aβ42 and Aβ43 in dog CSF is approximately 300, 900, 200 and 30 pM, respectively. This is the first time Aβ concentrations in dog CSF have been reported. Additionally, the evaluation of intra- and inter-day reproducibility of analysis of Aβ standard solution, the freeze-thaw stability and the room temperature stability of Aβ standard solution suggest that the PAC-LC-MS/MS method enables reproducible Aβ quantitation. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Unique and cross-reactive T cell epitope peptides of the major Bahia grass pollen allergen, Pas n 1.

    Science.gov (United States)

    Etto, Tamara; de Boer, Carmela; Prickett, Sara; Gardner, Leanne M; Voskamp, Astrid; Davies, Janet M; O'Hehir, Robyn E; Rolland, Jennifer M

    2012-01-01

    Bahia grass pollen (BaGP) is a major cause of allergic rhinitis. Subcutaneous allergen-specific immunotherapy is effective for grass pollen allergy, but is unsuitable for patients with moderate to severe asthma due to the risk of anaphylaxis. T cell-reactive but IgE nonreactive peptides provide a safer treatment option. This study aimed to identify and characterize dominant CD4(+) T cell epitope peptides of the major BaGP allergen, Pas n 1. Pas n 1-specific T cell lines generated from the peripheral blood of BaGP-allergic subjects were tested for proliferative and cytokine response to overlapping 20-mer Pas n 1 peptides. Cross-reactivity to homologous peptides from Lol p 1 and Cyn d 1 of Ryegrass and Bermuda grass pollen, respectively, was assessed using Pas n 1 peptide-specific T cell clones. MHC class II restriction of Pas n 1 peptide T cell recognition was determined by HLA blocking assays and peptide IgE reactivity tested by dot blotting. Three Pas n 1 peptides showed dominant T cell reactivity; 15 of 18 (83%) patients responded to one or more of these peptides. T cell clones specific for dominant Pas n 1 peptides showed evidence of species-specific T cell reactivity as well as cross-reactivity with other group 1 grass pollen allergens. The dominant Pas n 1 T cell epitope peptides showed HLA binding diversity and were non-IgE reactive. The immunodominant T cell-reactive Pas n 1 peptides are candidates for safe immunotherapy for individuals, including those with asthma, who are allergic to Bahia and possibly other grass pollens. Copyright © 2012 S. Karger AG, Basel.

  4. Biophysical characterization of Vpu from HIV-1 suggests a channel-pore dualism.

    Science.gov (United States)

    Mehnert, T; Routh, A; Judge, P J; Lam, Y H; Fischer, D; Watts, A; Fischer, W B

    2008-03-01

    Vpu from HIV-1 is an 81 amino acid type I integral membrane protein which consists of a cytoplasmic and a transmembrane (TM) domain. The TM domain is known to alter membrane permeability for ions and substrates when inserted into artificial membranes. Peptides corresponding to the TM domain of Vpu (Vpu(1-32)) and mutant peptides (Vpu(1-32)-W23L, Vpu(1-32)-R31V, Vpu(1-32)-S24L) have been synthesized and reconstituted into artificial lipid bilayers. All peptides show channel activity with a main conductance level of around 20 pS. Vpu(1-32)-W23L has a considerable flickering pattern in the recordings and longer open times than Vpu(1-32). Whilst recordings for Vpu(1-32)-R31V are almost indistinguishable from those of the WT peptide, recordings for Vpu(1-32)-S24L do not exhibit any noticeable channel activity. Recordings of WT peptide and Vpu(1-32)-W23L indicate Michaelis-Menten behavior when the salt concentration is increased. Both peptide channels follow the Eisenman series I, indicative for a weak ion channel with almost pore like characteristics. 2007 Wiley-Liss, Inc.

  5. Mitochondria targeted peptides protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity.

    Science.gov (United States)

    Yang, Lichuan; Zhao, Kesheng; Calingasan, Noel Y; Luo, Guoxiong; Szeto, Hazel H; Beal, M Flint

    2009-09-01

    A large body of evidence suggests that mitochondrial dysfunction and oxidative damage play a role in the pathogenesis of Parkinson's disease (PD). A number of antioxidants have been effective in animal models of PD. We have developed a family of mitochondria-targeted peptides that can protect against mitochondrial swelling and apoptosis (SS peptides). In this study, we examined the ability of two peptides, SS-31 and SS-20, to protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in mice. SS-31 produced dose-dependent complete protection against loss of dopamine and its metabolites in striatum, as well as loss of tyrosine hydroxylase immunoreactive neurons in substantia nigra pars compacta. SS-20, which does not possess intrinsic ability in scavenging reactive oxygen species, also demonstrated significant neuroprotective effects on dopaminergic neurons of MPTP-treated mice. Both SS-31 and SS-20 were very potent (nM) in preventing MPP+ (1-methyl-4-phenylpyridinium)-induced cell death in cultured dopamine cells (SN4741). Studies with isolated mitochondria showed that both SS-31 and SS-20 prevented MPP+-induced inhibition of oxygen consumption and ATP production, and mitochondrial swelling. These findings provide strong evidence that these neuroprotective peptides, which target both mitochondrial dysfunction and oxidative damage, are a promising approach for the treatment of PD.

  6. Treatment of Experimental Brain Tumors with Trombospondin-1 Derived Peptides: an In Vivo Imaging Study

    Directory of Open Access Journals (Sweden)

    A. Bogdanov, Jr.

    1999-11-01

    Full Text Available Antiangiogenic and antiproliferative effects of synthetic D-reverse peptides derived from the type 1 repeats of thrombospondin (TSP1 [1,2] were studied in rodent C6 glioma and 9L gliosarcomas. To directly measure tumor size and vascular parameters, we employed in vivo magnetic resonance (MR imaging and corroborated results by traditional morphometric tissue analysis. Rats bearing either C6 or 9L tumors were treated with TSP1-derived peptide (D-reverse amKRFKQDGGWSHWSPWSSac, n=13 or a control peptide (D-reverse am KRAKQAGGASHASPASSac, n=12 at 10 mg/kg, administered either intravenously or through subcutaneous miniosmotic pumps starting 10 days after tumor implantation. Eleven days later, the effect of peptide treatment was evaluated. TSP1 peptide-treated 9L tumors (50.7±44.2 mm3, n=7 and C6 tumors (41.3±34.2 mm3, n=6 were significantly smaller than tumors treated with control peptide (9L: 215.7±67.8 mm3, n=6; C6:184.2±105.2 mm3, n=6. In contrast, the in vivo vascular volume fraction, the mean vascular area (determined by microscopy, and the microvascular density of tumors were not significantly different in any of the experimental groups. In cell culture, TSP1, and the amKRFKQDGGWSHWSPWSSac peptide showed antiproliferative effects against C6 with an IC of 45 nM for TSP1. These results indicate that TSP1derived peptides retard brain tumor growth presumably as a result of slower de novo blood vessel formation and synergistic direct antiproliferative effects on tumor cells. We also show that in vivo MR imaging can be used to assess treatment efficacy of novel antiangiogenic drugs non-invasively, which has obvious implications for clinical trials.

  7. The secreted peptide PIP1 amplifies immunity through receptor-like kinase 7.

    Directory of Open Access Journals (Sweden)

    Shuguo Hou

    2014-09-01

    Full Text Available In plants, innate immune responses are initiated by plasma membrane-located pattern recognition receptors (PRRs upon recognition of elicitors, including exogenous pathogen-associated molecular patterns (PAMPs and endogenous damage-associated molecular patterns (DAMPs. Arabidopsis thaliana produces more than 1000 secreted peptide candidates, but it has yet to be established whether any of these act as elicitors. Here we identified an A. thaliana gene family encoding precursors of PAMP-induced secreted peptides (prePIPs through an in-silico approach. The expression of some members of the family, including prePIP1 and prePIP2, is induced by a variety of pathogens and elicitors. Subcellular localization and proteolytic processing analyses demonstrated that the prePIP1 product is secreted into extracellular spaces where it is cleaved at the C-terminus. Overexpression of prePIP1 and prePIP2, or exogenous application of PIP1 and PIP2 synthetic peptides corresponding to the C-terminal conserved regions in prePIP1 and prePIP2, enhanced immune responses and pathogen resistance in A. thaliana. Genetic and biochemical analyses suggested that the receptor-like kinase 7 (RLK7 functions as a receptor of PIP1. Once perceived by RLK7, PIP1 initiates overlapping and distinct immune signaling responses together with the DAMP PEP1. PIP1 and PEP1 cooperate in amplifying the immune responses triggered by the PAMP flagellin. Collectively, these studies provide significant insights into immune modulation by Arabidopsis endogenous secreted peptides.

  8. Flow cytometric analysis of cell killing by the jumper ant venom peptide pilosulin 1.

    Science.gov (United States)

    King, M A; Wu, Q X; Donovan, G R; Baldo, B A

    1998-08-01

    Pilosulin 1 is a synthetic 56-amino acid residue polypeptide that corresponds to the largest allergenic polypeptide found in the venom of the jumper ant Myrmecia pilosula. Initial experiments showed that pilosulin 1 lysed erythrocytes and killed proliferating B cells. Herein, we describe how flow cytometry was used to investigate the cytotoxicity of the peptide for human white blood cells. Cells were labeled with fluorochrome-conjugated antibodies, incubated with the peptide and 7-aminoactinomycin D (7-AAD), and then analyzed. The effects of varying the peptide concentration, serum concentration, incubation time, and incubation temperature were measured, and the cytotoxicity of pilosulin 1 was compared with that of the bee venom peptide melittin. The antibodies and the 7-AAD enabled the identification of cell subpopulations and dead cells, respectively. It was possible, using the appropriate mix of antibodies and four-color analysis, to monitor the killing of three or more cell subpopulations simultaneously. We found that 1) pilosulin 1 killed cells within minutes, with kinetics similar to those of melittin; 2) pilosulin 1 was a slightly more potent cytotoxic agent than melittin; 3) both pilosulin 1 and melittin were more potent against mononuclear leukocytes than against granulocytes; and 4) serum inhibited killing by either peptide.

  9. Evaluation of peptide designing strategy against subunit reassociation in mucin 1: A steered molecular dynamics approach.

    Directory of Open Access Journals (Sweden)

    J Lesitha Jeeva Kumari

    Full Text Available Subunit reassociation in mucin 1, a breast cancer tumor marker, is reported as one of the critical factors for its cytoplasmic activation. Inhibition of its heterodimeric association would therefore result in loss of its function and alter disease progression. The present study aimed at evaluating peptide inhibitor designing strategies that may serve as antagonist against this receptor-ligand alliance. Several peptides and their derivatives were designed based on native residues, subunit interface, hydrogen bonding and secondary structure. Docking studies with the peptides were carried on the receptor subunit and their binding affinities were evaluated using steered molecular dynamics simulation and umbrella sampling. Our results showed that among all the different classes of peptides evaluated, the receptor based peptide showed the highest binding affinity. This result was concurrent with the experimental observation that the receptor-ligand alliance in mucin 1 is highly specific. Our results also show that peptide ligand against this subunit association is only stabilized through native residue inter-protein interaction irrespective of the peptide structure, peptide length and number of hydrogen bonds. Consistency in binding affinity, pull force and free energy barrier was observed with only the receptor derived peptides which resulted in favorable interprotein interactions at the interface. Several observations were made and discussed which will eventually lead to designing efficient peptide inhibitors against mucin 1 heterodimeric subunit reassociation.

  10. Variables associated with persistence of C-Peptide secretion among patients with Type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Ibrahim Abbood Zaboon

    2017-01-01

    Full Text Available Background: C-peptide is a reliable method for estimating the beta-cell residual function. The objective of this study to assess the variables associated with persistence of C-peptide secretion among patients with Type 1 diabetes mellitus (T1DM. Patients and Methods: This was a cross-sectional study conducted from October 2015 to September 2016. This study enrolled patients with T1DM with at least 1 year or more duration. Random C-peptide with concomitant plasma glucose at least 144 mg/dl (8 mmol/l was measured and at this cutoff considered as a stimulated value. Variables that were assessed were age at the time of enrollment, age at the diagnosis of diabetes, gender, family history of diabetes, duration of diabetes, frequency of insulin per day, insulin dose (units/kg/day, type of insulin, devices delivery, body mass index (BMI at enrollment, blood pressure, glucose (plasma, lipid profile, glycated hemoglobin (HbA1c, thyrotropin (TSH, and antibodies to glutamic acid decarboxylase (GAD65, thyroid peroxidase antibodies (anti-TPO, and tissue transglutaminase antibodies-IgA (anti-TTG-IgA. Results: A total 324 patients were included in the study. A higher level of C-peptide has been seen if the disease acquired at the age of 18 years and older with detectable C-peptide observed among 17.7% of those diagnosed at age <18 years versus 31.7% for those aged 18 years or above. The more the duration of diabetes, the more is the loss of C-peptide. On logistic regression analysis, only duration of diabetes <6 years, and insulin dose <1 U/kg/day were statistically significantly associated with the detectable level of C-peptide in this cohort of T1DM. Conclusion: Diagnosis of TIDM at a late age, positive family history of diabetes, those requiring <1 U of insulin per kg per day, and higher fasting glucose was associated with higher and more detectable C-peptide. On multivariable analysis, the only duration of diabetes <6 years and insulin dose <1 U of insulin

  11. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2, wh...

  12. Peptide YY3-36 and glucagon-like peptide-1 in functional dyspepsia. Secretion and role in symptom generation

    DEFF Research Database (Denmark)

    Witte, Anne-Barbara; Hilsted, Linda; Holst, Jens Juul

    2016-01-01

    method. Secondly, participants drank 75 mL (90 kcal) per five min until maximal satiety. PYY3-36, GLP-1, glucose, and insulin concentrations were assessed. Satiety measures and dyspeptic symptoms were registered using visual analogue scales. RESULTS: Gastric emptying, glucose, PYY3-36, and GLP-1......OBJECTIVE: The role of peptide YY3-36 (PYY3-36), glucagon-like peptide-1 (GLP-1), and glucose homoeostasis in symptom development in functional dyspepsia (FD) is unclear. The aim was to investigate postprandial changes in plasma PYY3-36, GLP-1, glucose and insulin, and the relationship between PYY3......-36, GLP-1, dyspeptic symptoms, and satiety measurements. MATERIALS AND METHODS: Thirty-six patients with functional dyspepsia and 18 healthy controls consumed a liquid meal at two occasions. Firstly, a fixed amount of 250 mL (300 kcal) was consumed and gastric emptying was assessed using the paracetamol...

  13. Molecular Pathways for Immune Recognition of Preproinsulin Signal Peptide in Type 1 Diabetes.

    Science.gov (United States)

    Kronenberg-Versteeg, Deborah; Eichmann, Martin; Russell, Mark A; de Ru, Arnoud; Hehn, Beate; Yusuf, Norkhairin; van Veelen, Peter A; Richardson, Sarah J; Morgan, Noel G; Lemberg, Marius K; Peakman, Mark

    2018-04-01

    The signal peptide region of preproinsulin (PPI) contains epitopes targeted by HLA-A-restricted (HLA-A0201, A2402) cytotoxic T cells as part of the pathogenesis of β-cell destruction in type 1 diabetes. We extended the discovery of the PPI epitope to disease-associated HLA-B*1801 and HLA-B*3906 (risk) and HLA-A*1101 and HLA-B*3801 (protective) alleles, revealing that four of six alleles present epitopes derived from the signal peptide region. During cotranslational translocation of PPI, its signal peptide is cleaved and retained within the endoplasmic reticulum (ER) membrane, implying it is processed for immune recognition outside of the canonical proteasome-directed pathway. Using in vitro translocation assays with specific inhibitors and gene knockout in PPI-expressing target cells, we show that PPI signal peptide antigen processing requires signal peptide peptidase (SPP). The intramembrane protease SPP generates cytoplasm-proximal epitopes, which are transporter associated with antigen processing (TAP), ER-luminal epitopes, which are TAP independent, each presented by different HLA class I molecules and N-terminal trimmed by ER aminopeptidase 1 for optimal presentation. In vivo, TAP expression is significantly upregulated and correlated with HLA class I hyperexpression in insulin-containing islets of patients with type 1 diabetes. Thus, PPI signal peptide epitopes are processed by SPP and loaded for HLA-guided immune recognition via pathways that are enhanced during disease pathogenesis. © 2018 by the American Diabetes Association.

  14. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

    Roč. 11, - (2005), 757-788 ISSN 1075-2617 R&D Projects: GA ČR(CZ) GA203/03/1362 Institutional research plan: CEZ:AV0Z40550506 Keywords : multiple antigen peptides * peptide dendrimers * synthetic vaccine * multipleantigenic peptides Subject RIV: CC - Organic Chemistry Impact factor: 1.803, year: 2005

  15. Structure, Content, and Bioactivity of Food-Derived Peptides in the Body.

    Science.gov (United States)

    Sato, Kenji

    2018-03-28

    Orally administered peptides are assumed to be degraded into amino acids in the body. However, our recent studies revealed some food-derived prolyl and pyroglutamyl peptides with 2-3 amino acid residues in the blood of humans and animals, while most of the peptides in the endoproteinase digest of food protein are degraded by exopeptidase. Some food-derived dipeptides in the body display in vitro and in vivo biological activities. These facts indicate that the biological activities of food-derived peptides in the body rather than those in food are crucial to understanding the mechanism of the beneficial effects of orally administered peptides.

  16. Molecular dynamics simulations and in silico peptide ligand screening of the Elk-1 ETS domain

    Directory of Open Access Journals (Sweden)

    Hussain Abrar

    2011-11-01

    Full Text Available Abstract Background The Elk-1 transcription factor is a member of a group of proteins called ternary complex factors, which serve as a paradigm for gene regulation in response to extracellular signals. Its deregulation has been linked to multiple human diseases including the development of tumours. The work herein aims to inform the design of potential peptidomimetic compounds that can inhibit the formation of the Elk-1 dimer, which is key to Elk-1 stability. We have conducted molecular dynamics simulations of the Elk-1 ETS domain followed by virtual screening. Results We show the ETS dimerisation site undergoes conformational reorganisation at the α1β1 loop. Through exhaustive screening of di- and tri-peptide libraries against a collection of ETS domain conformations representing the dynamics of the loop, we identified a series of potential binders for the Elk-1 dimer interface. The di-peptides showed no particular preference toward the binding site; however, the tri-peptides made specific interactions with residues: Glu17, Gln18 and Arg49 that are pivotal to the dimer interface. Conclusions We have shown molecular dynamics simulations can be combined with virtual peptide screening to obtain an exhaustive docking protocol that incorporates dynamic fluctuations in a receptor. Based on our findings, we suggest experimental binding studies to be performed on the 12 SILE ranked tri-peptides as possible compounds for the design of inhibitors of Elk-1 dimerisation. It would also be reasonable to consider the score-ranked tri-peptides as a comparative test to establish whether peptide size is a determinant factor of binding to the ETS domain.

  17. Conformational preferences of a chimeric peptide HIV-1 immunogen from the C4-V3 domains of gp120 envelope protein of HIV-1 CAN0A based on solution NMR: comparison to a related immunogenic peptide from HIV-1 RF.

    Science.gov (United States)

    Vu, H M; de Lorimier, R; Moody, M A; Haynes, B F; Spicer, L D

    1996-04-23

    A critical problem to overcome on HIV vaccine design is the variability among HIV strains. One strategy to solve this problem is the construction of multicomponent immunogens reflective of common HIV motifs. Currently, it is not known if these motifs should be based primarily on amino acid sequence or higher-order structure of the viral proteins of a combination of the two. In this paper, we report NMR-derived solution conformations for a sympathetic peptide taken from the C4 and V3 domains of HIV-1 CAN0A gp120 envelope protein. This peptide, designated T1-SP10CAN0(A), is compared to a recently reported C4-V3 peptide. T1-SP10RF(A) from the HIV-1 RF strain [de Lorimier et al. (1994) Biochemistry 33, 2055-2062], in terms of conformational features and immune responses in mice [Haynes et al. (1995) AIDS Res. Hum. Retroviruses 11, 211-221]. The T1 segment of 16 amino acids from the gp120 C4 domain is identical in both peptides and exhibits nascent helical character. The SP10 region, taken from the gp120 V3 loop, differs from that of T1-SP10RF(A) in both sequence and conformations. A reverse turn is observed at the conserved GPGX sequence. The rest of the Sp10 domain is extended with the exception of the last three residues which show evidence for a helical arrangement. Modeling of the turn region of the T1-SP10CAN0(A) peptide shows exposure of a continuous apolar stretch of side chains similar to that reported in the crystal structure of a V3 peptide from HIV-1 MN complexed with a monoclonal antibody [Rini et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 6325-6329]. this hydrophobic patch is interrupted by a charged Lys residue in the T1-SP10RF(A) peptide. This observation suggests that the HIV-1 CAN0A and HIV-1 RF C4-V3 peptides can induce widely different anti-HIV antibodies. consistent with immunogenic results.

  18. Recognition of HIV-1 peptides by host CTL is related to HIV-1 similarity to human proteins.

    Directory of Open Access Journals (Sweden)

    Morgane Rolland

    Full Text Available BACKGROUND: While human immunodeficiency virus type 1 (HIV-1-specific cytotoxic T lymphocytes preferentially target specific regions of the viral proteome, HIV-1 features that contribute to immune recognition are not well understood. One hypothesis is that similarities between HIV and human proteins influence the host immune response, i.e., resemblance between viral and host peptides could preclude reactivity against certain HIV epitopes. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the extent of similarity between HIV-1 and the human proteome. Proteins from the HIV-1 B consensus sequence from 2001 were dissected into overlapping k-mers, which were then probed against a non-redundant database of the human proteome in order to identify segments of high similarity. We tested the relationship between HIV-1 similarity to host encoded peptides and immune recognition in HIV-infected individuals, and found that HIV immunogenicity could be partially modulated by the sequence similarity to the host proteome. ELISpot responses to peptides spanning the entire viral proteome evaluated in 314 individuals showed a trend indicating an inverse relationship between the similarity to the host proteome and the frequency of recognition. In addition, analysis of responses by a group of 30 HIV-infected individuals against 944 overlapping peptides representing a broad range of individual HIV-1B Nef variants, affirmed that the degree of similarity to the host was significantly lower for peptides with reactive epitopes than for those that were not recognized. CONCLUSIONS/SIGNIFICANCE: Our results suggest that antigenic motifs that are scarcely represented in human proteins might represent more immunogenic CTL targets not selected against in the host. This observation could provide guidance in the design of more effective HIV immunogens, as sequences devoid of host-like features might afford superior immune reactivity.

  19. Glucagon-like peptide-1, glucose homeostasis and diabetes

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Deacon, Carolyn F; Vilsbøll, Tina

    2008-01-01

    Incretins, enhancers of insulin secretion, are essential for glucose tolerance, and a reduction in their function might contribute to poor beta-cell function in patients with type-2 diabetes mellitus. However, at supraphysiological doses, the incretin glucagon-like peptide-1 (GLP-1) protects...... as therapies for type-2 diabetes and have recently reached the market. The pathophysiological basis the clinical use of these therapeutics is reviewed here....

  20. Inducible Expression of the De-Novo Designed Antimicrobial Peptide SP1-1 in Tomato Confers Resistance to Xanthomonas campestris pv. vesicatoria.

    Directory of Open Access Journals (Sweden)

    Areli Herrera Diaz

    Full Text Available Antimicrobial peptides (AMPs are small peptides with less than 50 amino acids and are part of the innate immune response in almost all organisms, including bacteria, vertebrates, invertebrates and plants. AMPs are active against a broad-spectrum of pathogens. The inducible expression of AMPs in plants is a promising approach to combat plant pathogens with minimal negative side effects, such as phytotoxicity or infertility. In this study, inducible expression of the de-novo designed AMP SP1-1 in Micro Tom tomato protected tomato fruits against bacterial spot disease caused by Xanthomonas campestris pv. vesicatoria. The peptide SP1-1 was targeted to the apoplast which is the primary infection site for plant pathogens, by fusing SP1-1 peptide to the signal peptide RsAFP1 of radish (Raphanus sativus. The pathogen inducibility of the expression was enabled by using an optimized inducible 4XW2/4XS promoter. As a result, the tomato fruits of independently generated SP1-1 transgenic lines were significantly more resistant to X. campestris pv. vesicatoria than WT tomato fruits. In transgenic lines, bacterial infection was reduced up to 65% in comparison to the infection of WT plants. Our study demonstrates that the combination of the 4XW2/4XS cis-element from parsley with the synthetic antimicrobial peptide SP1-1 is a good alternative to protect tomato fruits against infections with X. campestris pv. vesicatoria.

  1. Monoclonal antibodies against a synthetic peptide from human immunodeficiency virus type 1 Nef protein

    DEFF Research Database (Denmark)

    Steinaa, L; Wulff, A M; Saermark, T

    1994-01-01

    Monoclonal antibodies against a synthetic peptide (aa 138-152) from HIV-1 Nef protein were produced and characterized. Three hybridoma lines producing monoclonal antibodies (MAbs) against the synthetic peptide were generated by fusion between P3-X63 Ag8.653 myeloma cells and BALB/c splenocytes from...... mice immunized with the synthetic peptide coupled to keyhole limpet hemocyanin (KLH). The hybridomas were screened and selected by ELISA with the peptide coupled to bovine serum albumin (BSA) immobilized to the polystyrene surface and specificity for the peptide was confirmed by competitive ELISA...... with the peptide free in solution. The reactions of the MAbs with a 5-aa motif (WCYKL) included in the sequence were examined with synthetic peptides and two of the MAbs reacted with the motif. The recognitions of recombinant full-length Nef protein were also tested. One MAb reacted with the protein in both ELISA...

  2. Induction of human immunodeficiency virus (HIV-1 envelope specific cell-mediated immunity by a non-homologous synthetic peptide.

    Directory of Open Access Journals (Sweden)

    Ammar Achour

    2007-11-01

    Full Text Available Cell mediated immunity, including efficient CTL response, is required to prevent HIV-1 from cell-to-cell transmission. In previous investigations, we have shown that B1 peptide derived by Fourier transformation of HIV-1 primary structures and sharing no sequence homology with the parent proteins was able to generate antiserum which recognizes envelope and Tat proteins. Here we have investigated cellular immune response towards a novel non-homologous peptide, referred to as cA1 peptide.The 20 amino acid sequence of cA1 peptide was predicted using the notion of peptide hydropathic properties; the peptide is encoded by the complementary anti-sense DNA strand to the sense strand of previously described non-homologous A1 peptide. In this report we demonstrate that the cA1 peptide can be a target for major histocompatibility complex (MHC class I-restricted cytotoxic T lymphocytes in HIV-1-infected or envelope-immunized individuals. The cA1 peptide is recognized in association with different MHC class I allotypes and could prime in vitro CTLs, derived from gp160-immunized individuals capable to recognize virus variants.For the first time a theoretically designed immunogen involved in broad-based cell-immune memory activation is described. Our findings may thus contribute to the advance in vaccine research by describing a novel strategy to develop a synthetic AIDS vaccine.

  3. AP-1/KIF13A Blocking Peptides Impair Melanosome Maturation and Melanin Synthesis

    Directory of Open Access Journals (Sweden)

    Cécile Campagne

    2018-02-01

    Full Text Available Melanocytes are specialized cells that generate unique organelles called melanosomes in which melanin is synthesized and stored. Melanosome biogenesis and melanocyte pigmentation require the transport and delivery of melanin synthesizing enzymes, such as tyrosinase and related proteins (e.g., TYRP1, from endosomes to maturing melanosomes. Among the proteins controlling endosome-melanosome transport, AP-1 together with KIF13A coordinates the endosomal sorting and trafficking of TYRP1 to melanosomes. We identify here β1-adaptin AP-1 subunit-derived peptides of 5 amino acids that block the interaction of KIF13A with AP-1 in cells. Incubating these peptides with human MNT-1 cells or 3D-reconstructed pigmented epidermis decreases pigmentation by impacting the maturation of melanosomes in fully pigmented organelles. This study highlights that peptides targeting the intracellular trafficking of melanocytes are candidate molecules to tune pigmentation in health and disease.

  4. Biological effects and metabolic rates of glucagonlike peptide-1 7-36 amide and glucagonlike peptide-1 7-37 in healthy subjects are indistinguishable

    DEFF Research Database (Denmark)

    Orskov, C; Wettergren, A; Holst, J J

    1993-01-01

    .0 +/- 34.6 pmol/h x L-1). Both GLP-1 7-36 amide and GLP-1 7-37 lowered the plasma concentration of free fatty acids significantly. The plasma half-lives of GLP-1 7-36 amide and GLP-1 7-37 were 5.3 +/- 0.4 vs. 6.1 +/- 0.8 min, and the metabolic clearance rates of the two peptides also were similar (14...

  5. Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism

    DEFF Research Database (Denmark)

    Hansen, Morten S S; Tencerova, Michaela; Frølich, Jacob

    2018-01-01

    The relationship between gut and skeleton is increasingly recognised as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibi......-clinical investigations, clinical trials are needed to clarify if similar effects are present and clinically relevant in humans. This article is protected by copyright. All rights reserved....

  6. 16 CFR 1.23 - Quantity limit rules.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Quantity limit rules. 1.23 Section 1.23 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL... Robinson-Patman Act. These rules have the force and effect of law. [32 FR 8444, June 13, 1967. Redesignated...

  7. Polymorphism of glucagon-like peptide-1 receptor gene (rs1042044 ...

    African Journals Online (AJOL)

    Previous investigations indicated that glucagon-like peptide-1 (GLP-1) played important roles in bone turnover via GLP-1 receptors (GLP1Rs) in postmenopausal state. Furthermore, polymorphisms in GLP1R gene were suggested to affect the function of GLP1Rs and be associated with many diseases. However, the ...

  8. Chimeric peptide-mediated siRNA transduction to inhibit HIV-1 infection.

    Science.gov (United States)

    Bivalkar-Mehla, Shalmali; Mehla, Rajeev; Chauhan, Ashok

    2017-04-01

    Persistent human immunodeficiency virus 1 (HIV-1) infection provokes immune activation and depletes CD4 +  lymphocytes, leading to acquired immunodeficiency syndrome. Uninterrupted administration of combination antiretroviral therapy (cART) in HIV-infected patients suppresses viral replication to below the detectable level and partially restores the immune system. However, cART-unresponsive residual HIV-1 infection and elusive transcriptionally silent but reactivatable viral reservoirs maintain a permanent viral DNA blue print. The virus rebounds within a few weeks after interruption of suppressive therapy. Adjunct gene therapy to control viral replication by ribonucleic acid interference (RNAi) is a post-transcriptional gene silencing strategy that could suppress residual HIV-1 burden and overcome viral resistance. Small interfering ribonucleic acids (siRNAs) are efficient transcriptional inhibitors, but need delivery systems to reach inside target cells. We investigated the potential of chimeric peptide (FP-PTD) to deliver specific siRNAs to HIV-1-susceptible and permissive cells. Chimeric FP-PTD peptide was designed with an RNA binding domain (PTD) to bind siRNA and a cell fusion peptide domain (FP) to enter cells. FP-PTD-siRNA complex entered and inhibited HIV-1 replication in susceptible cells, and could be a candidate for in vivo testing.

  9. Temperature-dependent loop formation kinetics in flexible peptides studied by time-resolved fluorescence spectroscopy

    Directory of Open Access Journals (Sweden)

    Harekrushna Sahoo

    2006-01-01

    Full Text Available Looping rates in short polypeptides can be determined by intramolecular fluorescence quenching of a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo by tryptophan. By this methodology, the looping rates in glycine-serine peptides with the structure Trp-(Gly-Sern-Dbo-NH2 of different lengths (n = 0–10 were determined in dependence on temperature in D2O and the activation parameters were derived. In general, the looping rate increases with decreasing peptide length, but the shortest peptide (n=0 shows exceptional behavior because its looping rate is slower than that for the next longer ones (n=1,2. The activation energies increase from 17.5 kJ mol−1 for the longest peptide (n=10 to 20.5 kJ mol−1 for the shortest one (n=0, while the pre-exponential factors (log⁡(A/s−1 range from 10.20 to 11.38. The data are interpreted in terms of an interplay between internal friction (stiffness of the biopolymer backbone and steric hindrance effects and solvent friction (viscosity-limited diffusion. For the longest peptides, the activation energies resemble more and more the value expected for solvent viscous flow. Internal friction is most important for the shortest peptides, causing a negative curvature and a smaller than ideal slope (ca. –1.1 of the double-logarithmic plots of the looping rates versus the number of peptide chain segments (N. Interestingly, the corresponding plot for the pre-exponential factors (logA versus logN shows the ideal slope (–1.5. While the looping rates can be used to assess the flexibility of peptides in a global way, it is suggested that the activation energies provide a measure of the “thermodynamic” flexibility of a peptide, while the pre-exponential factors reflect the “dynamic” flexibility.

  10. Recognition and Binding of a Helix-Loop-Helix Peptide to Carbonic Anhydrase Occurs via Partly Folded Intermediate Structures

    Science.gov (United States)

    Lignell, Martin; Becker, Hans-Christian

    2010-01-01

    Abstract We have studied the association of a helix-loop-helix peptide scaffold carrying a benzenesulfonamide ligand to carbonic anhydrase using steady-state and time-resolved fluorescence spectroscopy. The helix-loop-helix peptide, developed for biosensing applications, is labeled with the fluorescent probe dansyl, which serves as a polarity-sensitive reporter of the binding event. Using maximum entropy analysis of the fluorescence lifetime of dansyl at 1:1 stoichiometry reveals three characteristic fluorescence lifetime groups, interpreted as differently interacting peptide/protein structures. We characterize these peptide/protein complexes as mostly bound but unfolded, bound and partly folded, and strongly bound and folded. Furthermore, analysis of the fluorescence anisotropy decay resulted in three different dansyl rotational correlation times, namely 0.18, 1.2, and 23 ns. Using the amplitudes of these times, we can correlate the lifetime groups with the corresponding fluorescence anisotropy component. The 23-ns rotational correlation time, which appears with the same amplitude as a 17-ns fluorescence lifetime, shows that the dansyl fluorophore follows the rotational diffusion of carbonic anhydrase when it is a part of the folded peptide/protein complex. A partly folded and partly hydrated interfacial structure is manifested in an 8-ns dansyl fluorescence lifetime and a 1.2-ns rotational correlation time. This structure, we believe, is similar to a molten-globule-like interfacial structure, which allows segmental movement and has a higher degree of solvent exposure of dansyl. Indirect excitation of dansyl on the helix-loop-helix peptide through Förster energy transfer from one or several tryptophans in the carbonic anhydrase shows that the helix-loop-helix scaffold binds to a tryptophan-rich domain of the carbonic anhydrase. We conclude that binding of the peptide to carbonic anhydrase involves a transition from a disordered to an ordered structure of the

  11. Hb taradale [beta82(EF6)Lys-->Arg]: a novel mutation at a 2,3-diphosphoglycerate binding site.

    Science.gov (United States)

    Brennan, Stephen O; Sheen, Campbell; Chan, Tim; George, Peter M

    2005-01-01

    Hb Taradale [beta82(EF6)Lys-->Arg] was initially detected as a split Hb A0 peak on Hb A1c, monitoring. Red cell parameters, hemoglobin (Hb) electrophoresis and stability tests were normal. Mass spectrometry (ms) clearly identified a variant beta chain with a mass increase of 28 Da and peptide mapping located the mutation site to peptide betaT-9. DNA sequencing confirmed the presence of a novel beta82(EF6)Lys-->Arg mutation. This conservative substitution at a 2,3-diphosphoglycerate (2,3-DPG) binding site did not, however, appear to affect the P50 for oxygen binding.

  12. Exaggerated glucagon-like peptide-1 and blunted glucose-dependent insulinotropic peptide secretion are associated with Roux-en-Y gastric bypass but not adjustable gastric banding

    DEFF Research Database (Denmark)

    Korner, Judith; Bessler, Marc; Inabnet, William

    2007-01-01

    BACKGROUND: The aim of this study was to measure the circulating levels of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon in patients who had undergone adjustable gastric banding (BND) or Roux-en-Y gastric bypass (RYGB) to understand the differences...

  13. Blocking peptides against HBV: PreS1 protein selected from a phage display library

    International Nuclear Information System (INIS)

    Wang, Wei; Liu, Yang; Zu, Xiangyang; Jin, Rui; Xiao, Gengfu

    2011-01-01

    Highlights: → Successfully selected specific PreS1-interacting peptides by using phage displayed library. → Alignment of the positive phage clones revealed a consensus PreS1 binding motif. → A highly enriched peptide named P7 had a strong binding ability for PreS1. → P7 could block PreS1 attachment. -- Abstract: The PreS1 protein is present on the outermost part of the hepatitis B virus (HBV) surface and has been shown to have a pivotal function in viral infectivity and assembly. The development of reagents with high affinity and specificity for PreS1 is of great significance for early diagnosis and treatment of HBV infection. A phage display library of dodecapeptide was screened for interactions with purified PreS1 protein. Alignment of the positive phage clones revealed a putative consensus PreS1 binding motif of HX n HX m HP/R. Moreover, a peptide named P7 (KHMHWHPPALNT) was highly enriched and occurred with a surprisingly high frequency of 72%. A thermodynamic study revealed that P7 has a higher binding affinity to PreS1 than the other peptides. Furthermore, P7 was able to abrogate the binding of HBV virions to the PreS1 antibody, suggesting that P7 covers key functional sites on the native PreS1 protein. This newly isolated peptide may, therefore, be a new therapeutic candidate for the treatment of HBV. The consensus motif could be modified to deliver imaging, diagnostic, and therapeutic agents to tissues affected by HBV.

  14. Blocking peptides against HBV: PreS1 protein selected from a phage display library

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Liu, Yang; Zu, Xiangyang; Jin, Rui [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China)

    2011-09-09

    Highlights: {yields} Successfully selected specific PreS1-interacting peptides by using phage displayed library. {yields} Alignment of the positive phage clones revealed a consensus PreS1 binding motif. {yields} A highly enriched peptide named P7 had a strong binding ability for PreS1. {yields} P7 could block PreS1 attachment. -- Abstract: The PreS1 protein is present on the outermost part of the hepatitis B virus (HBV) surface and has been shown to have a pivotal function in viral infectivity and assembly. The development of reagents with high affinity and specificity for PreS1 is of great significance for early diagnosis and treatment of HBV infection. A phage display library of dodecapeptide was screened for interactions with purified PreS1 protein. Alignment of the positive phage clones revealed a putative consensus PreS1 binding motif of HX{sub n}HX{sub m}HP/R. Moreover, a peptide named P7 (KHMHWHPPALNT) was highly enriched and occurred with a surprisingly high frequency of 72%. A thermodynamic study revealed that P7 has a higher binding affinity to PreS1 than the other peptides. Furthermore, P7 was able to abrogate the binding of HBV virions to the PreS1 antibody, suggesting that P7 covers key functional sites on the native PreS1 protein. This newly isolated peptide may, therefore, be a new therapeutic candidate for the treatment of HBV. The consensus motif could be modified to deliver imaging, diagnostic, and therapeutic agents to tissues affected by HBV.

  15. Annexin 1 and Melanocortin Peptide Therapy for Protection Against Ischaemic-Reperfusion Damage in the Heart

    Directory of Open Access Journals (Sweden)

    F.N.E. Gavins

    2006-01-01

    Full Text Available Cardiovascular disease is a major cause of mortality within the western world affecting 2.7 million British people. This review highlights the beneficial effects of naturally occurring hormones and their peptides, in myocardial ischaemic-injury (MI models, a disease pathology in which cytokines and neutrophils play a causal role. Here we discuss two distinct classes of endogenous peptides: the steroid inducible annexin 1 and the melanocortin peptides. Annexin 1 and the melanocortins counteract the most important part of the host inflammatory response, namely, the process of leukocyte extravasation, as well as release of proinflammatory mediators. Their biological effects are mediated via the seven transmembrane G-protein-coupled receptors, the fMLP receptor family (or FPR, and the melanocortin receptors, respectively. Pharmacological analysis has demonstrated that the first 24 amino acids of the N-terminus (termed Ac2-26 are the most active region. Both exogenous annexin 1 and its peptides demonstrate cardioprotectiveness and continuing work is required to understand this annexin 1/FPR relationship fully. The melanocortin peptides are derived from a precursor molecule called the POMC protein. These peptides display potent anti-inflammatory effects in human and animal models of disease. In MI, the MC3R has been demonstrated to play an important role in mediating the protective effects of these peptides. The potential anti-inflammatory role for endogenous peptides in cardiac disease is in its infancy. The inhibition of cell migration and release of cytokines and other soluble mediators appears to play an important role in affording protection in ischaemic injury and thus may lead to potential therapeutic targets.

  16. Dendropsophin 1, a novel antimicrobial peptide from the skin secretion of the endemic Colombian frog Dendropsophus columbianus.

    Science.gov (United States)

    Triana-Vidal, Luz Elena; Castro, Mariana Souza; Pires Júnior, Osmindo Rodrigues; Álvares, Alice Cunha Morales; de Freitas, Sonia Maria; Fontes, Wagner; Vargas, Jimmy Alexander Guerrero; Zúñiga-Baos, Jorge Alberto; Correia Batista, Isabel de Fátima; Grellier, Philippe; Charneau, Sébastien

    2018-06-01

    In efforts to find new antimicrobial peptides (AMPs), we studied the skin secretion of the endemic Colombian frog Dendropsophus columbianus belonging to a genus that has not been investigated previously. From HPLC-fractionated secretion, we identified one peptide with slightly antibacterial activity. Its peptide sequence showed no sequence similarity to current annotated peptides. We named this novel peptide dendropsophin 1 (Dc1). Afterward, two analogues were designed (Dc1.1 and Dc1.2) to improve the cationic and amphipathic features. Then, their antiproliferative and cytotoxic properties were evaluated against several pathogens including bacteria, fungi, protozoa and also mammalian cells. Dc1 and its two analogues exhibited moderate antibacterial activities and no hemolytic and cytotoxic effects on mammalian cells. Analogue Dc1.2 showed slightly improved antibacterial properties. Their secondary structures were characterised using CD spectroscopy and Dc1.2 displayed a higher α-helix content and thermal stability compared to Dc1 and Dc1.1 in hydrophobic experimental conditions.

  17. Peptide chemistry toolbox - Transforming natural peptides into peptide therapeutics.

    Science.gov (United States)

    Erak, Miloš; Bellmann-Sickert, Kathrin; Els-Heindl, Sylvia; Beck-Sickinger, Annette G

    2018-06-01

    The development of solid phase peptide synthesis has released tremendous opportunities for using synthetic peptides in medicinal applications. In the last decades, peptide therapeutics became an emerging market in pharmaceutical industry. The need for synthetic strategies in order to improve peptidic properties, such as longer half-life, higher bioavailability, increased potency and efficiency is accordingly rising. In this mini-review, we present a toolbox of modifications in peptide chemistry for overcoming the main drawbacks during the transition from natural peptides to peptide therapeutics. Modifications at the level of the peptide backbone, amino acid side chains and higher orders of structures are described. Furthermore, we are discussing the future of peptide therapeutics development and their impact on the pharmaceutical market. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Glucagon-like peptide-1 (GLP-1) receptor agonism or DPP-4 inhibition does not accelerate neoplasia in carcinogen treated mice

    DEFF Research Database (Denmark)

    Kissow, Hannelouise; Hartmann, Bolette; Holst, Jens Juul

    2012-01-01

    Glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) are secreted in parallel from the intestinal endocrine cells after nutrient intake. GLP-1 is an incretin hormone and analogues are available for the treatment of type 2 diabetes mellitus (T2DM). GLP-2 is an intestinal growth horm...

  19. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans

    1990-01-01

    for antibody binding to the immunizing antigen. Antisera to C-peptide 2, stained islet beta-cells on mouse and rat, but not monkey pancreas sections in immunocytochemical analysis. Preabsorption to the synthetic C-peptide 2, but not the synthetic mouse and rat C-peptide 1 abolished staining. In conclusion we......Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did...... not seem to increase the end point titre as tested in direct ELISA. The specificity of the antiserum was determined by competitive ELISA and histochemistry on pancreas sections. Only the synthetic C-peptide 2, but not the homologous synthetic C-peptide 1 from mouse and rat competed efficiently in ELISA...

  20. Neural regulation of glucagon-like peptide-1 secretion in pigs

    DEFF Research Database (Denmark)

    Hansen, Lene; Lampert, Sarah; Mineo, Hitoshi

    2004-01-01

    Glucagon-like peptide (GLP)-1 is secreted rapidly from the intestine postprandially. We therefore investigated its possible neural regulation. With the use of isolated perfused porcine ileum, GLP-1 secretion was measured in response to electrical stimulation of the mixed, perivascular nerve supply...

  1. Unusual structural transition of antimicrobial VP1 peptide.

    Science.gov (United States)

    Shanmugam, Ganesh; Phambu, Nsoki; Polavarapu, Prasad L

    2011-05-01

    VP1 peptide, an active domain of m-calpain enzyme with antimicrobial activity is found to undergo an unusual conformational transition in trifluoroethanol (TFE) solvent. The nature of, and time dependent variations in, circular dichroism associated with the amide I vibrations, suggest that VP1 undergoes self-aggregation forming anti-parallel β-sheet structure in TFE. Transmission electron micrograph (TEM) images revealed that β-sheet aggregates formed by VP1 possess fibril-like assemblies. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Effect of N-Terminal Acylation on the Activity of Myostatin Inhibitory Peptides.

    Science.gov (United States)

    Takayama, Kentaro; Nakamura, Akari; Rentier, Cédric; Mino, Yusaku; Asari, Tomo; Saga, Yusuke; Taguchi, Akihiro; Yakushiji, Fumika; Hayashi, Yoshio

    2016-04-19

    Inhibition of myostatin, which negatively regulates skeletal muscle growth, is a promising strategy for the treatment of muscle atrophic disorders, such as muscular dystrophy, cachexia and sarcopenia. Recently, we identified peptide A (H-WRQNTRYSRIEAIKIQILSKLRL-NH2 ), the 23-amino-acid minimum myostatin inhibitory peptide derived from mouse myostatin prodomain, and highlighted the importance of its N-terminal tryptophan residue for the effective inhibition. In this study, we synthesized a series of acylated peptide derivatives focused on the tryptophan residue to develop potent myostatin inhibitors. As a result of the investigation, a more potent derivative of peptide A was successfully identified in which the N-terminal tryptophan residue is replaced with a 2-naphthyloxyacetyl moiety to give an inhibitory peptide three times (1.19±0.11 μm) more potent than parent peptide A (3.53±0.25 μm). This peptide could prove useful as a new starting point for the development of improved inhibitory peptides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Monomeric Aβ(1-40) and Aβ(1-42) Peptides in Solution Adopt Very Similar Ramachandran Map Distributions That Closely Resemble Random Coil.

    Science.gov (United States)

    Roche, Julien; Shen, Yang; Lee, Jung Ho; Ying, Jinfa; Bax, Ad

    2016-02-09

    The pathogenesis of Alzheimer's disease is characterized by the aggregation and fibrillation of amyloid peptides Aβ(1-40) and Aβ(1-42) into amyloid plaques. Despite strong potential therapeutic interest, the structural pathways associated with the conversion of monomeric Aβ peptides into oligomeric species remain largely unknown. In particular, the higher aggregation propensity and associated toxicity of Aβ(1-42) compared to that of Aβ(1-40) are poorly understood. To explore in detail the structural propensity of the monomeric Aβ(1-40) and Aβ(1-42) peptides in solution, we recorded a large set of nuclear magnetic resonance (NMR) parameters, including chemical shifts, nuclear Overhauser effects (NOEs), and J couplings. Systematic comparisons show that at neutral pH the Aβ(1-40) and Aβ(1-42) peptides populate almost indistinguishable coil-like conformations. Nuclear Overhauser effect spectra collected at very high resolution remove assignment ambiguities and show no long-range NOE contacts. Six sets of backbone J couplings ((3)JHNHα, (3)JC'C', (3)JC'Hα, (1)JHαCα, (2)JNCα, and (1)JNCα) recorded for Aβ(1-40) were used as input for the recently developed MERA Ramachandran map analysis, yielding residue-specific backbone ϕ/ψ torsion angle distributions that closely resemble random coil distributions, the absence of a significantly elevated propensity for β-conformations in the C-terminal region of the peptide, and a small but distinct propensity for αL at K28. Our results suggest that the self-association of Aβ peptides into toxic oligomers is not driven by elevated propensities of the monomeric species to adopt β-strand-like conformations. Instead, the accelerated disappearance of Aβ NMR signals in D2O over H2O, particularly pronounced for Aβ(1-42), suggests that intermolecular interactions between the hydrophobic regions of the peptide dominate the aggregation process.

  4. Application of synthetic peptides for detection of anti-citrullinated peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Holm, Bettina Eide; Slot, Ole

    2016-01-01

    Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and represent an important tool for the serological diagnosis of RA. In this study, we describe ACPA reactivity to overlapping citrullinated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-derived peptides...... (n=40), systemic lupus erythematosus (n=20), Sjögren's syndrome (n=40)) were screened for antibody reactivity. Antibodies to a panel of five citrullinated EBNA-1 peptides were found in 67% of RA sera, exclusively of the IgG isotype, while 53% of the patient sera reacted with a single peptide......, ARGGSRERARGRGRG-Cit-GEKR, accounting for more than half of the ACPA reactivity alone. Moreover, these antibodies were detected in 10% of CCP2-negative RA sera. In addition, 47% of the RA sera reacted with two or three citrullinated EBNA-1 peptides from the selected peptide panel. Furthermore, a negative...

  5. Pro-opiomelanocortin-derived peptides in the pig pituitary: alpha- and gamma 1-melanocyte-stimulating hormones and their glycine-extended forms

    DEFF Research Database (Denmark)

    Fenger, M

    1988-01-01

    Pro-opiomelanocortin (POMC)-related peptides in extracts of anterior and neurointermediate pituitary lobes from pigs were characterized by gel chromatography, reversed-phase chromatography and radioimmunoassays. The peptide content was ca. 3-fold greater in the anterior lobe compared...... to the neurointermediate lobe (19.8 nmol POMC/anterior lobe vs 7.0 nmol/neurointermediate lobe). In the neurointermediate lobe 93% of POMC was processed to alpha-melanocyte-stimulating hormone (alpha-MSH) and analogs exclusively of low molecular weight. Most of the remaining adrenocorticotropic hormone (ACTH...... as alpha-MSH and analogs (94%). However, more than 95% of these peptides were of high molecular weight. In the anterior lobe 2.3% of N-POMC was processed and 94% was amidated gamma-MSH of only high molecular weight. These results show that gamma-MSH and alpha-MSH are amidated to the same extent...

  6. A nonribosomal peptide synthetase (Pes1) confers protection against oxidative stress in Aspergillus fumigatus.

    Science.gov (United States)

    Reeves, Emer P; Reiber, Kathrin; Neville, Claire; Scheibner, Olaf; Kavanagh, Kevin; Doyle, Sean

    2006-07-01

    Aspergillus fumigatus is an important human fungal pathogen. The Aspergillus fumigatus genome contains 14 nonribosomal peptide synthetase genes, potentially responsible for generating metabolites that contribute to organismal virulence. Differential expression of the nonribosomal peptide synthetase gene, pes1, in four strains of Aspergillus fumigatus was observed. The pattern of pes1 expression differed from that of a putative siderophore synthetase gene, sidD, and so is unlikely to be involved in iron acquisition. The Pes1 protein (expected molecular mass 698 kDa) was partially purified and identified by immunoreactivity, peptide mass fingerprinting (36% sequence coverage) and MALDI LIFT-TOF/TOF MS (four internal peptides sequenced). A pes1 disruption mutant (delta pes1) of Aspergillus fumigatus strain 293.1 was generated and confirmed by Southern and western analysis, in addition to RT-PCR. The delta pes1 mutant also showed significantly reduced virulence in the Galleria mellonella model system (P < 0.001) and increased sensitivity to oxidative stress (P = 0.002) in culture and during neutrophil-mediated phagocytosis. In addition, the mutant exhibited altered conidial surface morphology and hydrophilicity, compared to Aspergillus fumigatus 293.1. It is concluded that pes1 contributes to improved fungal tolerance against oxidative stress, mediated by the conidial phenotype, during the infection process.

  7. Human DMBT1-Derived Cell-Penetrating Peptides for Intracellular siRNA Delivery

    DEFF Research Database (Denmark)

    Tuttolomondo, Martina; Casella, Cinzia; Hansen, Pernille Lund

    2017-01-01

    tumor 1) is a pattern recognition molecule that interacts with polyanions and recognizes and aggregates bacteria. Taking advantage of these properties, we investigated whether specific synthetic DMBT1-derived peptides could be used to formulate nanoparticles for siRNA administration. Using......-potential, circular dichroism, dynamic light scattering, and transmission electron microscopy revealed negatively charged nanoparticles with an average diameter of 10-800 nm, depending on the reaction conditions, and a spherical or rice-shaped morphology, depending on the peptide and β-helix conformation. We...

  8. Exacerbation of collagen induced arthritis by Fcγ receptor targeted collagen peptide due to enhanced inflammatory chemokine and cytokine production

    Directory of Open Access Journals (Sweden)

    Szarka E

    2012-04-01

    Full Text Available Eszter Szarka1*, Zsuzsa Neer1*, Péter Balogh2, Monika Ádori1, Adrienn Angyal1, József Prechl3, Endre Kiss1,3, Dorottya Kövesdi1, Gabriella Sármay11Department of Immunology, Eötvös Loránd University, 1117 Budapest, 2Department of Immunology and Biotechnology, University of Pécs, Pécs, 3Immunology Research Group of the Hungarian Academy of Science at Eötvös Loránd University, 1117 Budapest, Hungary*These authors contributed equally to this workAbstract: Antibodies specific for bovine type II collagen (CII and Fcγ receptors play a major role in collagen-induced arthritis (CIA, a mouse model of rheumatoid arthritis (RA. Our aim was to clarify the mechanism of immune complex-mediated inflammation and modulation of the disease. CII pre-immunized DBA/1 mice were intravenously boosted with extravidin coupled biotinylated monomeric CII-peptide epitope (ARGLTGRPGDA and its complexes with biotinylated FcγRII/III specific single chain Fv (scFv fragment. Disease scores were monitored, antibody titers and cytokines were determined by ELISA, and binding of complexes was detected by flow cytometry and immune histochemistry. Cytokine and chemokine secretion was monitored by protein profiler microarray. When intravenously administered into collagen-primed DBA/1 mice, both CII-peptide and its complex with 2.4G2 scFv significantly accelerated CIA and increased the severity of the disease, whereas the monomeric peptide and monomeric 2.4G2 scFv had no effect. FcγRII/III targeted CII-peptide complexes bound to marginal zone macrophages and dendritic cells, and significantly elevated the synthesis of peptide-specific IgG2a. Furthermore, CII-peptide containing complexes augmented the in vivo secretion of cytokines, including IL-10, IL-12, IL-17, IL-23, and chemokines (CXCL13, MIP-1, MIP-2. These data indicate that complexes formed by the CII-peptide epitope aggravate CIA by inducing the secretion of chemokines and the IL-12/23 family of pro

  9. Neuronal Calcium Sensor-1 Binds the D2 Dopamine Receptor and G-protein-coupled Receptor Kinase 1 (GRK1) Peptides Using Different Modes of Interactions.

    Science.gov (United States)

    Pandalaneni, Sravan; Karuppiah, Vijaykumar; Saleem, Muhammad; Haynes, Lee P; Burgoyne, Robert D; Mayans, Olga; Derrick, Jeremy P; Lian, Lu-Yun

    2015-07-24

    Neuronal calcium sensor-1 (NCS-1) is the primordial member of the neuronal calcium sensor family of EF-hand Ca(2+)-binding proteins. It interacts with both the G-protein-coupled receptor (GPCR) dopamine D2 receptor (D2R), regulating its internalization and surface expression, and the cognate kinases GRK1 and GRK2. Determination of the crystal structures of Ca(2+)/NCS-1 alone and in complex with peptides derived from D2R and GRK1 reveals that the differential recognition is facilitated by the conformational flexibility of the C-lobe-binding site. We find that two copies of the D2R peptide bind within the hydrophobic crevice on Ca(2+)/NCS-1, but only one copy of the GRK1 peptide binds. The different binding modes are made possible by the C-lobe-binding site of NCS-1, which adopts alternative conformations in each complex. C-terminal residues Ser-178-Val-190 act in concert with the flexible EF3/EF4 loop region to effectively form different peptide-binding sites. In the Ca(2+)/NCS-1·D2R peptide complex, the C-terminal region adopts a 310 helix-turn-310 helix, whereas in the GRK1 peptide complex it forms an α-helix. Removal of Ser-178-Val-190 generated a C-terminal truncation mutant that formed a dimer, indicating that the NCS-1 C-terminal region prevents NCS-1 oligomerization. We propose that the flexible nature of the C-terminal region is essential to allow it to modulate its protein-binding sites and adapt its conformation to accommodate both ligands. This appears to be driven by the variability of the conformation of the C-lobe-binding site, which has ramifications for the target specificity and diversity of NCS-1. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Different domains of the glucagon and glucagon-like peptide-1 receptors provide the critical determinants of ligand selectivity

    DEFF Research Database (Denmark)

    Runge, S; Wulff, B S; Madsen, K

    2003-01-01

    analysed chimeric glucagon/GLP-1 peptides for their ability to bind and activate the glucagon receptor, the GLP-1 receptor and chimeric glucagon/GLP-1 receptors. The chimeric peptide GLP-1(7-20)/glucagon(15-29) was unable to bind and activate the glucagon receptor. Substituting the glucagon receptor core......-terminus of chimera A with the corresponding glucagon receptor segments re-established the ability to distinguish GLP-1(7-20)/glucagon(15-29) from glucagon. Corroborant results were obtained with the opposite chimeric peptide glucagon(1-14)/GLP-1(21-37). (3) The results suggest that the glucagon and GLP-1 receptor......(1) Glucagon and glucagon-like peptide-1 (GLP-1) are homologous peptide hormones with important functions in glucose metabolism. The receptors for glucagon and GLP-1 are homologous family B G-protein coupled receptors. The GLP-1 receptor amino-terminal extracellular domain is a major determinant...

  11. Truncated Glucagon-like Peptide-1 and Exendin-4 α-Conotoxin pl14a Peptide Chimeras Maintain Potency and α-Helicity and Reveal Interactions Vital for cAMP Signaling in Vitro*

    Science.gov (United States)

    Swedberg, Joakim E.; Schroeder, Christina I.; Mitchell, Justin M.; Fairlie, David P.; Edmonds, David J.; Griffith, David A.; Ruggeri, Roger B.; Derksen, David R.; Loria, Paula M.; Price, David A.; Liras, Spiros; Craik, David J.

    2016-01-01

    Glucagon-like peptide-1 (GLP-1) signaling through the glucagon-like peptide 1 receptor (GLP-1R) is a key regulator of normal glucose metabolism, and exogenous GLP-1R agonist therapy is a promising avenue for the treatment of type 2 diabetes mellitus. To date, the development of therapeutic GLP-1R agonists has focused on producing drugs with an extended serum half-life. This has been achieved by engineering synthetic analogs of GLP-1 or the more stable exogenous GLP-1R agonist exendin-4 (Ex-4). These synthetic peptide hormones share the overall structure of GLP-1 and Ex-4, with a C-terminal helical segment and a flexible N-terminal tail. Although numerous studies have investigated the molecular determinants underpinning GLP-1 and Ex-4 binding and signaling through the GLP-1R, these have primarily focused on the length and composition of the N-terminal tail or on how to modulate the helicity of the full-length peptides. Here, we investigate the effect of C-terminal truncation in GLP-1 and Ex-4 on the cAMP pathway. To ensure helical C-terminal regions in the truncated peptides, we produced a series of chimeric peptides combining the N-terminal portion of GLP-1 or Ex-4 and the C-terminal segment of the helix-promoting peptide α-conotoxin pl14a. The helicity and structures of the chimeric peptides were confirmed using circular dichroism and NMR, respectively. We found no direct correlation between the fractional helicity and potency in signaling via the cAMP pathway. Rather, the most important feature for efficient receptor binding and signaling was the C-terminal helical segment (residues 22–27) directing the binding of Phe22 into a hydrophobic pocket on the GLP-1R. PMID:27226591

  12. Fall in C-Peptide During First 4 Years From Diagnosis of Type 1 Diabetes: Variable Relation to Age, HbA1c, and Insulin Dose.

    Science.gov (United States)

    Hao, Wei; Gitelman, Steven; DiMeglio, Linda A; Boulware, David; Greenbaum, Carla J

    2016-10-01

    We aimed to describe the natural history of residual insulin secretion in Type 1 Diabetes TrialNet participants over 4 years from diagnosis and relate this to previously reported alternative clinical measures reflecting β-cell secretory function. Data from 407 subjects from 5 TrialNet intervention studies were analyzed. All subjects had baseline stimulated C-peptide values of ≥0.2 nmol/L from mixed-meal tolerance tests (MMTTs). During semiannual visits, C-peptide values from MMTTs, HbA1c, and insulin doses were obtained. The percentage of individuals with stimulated C-peptide of ≥0.2 nmol/L or detectable C-peptide of ≥0.017 nmol/L continued to diminish over 4 years; this was markedly influenced by age. At 4 years, only 5% maintained their baseline C-peptide secretion. The expected inverse relationships between C-peptide and HbA1c or insulin doses varied over time and with age. Combined clinical variables, such as insulin-dose adjusted HbA1c (IDAA1C) and the relationship of IDAA1C to C-peptide, also were influenced by age and time from diagnosis. Models using these clinical measures did not fully predict C-peptide responses. IDAA1C ≤9 underestimated the number of individuals with stimulated C-peptide ≥0.2 nmol/L, especially in children. Current trials of disease-modifying therapy for type 1 diabetes should continue to use C-peptide as a primary end point of β-cell secretory function. Longer duration of follow-up is likely to provide stronger evidence of the effect of disease-modifying therapy on preservation of β-cell function. © 2016 by the American Diabetes Association.

  13. Small Molecule Drug Discovery at the Glucagon-Like Peptide-1 Receptor

    Directory of Open Access Journals (Sweden)

    Francis S. Willard

    2012-01-01

    Full Text Available The therapeutic success of peptide glucagon-like peptide-1 (GLP-1 receptor agonists for the treatment of type 2 diabetes mellitus has inspired discovery efforts aimed at developing orally available small molecule GLP-1 receptor agonists. Although the GLP-1 receptor is a member of the structurally complex class B1 family of GPCRs, in recent years, a diverse array of orthosteric and allosteric nonpeptide ligands has been reported. These compounds include antagonists, agonists, and positive allosteric modulators with intrinsic efficacy. In this paper, a comprehensive review of currently disclosed small molecule GLP-1 receptor ligands is presented. In addition, examples of “ligand bias” and “probe dependency” for the GLP-1 receptor are discussed; these emerging concepts may influence further optimization of known molecules or persuade designs of expanded screening strategies to identify novel chemical starting points for GLP-1 receptor drug discovery.

  14. Radio-immunoassays for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2)

    DEFF Research Database (Denmark)

    Orskov, C; Holst, J J

    1987-01-01

    in rabbits after carbodiimide conjugation of peptides to BSA. The selected antisera showed neither mutual cross-reactivity nor cross-reacted with any other peptide of the glucagon family. Trypsin digestion experiments showed that both antisera were directed against the C-terminus of the antigen peptides...

  15. A Photolabile Linker for the Solid-Phase Synthesis of Peptide Hydrazides and Heterocycles

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland

    2014-01-01

    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino adds, including those with side......-chain protected residues at the C-terminal of the resulting peptide hydrazide, and are useful for the synthesis of dihydropyrano[2,3-c]pyrazoles. The linker is compatible with most commonly used coupling reagents and protecting groups for solid-phase peptide synthesis....

  16. Structural analysis of a functional DIAP1 fragment bound to grim and hid peptides.

    Science.gov (United States)

    Wu, J W; Cocina, A E; Chai, J; Hay, B A; Shi, Y

    2001-07-01

    The inhibitor of apoptosis protein DIAP1 suppresses apoptosis in Drosophila, with the second BIR domain (BIR2) playing an important role. Three proteins, Hid, Grim, and Reaper, promote apoptosis, in part by binding to DIAP1 through their conserved N-terminal sequences. The crystal structures of DIAP1-BIR2 by itself and in complex with the N-terminal peptides from Hid and Grim reveal that these peptides bind a surface groove on DIAP1, with the first four amino acids mimicking the binding of the Smac tetrapeptide to XIAP. The next 3 residues also contribute to binding through hydrophobic interactions. Interestingly, peptide binding induces the formation of an additional alpha helix in DIAP1. Our study reveals the structural conservation and diversity necessary for the binding of IAPs by the Drosophila Hid/Grim/Reaper and the mammalian Smac proteins.

  17. Antimicrobial properties of two novel peptides derived from Theobroma cacao osmotin.

    Science.gov (United States)

    Falcao, Loeni L; Silva-Werneck, Joseilde O; Ramos, Alessandra de R; Martins, Natalia F; Bresso, Emmanuel; Rodrigues, Magali A; Bemquerer, Marcelo P; Marcellino, Lucilia H

    2016-05-01

    The osmotin proteins of several plants display antifungal activity, which can play an important role in plant defense against diseases. Thus, this protein can be useful as a source for biotechnological strategies aiming to combat fungal diseases. In this work, we analyzed the antifungal activity of a cacao osmotin-like protein (TcOsm1) and of two osmotin-derived synthetic peptides with antimicrobial features, differing by five amino acids residues at the N-terminus. Antimicrobial tests showed that TcOsm1 expressed in Escherichia coli inhibits the growth of Moniliophthora perniciosa mycelium and Pichia pastoris X-33 in vitro. The TcOsm1-derived peptides, named Osm-pepA (H-RRLDRGGVWNLNVNPGTTGARVWARTK-NH2), located at R23-K49, and Osm-pepB (H-GGVWNLNVNPGTTGARVWARTK-NH2), located at G28-K49, inhibited growth of yeasts (Saccharomyces cerevisiae S288C and Pichia pastoris X-33) and spore germination of the phytopathogenic fungi Fusarium f. sp. glycines and Colletotrichum gossypi. Osm-pepA was more efficient than Osm-pepB for S. cerevisiae (MIC=40μM and MIC=127μM, respectively), as well as for P. pastoris (MIC=20μM and MIC=127μM, respectively). Furthermore, the peptides presented a biphasic performance, promoting S. cerevisiae growth in doses around 5μM and inhibiting it at higher doses. The structural model for these peptides showed that the five amino acids residues, RRLDR at Osm-pepA N-terminus, significantly affect the tertiary structure, indicating that this structure is important for the peptide antimicrobial potency. This is the first report of development of antimicrobial peptides from T. cacao. Taken together, the results indicate that the cacao osmotin and its derived peptides, herein studied, are good candidates for developing biotechnological tools aiming to control phytopathogenic fungi. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Nutrient-induced glucagon like peptide-1 release is modulated by serotonin

    NARCIS (Netherlands)

    Ripken, D.; Wielen, N. van der; Wortelboer, H.M.; Meijerink, J.; Witkamp, R.F.; Hendriks, H.F.J.

    2016-01-01

    Glucagon like peptide-1 (GLP-1) and serotonin are both involved in food intake regulation. GLP-1 release is stimulated upon nutrient interaction with G-protein coupled receptors by enteroendocrine cells (EEC), whereas serotonin is released from enterochromaffin cells (ECC). The central hypothesis

  19. Purification and characterization of insulin and the C-peptide of proinsulin from Przewalski's horse, zebra, rhino, and tapir (Perissodactyla).

    Science.gov (United States)

    Henry, J S; Lance, V A; Conlon, J M

    1993-02-01

    Within the order Perissodactyla, the primary structure of insulin has been strongly conserved. Insulin from Przewalski's horse and the mountain zebra (suborder Hippomorpha) is the same as that from the domestic horse and differs from insulin from the white rhinoceros and mountain tapir (suborder Ceratomorpha) by a single substitution (Gly-->Ser) at position 9 in the A-chain. A second molecular form of Przewalski's horse insulin isolated in this study was shown to represent the gamma-ethyl ester of the Glu17 residue of the A-chain. This component was probably formed during the extraction of the pancreas with acidified ethanol. The amino acid sequence of the C-peptide of proinsulin has been less well conserved. Zebra C-peptide comprises 31 amino acid residues and differs from Przewalski's horse and domestic horse C-peptide by one substitution (Gln30-->Pro). Rhino C-peptide was isolated only in a truncated form corresponding to residues (1-23) of intact C-peptide. Its amino acid sequence contains three substitutions compared with the corresponding region of horse C-peptide. It is postulated that the substitution (Pro23-->Thr) renders rhino C-peptide more liable to proteolytic cleavage by a chymotrypsin-like enzyme than horse C-peptide. C-peptide could not be identified in the extract of tapir pancreas, suggesting that proteolytic degradation may have been more extensive than in the rhino. In contrast to the ox and pig (order Artiodactyla), there was no evidence for the expression of more than one proinsulin gene in the species of Perissodactyla examined.

  20. Ghrelin suppresses cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) in the intestine, and attenuates the anorectic effects of CCK, PYY and GLP-1 in goldfish (Carassius auratus).

    Science.gov (United States)

    Blanco, Ayelén Melisa; Bertucci, Juan Ignacio; Valenciano, Ana Isabel; Delgado, María Jesús; Unniappan, Suraj

    2017-07-01

    Ghrelin is an important gut-derived hormone with an appetite stimulatory role, while most of the intestinal hormones, including cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 (GLP-1), are appetite-inhibitors. Whether these important peptides with opposing roles on food intake interact to regulate energy balance in fish is currently unknown. The aim of this study was to characterize the putative crosstalk between ghrelin and CCK, PYY and GLP-1 in goldfish (Carassius auratus). We first determined the localization of CCK, PYY and GLP-1 in relation to ghrelin and its main receptor GHS-R1a (growth hormone secretagogue 1a) in the goldfish intestine by immunohistochemistry. Colocalization of ghrelin/GHS-R1a and CCK/PYY/GLP-1 was found primarily in the luminal border of the intestinal mucosa. In an intestinal explant culture, a significant decrease in prepro-cck, prepro-pyy and proglucagon transcript levels was observed after 60min of incubation with ghrelin, which was abolished by preincubation with the GHS-R1a ghrelin receptor antagonist [D-Lys3]-GHRP-6 (except for proglucagon). The protein expression of PYY and GLP-1 was also downregulated by ghrelin. Finally, intraperitoneal co-administration of CCK, PYY or GLP-1 with ghrelin results in no modification of food intake in goldfish. Overall, results of the present study show for the first time in fish that ghrelin exerts repressive effects on enteric anorexigens. It is likely that these interactions mediate the stimulatory effects of ghrelin on feeding and metabolism in fish. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Antiviral activity of α-helical stapled peptides designed from the HIV-1 capsid dimerization domain

    Directory of Open Access Journals (Sweden)

    Cowburn David

    2011-05-01

    Full Text Available Abstract Background The C-terminal domain (CTD of HIV-1 capsid (CA, like full-length CA, forms dimers in solution and CTD dimerization is a major driving force in Gag assembly and maturation. Mutations of the residues at the CTD dimer interface impair virus assembly and render the virus non-infectious. Therefore, the CTD represents a potential target for designing anti-HIV-1 drugs. Results Due to the pivotal role of the dimer interface, we reasoned that peptides from the α-helical region of the dimer interface might be effective as decoys to prevent CTD dimer formation. However, these small peptides do not have any structure in solution and they do not penetrate cells. Therefore, we used the hydrocarbon stapling technique to stabilize the α-helical structure and confirmed by confocal microscopy that this modification also made these peptides cell-penetrating. We also confirmed by using isothermal titration calorimetry (ITC, sedimentation equilibrium and NMR that these peptides indeed disrupt dimer formation. In in vitro assembly assays, the peptides inhibited mature-like virus particle formation and specifically inhibited HIV-1 production in cell-based assays. These peptides also showed potent antiviral activity against a large panel of laboratory-adapted and primary isolates, including viral strains resistant to inhibitors of reverse transcriptase and protease. Conclusions These preliminary data serve as the foundation for designing small, stable, α-helical peptides and small-molecule inhibitors targeted against the CTD dimer interface. The observation that relatively weak CA binders, such as NYAD-201 and NYAD-202, showed specificity and are able to disrupt the CTD dimer is encouraging for further exploration of a much broader class of antiviral compounds targeting CA. We cannot exclude the possibility that the CA-based peptides described here could elicit additional effects on virus replication not directly linked to their ability to bind

  2. Crystal structure of the ligand-bound glucagon-like peptide-1 receptor extracellular domain.

    Science.gov (United States)

    Runge, Steffen; Thøgersen, Henning; Madsen, Kjeld; Lau, Jesper; Rudolph, Rainer

    2008-04-25

    The glucagon-like peptide-1 receptor (GLP-1R) belongs to Family B1 of the seven-transmembrane G protein-coupled receptors, and its natural agonist ligand is the peptide hormone glucagon-like peptide-1 (GLP-1). GLP-1 is involved in glucose homeostasis, and activation of GLP-1R in the plasma membrane of pancreatic beta-cells potentiates glucose-dependent insulin secretion. The N-terminal extracellular domain (nGLP-1R) is an important ligand binding domain that binds GLP-1 and the homologous peptide Exendin-4 with differential affinity. Exendin-4 has a C-terminal extension of nine amino acid residues known as the "Trp cage", which is absent in GLP-1. The Trp cage was believed to interact with nGLP-1R and thereby explain the superior affinity of Exendin-4. However, the molecular details that govern ligand binding and specificity of nGLP-1R remain undefined. Here we report the crystal structure of human nGLP-1R in complex with the antagonist Exendin-4(9-39) solved by the multiwavelength anomalous dispersion method to 2.2A resolution. The structure reveals that Exendin-4(9-39) is an amphipathic alpha-helix forming both hydrophobic and hydrophilic interactions with nGLP-1R. The Trp cage of Exendin-4 is not involved in binding to nGLP-1R. The hydrophobic binding site of nGLP-1R is defined by discontinuous segments including primarily a well defined alpha-helix in the N terminus of nGLP-1R and a loop between two antiparallel beta-strands. The structure provides for the first time detailed molecular insight into ligand binding of the human GLP-1 receptor, an established target for treatment of type 2 diabetes.

  3. Nutrient-induced glucagon like peptide-1 release is modulated by serotonin

    NARCIS (Netherlands)

    Ripken, Dina; Wielen, van der Nikkie; Wortelboer, Heleen M.; Meijerink, Jocelijn; Witkamp, Renger F.; Hendriks, Henk F.J.

    2016-01-01

    Glucagon like peptide-1 (GLP-1) and serotonin are both involved in food intake regulation. GLP-1 release is stimulated upon nutrient interaction with G-protein coupled receptors by enteroendocrine cells (EEC), whereas serotonin is released from enterochromaffin cells (ECC). The central hypothesis

  4. Potent and Selective BACE-1 Peptide Inhibitors Lower Brain Aβ Levels Mediated by Brain Shuttle Transport

    Directory of Open Access Journals (Sweden)

    Nadine Ruderisch

    2017-10-01

    Full Text Available Therapeutic approaches to fight Alzheimer's disease include anti-Amyloidβ (Aβ antibodies and secretase inhibitors. However, the blood-brain barrier (BBB limits the brain exposure of biologics and the chemical space for small molecules to be BBB permeable. The Brain Shuttle (BS technology is capable of shuttling large molecules into the brain. This allows for new types of therapeutic modalities engineered for optimal efficacy on the molecular target in the brain independent of brain penetrating properties. To this end, we designed BACE1 peptide inhibitors with varying lipid modifications with single-digit picomolar cellular potency. Secondly, we generated active-exosite peptides with structurally confirmed dual binding mode and improved potency. When fused to the BS via sortase coupling, these BACE1 inhibitors significantly reduced brain Aβ levels in mice after intravenous administration. In plasma, both BS and non-BS BACE1 inhibitor peptides induced a significant time- and dose-dependent decrease of Aβ. Our results demonstrate that the BS is essential for BACE1 peptide inhibitors to be efficacious in the brain and active-exosite design of BACE1 peptide inhibitors together with lipid modification may be of therapeutic relevance.

  5. Atrial Natriuretic Peptide (ANP) in early pregnancy is associated with development of preeclampsia in type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2011-01-01

    The vasoactive markers of cardiac overload Atrial Natriuretic Peptide (ANP) and Brain Natriuretic Peptide (BNP) are elevated in preeclampsia. This study documents higher ANP concentrations as early as at 9 weeks in type 1 diabetic women subsequently developing preeclampsia suggesting that preecla......The vasoactive markers of cardiac overload Atrial Natriuretic Peptide (ANP) and Brain Natriuretic Peptide (BNP) are elevated in preeclampsia. This study documents higher ANP concentrations as early as at 9 weeks in type 1 diabetic women subsequently developing preeclampsia suggesting...... that preeclampsia is associated with cardiovascular changes in early pregnancy....

  6. Halobacterium salinarum NRC-1 PeptideAtlas: toward strategies for targeted proteomics and improved proteome coverage.

    Science.gov (United States)

    Van, Phu T; Schmid, Amy K; King, Nichole L; Kaur, Amardeep; Pan, Min; Whitehead, Kenia; Koide, Tie; Facciotti, Marc T; Goo, Young Ah; Deutsch, Eric W; Reiss, David J; Mallick, Parag; Baliga, Nitin S

    2008-09-01

    The relatively small numbers of proteins and fewer possible post-translational modifications in microbes provide a unique opportunity to comprehensively characterize their dynamic proteomes. We have constructed a PeptideAtlas (PA) covering 62.7% of the predicted proteome of the extremely halophilic archaeon Halobacterium salinarum NRC-1 by compiling approximately 636 000 tandem mass spectra from 497 mass spectrometry runs in 88 experiments. Analysis of the PA with respect to biophysical properties of constituent peptides, functional properties of parent proteins of detected peptides, and performance of different mass spectrometry approaches has highlighted plausible strategies for improving proteome coverage and selecting signature peptides for targeted proteomics. Notably, discovery of a significant correlation between absolute abundances of mRNAs and proteins has helped identify low abundance of proteins as the major limitation in peptide detection. Furthermore, we have discovered that iTRAQ labeling for quantitative proteomic analysis introduces a significant bias in peptide detection by mass spectrometry. Therefore, despite identifying at least one proteotypic peptide for almost all proteins in the PA, a context-dependent selection of proteotypic peptides appears to be the most effective approach for targeted proteomics.

  7. A Novel Delivery System for the Controlled Release of Antimicrobial Peptides: Citropin 1.1 and Temporin A

    Directory of Open Access Journals (Sweden)

    Urszula Piotrowska

    2018-05-01

    Full Text Available Antimicrobial peptides (AMPs are prospective therapeutic options for treating multiple-strain infections. However, clinical and commercial development of AMPs has some limitations due to their limited stability, low bioavailability, and potential hemotoxicity. The purpose of this study was to develop new polymeric carriers as highly controlled release devices for amphibian peptides citropin 1.1 (CIT and temporin A (TEMP. The release rate of the active pharmaceutical ingredients (APIs was strongly dependent on the API characteristics and the matrix microstructure. In the current work, we investigated the effect of the polymer microstructure on in vitro release kinetics of AMPs. Non-contact laser profilometry, scanning electron microscopy (SEM, and differential scanning calorimetry (DSC were used to determine the structural changes during matrix degradation. Moreover, geno- and cytotoxicity of the synthesized new carriers were evaluated. The in vitro release study of AMPs from the obtained non-toxic matrices shows that peptides were released with near-zero-order kinetics. The peptide “burst release” effect was not observed. New devices have reached the therapeutic concentration of AMPs within 24 h and maintained it for 28 days. Hence, our results suggest that these polymeric devices could be potentially used as therapeutic options for the treatment of local infections.

  8. Fasting plasma C-peptide, glucagon stimulated plasma C-peptide, and urinary C-peptide in relation to clinical type of diabetes

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Faber, O K

    1989-01-01

    with a fasting plasma C-peptide value less than 0.20 nmol/l, a glucagon stimulated plasma C-peptide value less than 0.32 nmol/l, and a urinary C-peptide value less than 3.1 nmol/l, or less than 0.54 nmol/mmol creatinine/24 h, or less than 5.4 nmol/24 h mainly were Type 1 diabetic patients; while patients with C...

  9. Local myocardial insulin-like growth factor 1 (IGF-1) delivery with biotinylated peptide nanofibers improves cell therapy for myocardial infarction

    Science.gov (United States)

    Davis, Michael E.; Hsieh, Patrick C. H.; Takahashi, Tomosaburo; Song, Qing; Zhang, Shuguang; Kamm, Roger D.; Grodzinsky, Alan J.; Anversa, Piero; Lee, Richard T.

    2006-05-01

    Strategies for cardiac repair include injection of cells, but these approaches have been hampered by poor cell engraftment, survival, and differentiation. To address these shortcomings for the purpose of improving cardiac function after injury, we designed self-assembling peptide nanofibers for prolonged delivery of insulin-like growth factor 1 (IGF-1), a cardiomyocyte growth and differentiation factor, to the myocardium, using a "biotin sandwich" approach. Biotinylated IGF-1 was complexed with tetravalent streptavidin and then bound to biotinylated self-assembling peptides. This biotin sandwich strategy allowed binding of IGF-1 but did not prevent self-assembly of the peptides into nanofibers within the myocardium. IGF-1 that was bound to peptide nanofibers activated Akt, decreased activation of caspase-3, and increased expression of cardiac troponin I in cardiomyocytes. After injection into rat myocardium, biotinylated nanofibers provided sustained IGF-1 delivery for 28 days, and targeted delivery of IGF-1 in vivo increased activation of Akt in the myocardium. When combined with transplanted cardiomyocytes, IGF-1 delivery by biotinylated nanofibers decreased caspase-3 cleavage by 28% and increased the myocyte cross-sectional area by 25% compared with cells embedded within nanofibers alone or with untethered IGF-1. Finally, cell therapy with IGF-1 delivery by biotinylated nanofibers improved systolic function after experimental myocardial infarction, demonstrating how engineering the local cellular microenvironment can improve cell therapy. engineering | maturation | scaffold

  10. [The physiology of glucagon-like peptide-1 and its role in the pathophysiology of type 2 diabetes mellitus].

    Science.gov (United States)

    Escalada, Francisco Javier

    2014-09-01

    The hormone glucagon-like peptide-1 (GLP-1) is synthesized and secreted by L cells in the small intestine in response to food ingestion. After reaching the general circulation it has a half-life of 2-3 minutes due to degradation by the enzyme dipeptidyl peptidase-4. Its physiological role is directed to control plasma glucose concentration, though GLP-1 also plays other different metabolic functions following nutrient absorption. Biological activities of GLP-1 include stimulation of insulin biosynthesis and glucose-dependent insulin secretion by pancreatic beta cell, inhibition of glucagon secretion, delay of gastric emptying and inhibition of food intake. GLP-1 is able to reduce plasma glucose levels in patients with type 2 diabetes and also can restore beta cell sensitivity to exogenous secretagogues, suggesting that the increasing GLP-1 concentration may be an useful therapeutic strategy for the treatment of patients with type 2 diabetes. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  11. Comparative mode of action of novel hybrid peptide CS-1a and its rearranged amphipathic analogue CS-2a.

    Science.gov (United States)

    Joshi, Seema; Bisht, Gopal S; Rawat, Diwan S; Maiti, Souvik; Pasha, Santosh

    2012-10-01

    Cell selective, naturally occurring, host defence cationic peptides present a good template for the design of novel peptides with the aim of achieving a short length with improved antimicrobial potency and selectivity. A novel, short peptide CS-1a (14 residues) was derived using a sequence hybridization approach on sarcotoxin I (39 residues) and cecropin B (35 residues). The sequence of CS-1a was rearranged to enhance amphipathicity with the help of a Schiffer-Edmundson diagram to obtain CS-2a. Both peptides showed good antibacterial activity in the concentration range 4-16 μg·mL(-1) against susceptible as well as drug-resistant bacterial strains, including the clinically relevant pathogens Acenatobacter sp. and methicillin-resistant Staphylococcus aureus. The major thrust of these peptides is their nonhaemolytic activity against human red blood cells up to a high concentration of 512 μg·mL(-1). Compared to CS-1a, amphipathic peptide CS-2a showed a more pronounced α-helical conformation, along with a better membrane insertion depth in bacterial mimic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) small unilamellar vesicles. With equivalent lipid-binding affinity, the two peptides assumed different pathways of membrane disruption, as demonstrated by calcein leakage and the results of transmission electron microscopy on model bacterial mimic large unilamellar vesicles. Extending the work from model membranes to intact Escherichia coli cells, differences in membrane perturbation were visible in microscopic images of peptide-treated E. coli. The present study describes two novel short peptides with potent activity, cell selectivity and divergent modes of action that will aid in the future design of peptides with better therapeutic potential. © 2012 The Authors Journal compilation © 2012 FEBS.

  12. Unprecedented high insulin secretion in a healthy human subject after intravenous glucagon-like peptide-1

    DEFF Research Database (Denmark)

    Knop, Filip K; Lund, Asger; Madsbad, Sten

    2014-01-01

    BACKGROUND: The gut-derived incretin hormones, glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1, are released in response to ingestion of nutrients. Both hormones are highly insulinotropic in strictly glucose-dependent fashions and glucagon-like peptide-1 is often referred...... to as one of the most insulinotropic substances known. CASE PRESENTATION: Plasma insulin and C-peptide concentrations were measured in a healthy Caucasian male (age: 53 years; body mass index: 28.6 kg/m2; fasting plasma glucose: 5.7 mM; 2 h plasma glucose value following 75 g-oral glucose tolerance test: 3...

  13. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    International Nuclear Information System (INIS)

    Kim, Sun Young; Song, Kyung-A; Kieff, Elliott; Kang, Myung-Soo

    2012-01-01

    Highlights: ► Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. ► A small molecule and a peptide as EBNA1 dimerization inhibitors identified. ► Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. ► Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)’s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459–607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-Jκ binding to the Jκ site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560–574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated with EBNA1 in vitro, and repressed EBNA1-dependent transcription in vivo. Collectively, this study describes two

  14. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Young; Song, Kyung-A [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kieff, Elliott [Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Kang, Myung-Soo, E-mail: mkang@skku.edu [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated

  15. Lipid raft-like liposomes used for targeted delivery of a chimeric entry-inhibitor peptide with anti-HIV-1 activity.

    Science.gov (United States)

    Gómara, María José; Pérez-Pomeda, Ignacio; Gatell, José María; Sánchez-Merino, Victor; Yuste, Eloisa; Haro, Isabel

    2017-02-01

    The work reports the design and synthesis of a chimeric peptide that is composed of the peptide sequences of two entry inhibitors which target different sites of HIV-1 gp41. The chimeric peptide offers the advantage of targeting two gp41 regions simultaneously: the fusion peptide and the loop both of which are membrane active and participate in the membrane fusion process. We therefore use lipid raft-like liposomes as a tool to specifically direct the chimeric inhibitor peptide to the membrane domains where the HIV-1 envelope protein is located. Moreover, the liposomes that mimic the viral membrane composition protect the chimeric peptide against proteolytic digestion thereby increasing the stability of the peptide. The described liposome preparations are suitable nanosystems for managing hydrophobic entry-inhibitor peptides as putative therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. CD1d-Restricted Type II NKT Cells Reactive With Endogenous Hydrophobic Peptides.

    Science.gov (United States)

    Nishioka, Yusuke; Masuda, Sakiko; Tomaru, Utano; Ishizu, Akihiro

    2018-01-01

    NKT cells belong to a distinct subset of T cells that recognize hydrophobic antigens presented by major histocompatibility complex class I-like molecules, such as CD1d. Because NKT cells stimulated by antigens can activate or suppress other immunocompetent cells through an immediate production of a large amount of cytokines, they are regarded as immunological modulators. CD1d-restricted NKT cells are classified into two subsets, namely, type I and type II. CD1d-restricted type I NKT cells express invariant T cell receptors (TCRs) and react with lipid antigens, including the marine sponge-derived glycolipid α-galactosylceramide. On the contrary, CD1d-restricted type II NKT cells recognize a wide variety of antigens, including glycolipids, phospholipids, and hydrophobic peptides, by their diverse TCRs. In this review, we focus particularly on CD1d-restricted type II NKT cells that recognize endogenous hydrophobic peptides presented by CD1d. Previous studies have demonstrated that CD1d-restricted type I NKT cells usually act as pro-inflammatory cells but sometimes behave as anti-inflammatory cells. It has been also demonstrated that CD1d-restricted type II NKT cells play opposite roles to CD1d-restricted type I NKT cells; thus, they function as anti-inflammatory or pro-inflammatory cells depending on the situation. In line with this, CD1d-restricted type II NKT cells that recognize type II collagen peptide have been demonstrated to act as anti-inflammatory cells in diverse inflammation-induction models in mice, whereas pro-inflammatory CD1d-restricted type II NKT cells reactive with sterol carrier protein 2 peptide have been demonstrated to be involved in the development of small vessel vasculitis in rats.

  17. Effect of a Fusion Peptide by Covalent Conjugation of a Mitochondrial Cell-Penetrating Peptide and a Glutathione Analog Peptide

    Directory of Open Access Journals (Sweden)

    Carmine Pasquale Cerrato

    2017-06-01

    Full Text Available Previously, we designed and synthesized a library of mitochondrial antioxidative cell-penetrating peptides (mtCPPs superior to the parent peptide, SS31, to protect mitochondria from oxidative damage. A library of antioxidative glutathione analogs called glutathione peptides (UPFs, exceptional in hydroxyl radical elimination compared with glutathione, were also designed and synthesized. Here, a follow-up study is described, investigating the effects of the most promising members from both libraries on reactive oxidative species scavenging ability. None of the peptides influenced cell viability at the concentrations used. Fluorescence microscopy studies showed that the fluorescein-mtCPP1-UPF25 (mtgCPP internalized into cells, and spectrofluorometric analysis determined the presence and extent of peptide into different cell compartments. mtgCPP has superior antioxidative activity compared with mtCPP1 and UPF25 against H2O2 insult, preventing ROS formation by 2- and 3-fold, respectively. Moreover, we neither observed effects on mitochondrial membrane potential nor production of ATP. These data indicate that mtgCPP is targeting mitochondria, protecting them from oxidative damage, while also being present in the cytosol. Our hypothesis is based on a synergistic effect resulting from the fused peptide. The mitochondrial peptide segment is targeting mitochondria, whereas the glutathione analog peptide segment is active in the cytosol, resulting in increased scavenging ability.

  18. Read-through transcript from NM23-H1 into the neighboring NM23-H2 gene encodes a novel protein, NM23-LV

    NARCIS (Netherlands)

    Valentijn, Linda J.; Koster, Jan; Versteeg, Rogier

    2006-01-01

    NM23-H1 and NM23-H2 are neighboring genes on chromosome 17q. They encode nucleoside diphosphate kinases that have additional roles in signal transduction, transcription, and apoptosis. NM23-H1 expression is a strong marker for prognosis and metastatic behavior in many tumor types. A new

  19. Peptide ligands for targeting the extracellular domain of EGFR: Comparison between linear and cyclic peptides.

    Science.gov (United States)

    Williams, Tyrslai M; Sable, Rushikesh; Singh, Sitanshu; Vicente, Maria Graca H; Jois, Seetharama D

    2018-02-01

    Colorectal cancer (CRC) is the third most common solid internal malignancy among cancers. Early detection of cancer is key to increasing the survival rate of colorectal cancer patients. Overexpression of the EGFR protein is associated with CRC. We have designed a series of peptides that are highly specific for the extracellular domain of EGFR, based on our earlier studies on linear peptides. The previously reported linear peptide LARLLT, known to bind to EGFR, was modified with the goals of increasing its stability and its specificity toward EGFR. Peptide modifications, including D-amino acid substitution, cyclization, and chain reversal, were investigated. In addition, to facilitate labeling of the peptide with a fluorescent dye, an additional lysine residue was introduced onto the linear (KLARLLT) and cyclic peptides cyclo(KLARLLT) (Cyclo.L1). The lysine residue was also converted into an azide group in both a linear and reversed cyclic peptide sequences cyclo(K(N3)larllt) (Cyclo.L1.1) to allow for subsequent "click" conjugation. The cyclic peptides showed enhanced binding to EGFR by SPR. NMR and molecular modeling studies suggest that the peptides acquire a β-turn structure in solution. In vitro stability studies in human serum show that the cyclic peptide is more stable than the linear peptide. © 2017 John Wiley & Sons A/S.

  20. Peptide immunisation of HLA-DR-transgenic mice permits the identification of a novel HLA-DRbeta1*0101- and HLA-DRbeta1*0401-restricted epitope from p53.

    Science.gov (United States)

    Rojas, José Manuel; McArdle, Stephanie E B; Horton, Roger B V; Bell, Matthew; Mian, Shahid; Li, Geng; Ali, Selman A; Rees, Robert C

    2005-03-01

    Because of the central role of CD4(+) T cells in antitumour immunity, the identification of the MHC class II-restricted peptides to which CD4(+) T cells respond has become a priority of tumour immunologists. Here, we describe a strategy permitting us to rapidly determine the immunogenicity of candidate HLA-DR-restricted peptides using peptide immunisation of HLA-DR-transgenic mice, followed by assessment of the response in vitro. This strategy was successfully applied to the reported haemaglutinin influenza peptide HA(307-319), and then extended to three candidate HLA-DR-restricted p53 peptides predicted by the evidence-based algorithm SYFPEITHI to bind to HLA-DRbeta1*0101 (HLA-DR1) and HLA-DRbeta1*0401 (HLA-DR4) molecules. One of these peptides, p53(108-122), consistently induced responses in HLA-DR1- and in HLA-DR4-transgenic mice. Moreover, this peptide was naturally processed by dendritic cells (DCs), and induced specific proliferation in the splenocytes of mice immunised with p53 cDNA, demonstrating that immune responses could be naturally mounted to the peptide. Furthermore, p53(108-122) peptide was also immunogenic in HLA-DR1 and HLA-DR4 healthy donors. Thus, the use of this transgenic model permitted the identification of a novel HLA-DR-restricted epitope from p53 and constitutes an attractive approach for the rapid identification of novel immunogenic MHC class II-restricted peptides from tumour antigens, which can ultimately be incorporated in immunotherapeutic protocols.

  1. Turn stability in beta-hairpin peptides: Investigation of peptides containing 3:5 type I G1 bulge turns.

    Science.gov (United States)

    Blandl, Tamas; Cochran, Andrea G; Skelton, Nicholas J

    2003-02-01

    The turn-forming ability of a series of three-residue sequences was investigated by substituting them into a well-characterized beta-hairpin peptide. The starting scaffold, bhpW, is a disulfide-cyclized 10-residue peptide that folds into a stable beta-hairpin with two antiparallel strands connected by a two-residue reverse turn. Substitution of the central two residues with the three-residue test sequences leads to less stable hairpins, as judged by thiol-disulfide equilibrium measurements. However, analysis of NMR parameters indicated that each molecule retains a significant folded population, and that the type of turn adopted by the three-residue sequence is the same in all cases. The solution structure of a selected peptide with a PDG turn contained an antiparallel beta-hairpin with a 3:5 type I + G1 bulge turn. Analysis of the energetic contributions of individual turn residues in the series of peptides indicates that substitution effects have significant context dependence, limiting the predictive power of individual amino acid propensities for turn formation. The most stable and least stable sequences were also substituted into a more stable disulfide-cyclized scaffold and a linear beta-hairpin scaffold. The relative stabilities remained the same, suggesting that experimental measurements in the bhpW context are a useful way to evaluate turn stability for use in protein design projects. Moreover, these scaffolds are capable of displaying a diverse set of turns, which can be exploited for the mimicry of protein loops or for generating libraries of reverse turns.

  2. The influence of body mass index and age on C-peptide at the diagnosis of type 1 diabetes in children who participated in the diabetes prevention trial-type 1.

    Science.gov (United States)

    Sosenko, Jay M; Geyer, Susan; Skyler, Jay S; Rafkin, Lisa E; Ismail, Heba M; Libman, Ingrid M; Liu, Yuk-Fun; DiMeglio, Linda A; Evans-Molina, Carmella; Palmer, Jerry P

    2018-05-01

    The extent of influence of BMI and age on C-peptide at the diagnosis of type 1 diabetes (T1D) is unknown. We thus studied the impact of body mass index Z-scores (BMIZ) and age on C-peptide measures at and soon after the diagnosis of T1D. Data from Diabetes Prevention Trial-Type 1 (DPT-1) participants C-peptide measures with BMIZ and age in 2 cohorts: oral glucose tolerance tests (OGTTs) at diagnosis (n = 99) and mixed meal tolerance tests (MMTTs) C-peptide from OGTTs (n = 99) at diagnosis and MMTTs (n = 80) after diagnosis were positively associated with BMIZ and age (P C-peptide measures. In an example, 2 individuals with identical AUC C-peptide values had an approximate 5-fold difference in values after adjustments for BMIZ and age. The association between fasting glucose and C-peptide decreased markedly when fasting C-peptide values were adjusted (r = 0.30, P C-peptide measures are strongly and independently related to BMIZ and age at and soon after the diagnosis of T1D. Adjustments for BMIZ and age cause substantial changes in C-peptide values, and impact the association between glycemia and C-peptide. Such adjustments can improve assessments of β-cell impairment at diagnosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Peptides. Chemistry and Biology: Proceedings of the American Peptide Symposium (12th) Held in Cambridge, Massachusetts on 16-21 June 1991.

    Science.gov (United States)

    1992-01-01

    the aspartimide-containing peptides with aqueous base (0.1 M NH 4OH, I h, 23QC) completely hydrolyzed the aspartimide to yield both the a and...C8, 127.4 and 7-nitro: C5, 130.5: C8 121.8) [4]. The N-acetvl group in each isomer was hydrolyzed (conc. HCI) and each of the free amine was...were transporters of Ca in vesicles made of DMPC, or egg lecithin . The method used in the binding studies was mainly CD which showed substantial

  4. Structure-Based Design of Peptidic Inhibitors of the Interaction between CC Chemokine Ligand 5 (CCL5) and Human Neutrophil Peptides 1 (HNP1)

    NARCIS (Netherlands)

    Wichapong, Kanin; Alard, Jean-Eric; Ortega-Gomez, Almudena; Weber, Christian; Hackeng, Tilman M.; Soehnlein, Oliver; Nicolaes, Gerry A. F.

    2016-01-01

    Protein-protein interactions (PPIs) are receiving increasing interest, much sparked by the realization that they represent druggable targets. Recently, we successfully developed a peptidic inhibitor, RRYGTSKYQ ("SKY" peptide), that shows high potential in vitro and in vivo to interrupt a PPI between

  5. Changes in RFamide-Related Peptide-1 (RFRP-1)-Immunoreactivity During Postnatal Development and the Estrous Cycle

    DEFF Research Database (Denmark)

    Jørgensen, Sara R; Andersen, Mille D; Overgaard, Agnete

    2014-01-01

    and inhibit GnRH neurons. The RFRP precursor is processed into 2 mature peptides, RFRP-1 and RFRP-3. These are characterized by a conserved C-terminal motif RF-NH2 but display highly different N termini. Even though the 2 peptides are equally potent in vitro, little is known about their relative distribution...... and their distinct roles in vivo. In this study, we raised an antiserum selective for RFRP-1 and defined the distribution of RFRP-1-immunoreactive (ir) neurons in the rat brain. Next, we analyzed the level of RFRP-1-ir during postnatal development in males and females and investigated changes in RFRP-1-ir during....... The number of RFRP-1-ir neurons and the density of cellular immunoreactivity were unchanged from juvenile to adulthood in male rats during the postnatal development. However, both parameters were significantly increased in female rats from peripuberty to adulthood, demonstrating prominent gender difference...

  6. Design and synthesis of multiple antigenic peptides and their application for dengue diagnosis.

    Science.gov (United States)

    Rai, Reeta; Dubey, Sameer; Santosh, K V; Biswas, Ashutosh; Mehrotra, Vinit; Rao, D N

    2017-09-01

    Major difficulty in development of dengue diagnostics is availability of suitable antigens. To overcome this, we made an attempt to develop a peptide based diagnosis which offers significant advantage over other methods. With the help of in silico methods, two epitopes were selected from envelope protein and three from NS1 protein of dengue virus. These were synthesized in combination as three multiple antigenic peptides (MAPs). We have tested 157 dengue positive sera confirmed for NS1 antigen. MAP1 showed 96.81% sera positive for IgM and 68.15% positive for IgG. MAP2 detected 94.90% IgM and 59.23% IgG positive sera. MAP3 also detected 96.17% IgM and 59.87% IgG positive sera. To the best of our knowledge this is the first study describing the use of synthetic multiple antigenic peptides for the diagnosis of dengue infection. This study describes MAPs as a promising tool for the use in serodiagnosis of dengue. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  7. 23 CFR 1313.1 - Scope.

    Science.gov (United States)

    2010-04-01

    ... traffic safety problems resulting from individuals driving motor vehicles while under the influence of... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INCENTIVE GRANT CRITERIA FOR ALCOHOL-IMPAIRED DRIVING PREVENTION PROGRAMS § 1313.1 Scope. This part establishes criteria, in accordance with 23 U.S.C...

  8. A synthetic peptide blocking TRPV1 activation inhibits UV-induced skin responses.

    Science.gov (United States)

    Kang, So Min; Han, Sangbum; Oh, Jang-Hee; Lee, Young Mee; Park, Chi-Hyun; Shin, Chang-Yup; Lee, Dong Hun; Chung, Jin Ho

    2017-10-01

    Transient receptor potential type 1 (TRPV1) can be activated by ultraviolet (UV) irradiation, and mediates UV-induced matrix metalloproteinase (MMP)-1 and proinflammatory cytokines in keratinocytes. Various chemicals and compounds targeting TRPV1 activation have been developed, but are not in clinical use mostly due to their safety issues. We aimed to develop a novel TRPV1-targeting peptide to inhibit UV-induced responses in human skin. We designed and generated a novel TRPV1 inhibitory peptide (TIP) which mimics the specific site in TRPV1 (aa 701-709: Gln-Arg-Ala-Ile-Thr-Ile-Leu-Asp-Thr, QRAITILDT), Thr 705 , and tested its efficacy of blocking UV-induced responses in HaCaT, mouse, and human skin. TIP effectively inhibited capsaicin-induced calcium influx and TRPV1 activation. Treatment of HaCaT with TIP prevented UV-induced increases of MMP-1 and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-α. In mouse skin in vivo, TIP inhibited UV-induced skin thickening and prevented UV-induced expression of MMP-13 and MMP-9. Moreover, TIP attenuated UV-induced erythema and the expression of MMP-1, MMP-2, IL-6, and IL-8 in human skin in vivo. The novel synthetic peptide targeting TRPV1 can ameliorate UV-induced skin responses in vitro and in vivo, providing a promising therapeutic approach against UV-induced inflammation and photoaging. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  9. Chimeric mitochondrial peptides from contiguous regular and swinger RNA.

    Science.gov (United States)

    Seligmann, Hervé

    2016-01-01

    Previous mass spectrometry analyses described human mitochondrial peptides entirely translated from swinger RNAs, RNAs where polymerization systematically exchanged nucleotides. Exchanges follow one among 23 bijective transformation rules, nine symmetric exchanges (X ↔ Y, e.g. A ↔ C) and fourteen asymmetric exchanges (X → Y → Z → X, e.g. A → C → G → A), multiplying by 24 DNA's protein coding potential. Abrupt switches from regular to swinger polymerization produce chimeric RNAs. Here, human mitochondrial proteomic analyses assuming abrupt switches between regular and swinger transcriptions, detect chimeric peptides, encoded by part regular, part swinger RNA. Contiguous regular- and swinger-encoded residues within single peptides are stronger evidence for translation of swinger RNA than previously detected, entirely swinger-encoded peptides: regular parts are positive controls matched with contiguous swinger parts, increasing confidence in results. Chimeric peptides are 200 × rarer than swinger peptides (3/100,000 versus 6/1000). Among 186 peptides with > 8 residues for each regular and swinger parts, regular parts of eleven chimeric peptides correspond to six among the thirteen recognized, mitochondrial protein-coding genes. Chimeric peptides matching partly regular proteins are rarer and less expressed than chimeric peptides matching non-coding sequences, suggesting targeted degradation of misfolded proteins. Present results strengthen hypotheses that the short mitogenome encodes far more proteins than hitherto assumed. Entirely swinger-encoded proteins could exist.

  10. 1,1′-(Ethane-1,2-diylbis(indoline-2,3-dione

    Directory of Open Access Journals (Sweden)

    Yao Wang

    2010-07-01

    Full Text Available The molecule of the title compound, C18H12N2O4, is situated on a crystallographic centre of symmetry. The molecule has a zigzag structure, with two parallel symmetry-related indoline-2,3-dione fragments linked by an ethylene group at each N atom. In the crystal, the molecules stack in columns along the b axis. There are two such columns in the structure. The molecules within each column are parallel; however, the molecules in the two columns differ in the respective orientation of the indoline-2,3-dione fragments. In one column, they are approximately parallel to (112, while in the other they are approximately parallel to (overline{1}12. The interplanar angle between the indoline-2,3-dione fragments in the two columns is 80.83 (3°. The molecules within each column are related by mutual displacement of their centres of symmetry, that is (0, ±1/2, ±1/2. The packing between the molecules is provided by weak interactions only, viz. C—H...O hydrogen bonds and π–π [centroid–centroid distance = 3.8745 (8 Å] and C=O...π interactions.

  11. 26 CFR 1.23-4 - Performance and quality standards. [Reserved

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Performance and quality standards. [Reserved] 1.23-4 Section 1.23-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY INCOME TAX INCOME TAXES Changes in Rates During A Taxable Year § 1.23-4 Performance and quality standards. [Reserved...

  12. Role of Glucagon-Like Peptide-1 and Gastric Inhibitory Peptide in Anorexia Induction Following Oral Exposure to the Trichothecene Mycotoxin Deoxynivalenol (Vomitoxin).

    Science.gov (United States)

    Jia, Hui; Wu, Wen-Da; Lu, Xi; Zhang, Jie; He, Cheng-Hua; Zhang, Hai-Bin

    2017-09-01

    Deoxynivalenol (DON), which is a Type B trichothecene mycotoxin produced by Fusarium, frequently contaminates cereal staples, such as wheat, barley and corn. DON threatens animal and human health by suppressing food intake and impairing growth. While anorexia induction in mice exposed to DON has been linked to the elevation of the satiety hormones cholecystokinin and peptide YY3-36 in plasma, the effects of DON on the release of other satiety hormones, such as glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), have not been established. The purpose of this study was to determine the roles of GLP-1 and GIP in DON-induced anorexia. In a nocturnal mouse food consumption model, the elevation of plasma GLP-1 and GIP concentrations markedly corresponded to anorexia induction by DON. Pretreatment with the GLP-1 receptor antagonist Exendin9-39 induced a dose-dependent attenuation of both GLP-1- and DON-induced anorexia. In contrast, the GIP receptor antagonist Pro3GIP induced a dose-dependent attenuation of both GIP- and DON-induced anorexia. Taken together, these results suggest that GLP-1 and GIP play instrumental roles in anorexia induction following oral exposure to DON, and the effect of GLP-1 is more potent and long-acting than that of GIP. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Structure of genes for dermaseptins B, antimicrobial peptides from frog skin. Exon 1-encoded prepropeptide is conserved in genes for peptides of highly different structures and activities.

    Science.gov (United States)

    Vouille, V; Amiche, M; Nicolas, P

    1997-09-01

    We cloned the genes of two members of the dermaseptin family, broad-spectrum antimicrobial peptides isolated from the skin of the arboreal frog Phyllomedusa bicolor. The dermaseptin gene Drg2 has a 2-exon coding structure interrupted by a small 137-bp intron, wherein exon 1 encoded a 22-residue hydrophobic signal peptide and the first three amino acids of the acidic propiece; exon 2 contained the 18 additional acidic residues of the propiece plus a typical prohormone processing signal Lys-Arg and a 32-residue dermaseptin progenitor sequence. The dermaseptin genes Drg2 and Drg1g2 have conserved sequences at both untranslated ends and in the first and second coding exons. In contrast, Drg1g2 comprises a third coding exon for a short version of the acidic propiece and a second dermaseptin progenitor sequence. Structural conservation between the two genes suggests that Drg1g2 arose recently from an ancestral Drg2-like gene through amplification of part of the second coding exon and 3'-untranslated region. Analysis of the cDNAs coding precursors for several frog skin peptides of highly different structures and activities demonstrates that the signal peptides and part of the acidic propieces are encoded by conserved nucleotides encompassed by the first coding exon of the dermaseptin genes. The organization of the genes that belong to this family, with the signal peptide and the progenitor sequence on separate exons, permits strikingly different peptides to be directed into the secretory pathway. The recruitment of such a homologous 'secretory' exon by otherwise non-homologous genes may have been an early event in the evolution of amphibian.

  14. C-Peptide Decline in Type 1 Diabetes Has Two Phases: An Initial Exponential Fall and a Subsequent Stable Phase.

    Science.gov (United States)

    Shields, Beverley M; McDonald, Timothy J; Oram, Richard; Hill, Anita; Hudson, Michelle; Leete, Pia; Pearson, Ewan R; Richardson, Sarah J; Morgan, Noel G; Hattersley, Andrew T

    2018-06-07

    The decline in C-peptide in the 5 years after diagnosis of type 1 diabetes has been well studied, but little is known about the longer-term trajectory. We aimed to examine the association between log-transformed C-peptide levels and the duration of diabetes up to 40 years after diagnosis. We assessed the pattern of association between urinary C-peptide/creatinine ratio (UCPCR) and duration of diabetes in cross-sectional data from 1,549 individuals with type 1 diabetes using nonlinear regression approaches. Findings were replicated in longitudinal follow-up data for both UCPCR ( n = 161 individuals, 326 observations) and plasma C-peptide ( n = 93 individuals, 473 observations). We identified two clear phases of C-peptide decline: an initial exponential fall over 7 years (47% decrease/year [95% CI -51%, -43%]) followed by a stable period thereafter (+0.07%/year [-1.3, +1.5]). The two phases had similar durations and slopes in patients above and below the median age at diagnosis (10.8 years), although levels were lower in the younger patients irrespective of duration. Patterns were consistent in both longitudinal UCPCR ( n = 162; ≤7 years duration: -48%/year [-55%, -38%]; >7 years duration -0.1% [-4.1%, +3.9%]) and plasma C-peptide ( n = 93; >7 years duration only: -2.6% [-6.7%, +1.5%]). These data support two clear phases of C-peptide decline: an initial exponential fall over a 7-year period, followed by a prolonged stabilization where C-peptide levels no longer decline. Understanding the pathophysiological and immunological differences between these two phases will give crucial insights into understanding β-cell survival. © 2018 by the American Diabetes Association.

  15. Glucagon-like peptide-1 receptor ligand interactions: structural cross talk between ligands and the extracellular domain.

    Directory of Open Access Journals (Sweden)

    Graham M West

    Full Text Available Activation of the glucagon-like peptide-1 receptor (GLP-1R in pancreatic β-cells potentiates insulin production and is a current therapeutic target for the treatment of type 2 diabetes mellitus (T2DM. Like other class B G protein-coupled receptors (GPCRs, the GLP-1R contains an N-terminal extracellular ligand binding domain. N-terminal truncations on the peptide agonist generate antagonists capable of binding to the extracellular domain, but not capable of activating full length receptor. The main objective of this study was to use Hydrogen/deuterium exchange (HDX to identify how the amide hydrogen bonding network of peptide ligands and the extracellular domain of GLP-1R (nGLP-1R were altered by binding interactions and to then use this platform to validate direct binding events for putative GLP-1R small molecule ligands. The HDX studies presented here for two glucagon-like peptide-1 receptor (GLP-1R peptide ligands indicates that the antagonist exendin-4[9-39] is significantly destabilized in the presence of nonionic detergents as compared to the agonist exendin-4. Furthermore, HDX can detect stabilization of exendin-4 and exendin-4[9-39] hydrogen bonding networks at the N-terminal helix [Val19 to Lys27] upon binding to the N-terminal extracellular domain of GLP-1R (nGLP-1R. In addition we show hydrogen bonding network stabilization on nGLP-1R in response to ligand binding, and validate direct binding events with the extracellular domain of the receptor for putative GLP-1R small molecule ligands.

  16. Determination of antioxidant activity of bioactive peptide fractions obtained from yogurt.

    Science.gov (United States)

    Aloğlu, H Sanlıdere; Oner, Z

    2011-11-01

    In this study, physicochemical and microbiological properties of traditional and commercial yogurt samples were determined during 4 wk of storage. Proteolytic activity, which occurs during the storage period of yogurt samples, was also determined. Peptide fractions obtained from yogurts were investigated and the effect of proteolysis on peptide release during storage was determined. The antioxidant activities of peptides released from yogurt water-soluble extracts (WSE) and from HPLC fractions were determined by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The antioxidant activity of WSE from traditional yogurt was greater than that of WSE from commercial yogurts. In analysis by the ABTS method, mean values increased from 7.697 to 8.739 mM Trolox/g in commercial yogurts, and from 10.115 to 13.182 mM Trolox/g in traditional yogurts during storage. Antioxidant activities of peptides released from HPLC fractions of selected yogurt samples increased 10 to 200 times. In all yogurt samples, the greatest antioxidant activity was shown in the F2 fraction. After further fractionation of yogurt samples, the fractions coded as F2.2, F2.3, F4.3, and F4.4 had the highest antioxidant activity values. Total antioxidant activity of yogurts was low but after purification of peptides by fractionation in HPLC, peptide fractions with high antioxidant activity were obtained. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Selective peptide bond hydrolysis of cysteine peptides in the presence of Ni(II) ions.

    Science.gov (United States)

    Protas, Anna Maria; Bonna, Arkadiusz; Kopera, Edyta; Bal, Wojciech

    2011-01-01

    Recently, we described a sequence-specific R1-(Ser/Thr) peptide bond hydrolysis reaction in peptides of a general sequence R1-(Ser/Thr)-Xaa-His-Zaa-R, which occurs in the presence of Ni(II) ions [A. Krężel, E. Kopera, A. M. Protas, A. Wysłouch-Cieszyńska, J. Poznański, W. Bal, J. Am. Chem. Soc. 132 (2010) 3355-3366]. In this study we explored the possibility of substituting the Ser/Thr and the His residues, necessary for the reaction to occur according to the Ni(II)-assisted acyl shift reaction mechanism, with Cys residues. We tested this concept by synthesizing three homologous peptides: R1-Ser-Arg-Cys-Trp-R2, R1-Cys-Arg-His-Trp-R2, and R1-Cys-Arg-Cys-Trp-R2, and the R1-Ser-Arg-His-Trp-R2 peptide as comparator (R1 and R2 were CH3CO-Gly-Ala and Lys-Phe-Leu-NH2, respectively). We studied their hydrolysis in the presence of Ni(II) ions, under anaerobic conditions and in the presence of TCEP as a thiol group antioxidant. We measured hydrolysis rates using HPLC and identified products of reaction using electrospray mass spectrometry. Potentiometry and UV-vis spectroscopy were used to assess Ni(II) complexation. We demonstrated that Ni(II) is not compatible with the Cys substitution of the Ser/Thr acyl acceptor residue, but the substitution of the Ni(II) binding His residue with a Cys yields a peptide susceptible to Ni(II)-related hydrolysis. The relatively high activity of the R1-Ser-Arg-Cys-Trp-R2 peptide at pH 7.0 suggests that this peptide and its Cys-containing analogs might be useful in practical applications of Ni(II)-dependent peptide bond hydrolysis. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Endogenous collagen peptide activation of CD1d-restricted NKT cells ameliorates tissue-specific inflammation in mice

    DEFF Research Database (Denmark)

    Liu, Yawei; Teige, Anna; Mondoc, Emma

    2011-01-01

    NKT cells in the mouse recognize antigen in the context of the MHC class I-like molecule CD1d and play an important role in peripheral tolerance and protection against autoimmune and other diseases. NKT cells are usually activated by CD1d-presented lipid antigens. However, peptide recognition...... in the context of CD1 has also been documented, although no self-peptide ligands have been reported to date. Here, we have identified an endogenous peptide that is presented by CD1d to activate mouse NKT cells. This peptide, the immunodominant epitope from mouse collagen type II (mCII707-721), was not associated...... with either MHC class I or II. Activation of CD1d-restricted mCII707-721-specific NKT cells was induced via TCR signaling and classical costimulation. In addition, mCII707-721-specific NKT cells induced T cell death through Fas/FasL, in an IL-17A-independent fashion. Moreover, mCII707-721-specific NKT cells...

  19. LX4211 increases serum glucagon-like peptide 1 and peptide YY levels by reducing sodium/glucose cotransporter 1 (SGLT1)-mediated absorption of intestinal glucose.

    Science.gov (United States)

    Powell, David R; Smith, Melinda; Greer, Jennifer; Harris, Angela; Zhao, Sharon; DaCosta, Christopher; Mseeh, Faika; Shadoan, Melanie K; Sands, Arthur; Zambrowicz, Brian; Ding, Zhi-Ming

    2013-05-01

    LX4211 [(2S,3R,4R,5S,6R)-2-(4-chloro-3-(4-ethoxybenzyl)phenyl)-6-(methylthio)tetrahydro-2H-pyran-3,4,5-triol], a dual sodium/glucose cotransporter 1 (SGLT1) and SGLT2 inhibitor, is thought to decrease both renal glucose reabsorption by inhibiting SGLT2 and intestinal glucose absorption by inhibiting SGLT1. In clinical trials in patients with type 2 diabetes mellitus (T2DM), LX4211 treatment improved glycemic control while increasing circulating levels of glucagon-like peptide 1 (GLP-1) and peptide YY (PYY). To better understand how LX4211 increases GLP-1 and PYY levels, we challenged SGLT1 knockout (-/-) mice, SGLT2-/- mice, and LX4211-treated mice with oral glucose. LX4211-treated mice and SGLT1-/- mice had increased levels of plasma GLP-1, plasma PYY, and intestinal glucose during the 6 hours after a glucose-containing meal, as reflected by area under the curve (AUC) values, whereas SGLT2-/- mice showed no response. LX4211-treated mice and SGLT1-/- mice also had increased GLP-1 AUC values, decreased glucose-dependent insulinotropic polypeptide (GIP) AUC values, and decreased blood glucose excursions during the 6 hours after a challenge with oral glucose alone. However, GLP-1 and GIP levels were not increased in LX4211-treated mice and were decreased in SGLT1-/- mice, 5 minutes after oral glucose, consistent with studies linking decreased intestinal SGLT1 activity with reduced GLP-1 and GIP levels 5 minutes after oral glucose. These data suggest that LX4211 reduces intestinal glucose absorption by inhibiting SGLT1, resulting in net increases in GLP-1 and PYY release and decreases in GIP release and blood glucose excursions. The ability to inhibit both intestinal SGLT1 and renal SGLT2 provides LX4211 with a novel dual mechanism of action for improving glycemic control in patients with T2DM.

  20. Oligomerization of a Glucagon-like Peptide 1 Analog: Bridging Experiment and Simulations

    DEFF Research Database (Denmark)

    Frederiksen, Tine Maja; Sønderby, Pernille; Ryberg, Line A.

    2015-01-01

    The glucagon-like peptide 1 (GLP-1) analog, liraglutide, is a GLP-1 agonist and is used in the treatment of type-2 diabetes mellitus and obesity. From a pharmaceutical perspective, it is important to know the oligomerization state of liraglutide with respect to stability. Compared to GLP-1...

  1. Endogenous peptide profile for elucidating biosynthetic processing of the ghrelin precursor.

    Science.gov (United States)

    Tsuchiya, Takashi; Iwakura, Hiroshi; Minamino, Naoto; Kangawa, Kenji; Sasaki, Kazuki

    2017-09-02

    Ghrelin is an orexigenic peptide primarily produced by gastric endocrine cells. The biosynthetic cleavage site of ghrelin has been well documented, but how its downstream region undergoes proteolytic processing remains poorly explored. Here, we provide the first snapshot of endogenous peptides from the ghrelin precursor by profiling the secretopeptidome of cultured mouse ghrelin-producing cells during exocytosis. Mapping of MS/MS sequenced peptides to the precursor highlighted three atypical monobasic processing sites, including the established C-terminus of ghrelin and the N-terminal cleavage site for obestatin, a putative 23-amino-acid C-terminally amidated peptide. However, we found that mouse obestatin does not occur in the form originally reported, but that a different amidation site is used to generate a shorter peptide. These data can be extended to study and characterize the precursor-derived peptides located downstream of ghrelin in different biological contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Dual-purpose linker for alpha helix stabilization and imaging agent conjugation to glucagon-like peptide-1 receptor ligands.

    Science.gov (United States)

    Zhang, Liang; Navaratna, Tejas; Liao, Jianshan; Thurber, Greg M

    2015-02-18

    Peptides display many characteristics of efficient imaging agents such as rapid targeting, fast background clearance, and low non-specific cellular uptake. However, poor stability, low affinity, and loss of binding after labeling often preclude their use in vivo. Using glucagon-like peptide-1 receptor (GLP-1R) ligands exendin and GLP-1 as a model system, we designed a novel α-helix-stabilizing linker to simultaneously address these limitations. The stabilized and labeled peptides showed an increase in helicity, improved protease resistance, negligible loss or an improvement in binding affinity, and excellent in vivo targeting. The ease of incorporating azidohomoalanine in peptides and efficient reaction with the dialkyne linker enable this technique to potentially be used as a general method for labeling α helices. This strategy should be useful for imaging beta cells in diabetes research and in developing and testing other peptide targeting agents.

  3. Monomeric Aβ1–40 and Aβ1–42 Peptides in Solution Adopt Very Similar Ramachandran Map Distributions That Closely Resemble Random Coil

    Science.gov (United States)

    2016-01-01

    The pathogenesis of Alzheimer’s disease is characterized by the aggregation and fibrillation of amyloid peptides1–40 and Aβ1–42 into amyloid plaques. Despite strong potential therapeutic interest, the structural pathways associated with the conversion of monomeric Aβ peptides into oligomeric species remain largely unknown. In particular, the higher aggregation propensity and associated toxicity of Aβ1–42 compared to that of Aβ1–40 are poorly understood. To explore in detail the structural propensity of the monomeric Aβ1–40 and Aβ1–42 peptides in solution, we recorded a large set of nuclear magnetic resonance (NMR) parameters, including chemical shifts, nuclear Overhauser effects (NOEs), and J couplings. Systematic comparisons show that at neutral pH the Aβ1–40 and Aβ1–42 peptides populate almost indistinguishable coil-like conformations. Nuclear Overhauser effect spectra collected at very high resolution remove assignment ambiguities and show no long-range NOE contacts. Six sets of backbone J couplings (3JHNHα, 3JC′C′, 3JC′Hα, 1JHαCα, 2JNCα, and 1JNCα) recorded for Aβ1–40 were used as input for the recently developed MERA Ramachandran map analysis, yielding residue-specific backbone ϕ/ψ torsion angle distributions that closely resemble random coil distributions, the absence of a significantly elevated propensity for β-conformations in the C-terminal region of the peptide, and a small but distinct propensity for αL at K28. Our results suggest that the self-association of Aβ peptides into toxic oligomers is not driven by elevated propensities of the monomeric species to adopt β-strand-like conformations. Instead, the accelerated disappearance of Aβ NMR signals in D2O over H2O, particularly pronounced for Aβ1–42, suggests that intermolecular interactions between the hydrophobic regions of the peptide dominate the aggregation process. PMID:26780756

  4. A Short Peptide That Mimics the Binding Domain of TGF-β1 Presents Potent Anti-Inflammatory Activity.

    Directory of Open Access Journals (Sweden)

    Emília R Vaz

    Full Text Available The transforming growth factor beta 1 (TGF-β1 is a pleiotropic cytokine with multiple roles in development, wound healing, and immune regulation. TGF-β1-mediated immune dysfunction may lead to pathological conditions, such as inflammation. Chronic inflammatory process is characterized by a continuous release of pro-inflammatory cytokines, and the inhibition or the blockage of these cytokines signaling pathways are considered a target treatment. In this context, despite the high numbers of TGF-β-targeted pathways, the inducible regulatory T cells (iTreg to control inflammation seems to be a promising approach. Our aim was to develop novel peptides through phage display (PhD technology that could mimic TGF-β1 function with higher potency. Specific mimetic peptides were obtained through a PhD subtraction strategy from whole cell binding using TGF-β1 recombinant as a competitor during elution step. We have selected a peptide that seems to play an important role on cellular differentiation and modulation of TNF-α and IL-10 cytokines. The synthetic pm26TGF-β1 peptide tested in PBMC significantly down-modulated TNF-α and up-regulated IL-10 responses, leading to regulatory T cells (Treg phenotype differentiation. Furthermore, the synthetic peptide was able to decrease leukocytes rolling in BALB/C mice and neutrophils migration during inflammatory process in C57BL/6 mice. These data suggest that this peptide may be useful for the treatment of inflammatory diseases, especially because it displays potent anti-inflammatory properties and do not exhibit neutrophils' chemoattraction.

  5. Synthesis of fluorescent analogues of relaxin family peptides and their preliminary in vitro and in vivo characterization

    Directory of Open Access Journals (Sweden)

    Linda eChan

    2013-12-01

    Full Text Available Relaxin, a heterodimeric polypeptide hormone, is a key regulator of collagen metabolism and multiple vascular control pathways in humans and rodents. Its actions are mediated via its cognate G-protein-coupled receptor, RXFP1 although it also ‘pharmacologically’ activates RXFP2, the receptor for the related, insulin-like peptide 3 (INSL3, which has specific actions on reproduction and bone metabolism. Therefore, experimental tools to facilitate insights into the distinct biological actions of relaxin and INSL3 are required, particularly for studies of tissues containing both RXFP1 and RXFP2. Here, we chemically functionalized human (H2 relaxin, the RXFP1-selective relaxin analogue H2:A(4-24(F23A, and INSL3 to accommodate a fluorophore without marked reduction in binding or activation propensity. Chemical synthesis of the two chains for each peptide was followed by sequential regioselective formation of their three disulfide bonds. Click chemistry conjugation of Cy5.5 at the B-chain N-terminus, with conservation of the disulfide bonds, yielded the analogues displaying appropriate selective binding affinity and ability to activate RXFP1 and/or RXFP2 in vitro. The in vivo biological activity of Cy5.5-H2 relaxin and Cy5.5-H2:A(4-24(F23A was confirmed in mice, as acute icv infusion of these peptides (but not Cy5.5-INSL3 stimulated water drinking, an established behavioral response elicited by central RXFP1 activation. The central distribution of Cy5.5-conjugated peptides was examined in mice killed 30 min after infusion, revealing fluorescence within brain tissue near-adjacent to the cerebral ventricle walls relative to deeper brain areas. These data will aid the interpretation of behavioral studies. Production of fluorophore-conjugated relaxin family peptides will facilitate future pharmacological studies to probe the function of H2 relaxin/RXFP1 and INSL3/RXFP2 signaling in vivo while tracking their distribution following central or peripheral

  6. Selection of Novel Peptides Homing the 4T1 CELL Line: Exploring Alternative Targets for Triple Negative Breast Cancer.

    Directory of Open Access Journals (Sweden)

    Vera L Silva

    Full Text Available The use of bacteriophages to select novel ligands has been widely explored for cancer therapy. Their application is most warranted in cancer subtypes lacking knowledge on how to target the cancer cells in question, such as the triple negative breast cancer, eventually leading to the development of alternative nanomedicines for cancer therapeutics. Therefore, the following study aimed to select and characterize novel peptides for a triple negative breast cancer murine mammary carcinoma cell line- 4T1. Using phage display, 7 and 12 amino acid random peptide libraries were screened against the 4T1 cell line. A total of four rounds, plus a counter-selection round using the 3T3 murine fibroblast cell line, was performed. The enriched selective peptides were characterized and their binding capacity towards 4T1 tissue samples was confirmed by immunofluorescence and flow cytometry analysis. The selected peptides (4T1pep1 -CPTASNTSC and 4T1pep2-EVQSSKFPAHVS were enriched over few rounds of selection and exhibited specific binding to the 4T1 cell line. Interestingly, affinity to the human MDA-MB-231 cell line was also observed for both peptides, promoting the translational application of these novel ligands between species. Additionally, bioinformatics analysis suggested that both peptides target human Mucin-16. This protein has been implicated in different types of cancer, as it is involved in many important cellular functions. This study strongly supports the need of finding alternative targeting systems for TNBC and the peptides herein selected exhibit promising future application as novel homing peptides for breast cancer therapy.

  7. A novel branched TAT(47-57) peptide for selective Ni(2+) introduction into the human fibrosarcoma cell nucleus.

    Science.gov (United States)

    Szyrwiel, Łukasz; Shimura, Mari; Shirataki, Junko; Matsuyama, Satoshi; Matsunaga, Akihiro; Setner, Bartosz; Szczukowski, Łukasz; Szewczuk, Zbigniew; Yamauchi, Kazuto; Malinka, Wiesław; Chavatte, Laurent; Łobinski, Ryszard

    2015-07-01

    A TAT47-57 peptide was modified on the N-terminus by elongation with a 2,3-diaminopropionic acid residue and then by coupling of two histidine residues on its N-atoms. This branched peptide could bind to Ni under physiological conditions as a 1 : 1 complex. We demonstrated that the complex was quantitatively taken up by human fibrosarcoma cells, in contrast to Ni(2+) ions. Ni localization (especially at the nuclei) was confirmed by imaging using both scanning X-ray fluorescence microscopy and Newport Green fluorescence. A competitive assay with Newport Green showed that the latter displaced the peptide ligand from the Ni-complex. Ni(2+) delivered as a complex with the designed peptide induced substantially more DNA damage than when introduced as a free ion. The availability of such a construct opens up the way to investigate the importance of the nucleus as a target for the cytotoxicity, genotoxicity or carcinogenicity of Ni(2+).

  8. Structure of the antimicrobial beta-hairpin peptide protegrin-1 in a DLPC lipid bilayer investigated by molecular dynamics simulation

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Kaznessis, Yiannis N

    2007-01-01

    -550]), and to delineate specific peptide-membrane interactions which are responsible for the peptide's membrane binding properties. A novel, previously unknown, "kick" shaped conformation of the peptide was detected, where a bend at the C-terminal beta-strand of the peptide caused the peptide backbone at residues 16...... different initial orientations of the peptide converged to the same final equilibrium orientation of the peptide relative to the bilayer. The kick-shaped conformation was observed only in one of the two simulations....... of the peptide in a membrane environment (previously solved only in solution [R.L. Fahrner, T. Dieckmann, S.S.L. Harwig, R.I. Lehrer, D. Eisenberg, J. Feigon, Solution structure of protegrin-1, a broad-spectrum antimicrobial peptide from porcine leukocytes. Chemistry and Biology, 3 (1996) 543...

  9. Extended Release of an Anti–Heparan Sulfate Peptide From a Contact Lens Suppresses Corneal Herpes Simplex Virus-1 Infection

    Science.gov (United States)

    Jaishankar, Dinesh; Buhrman, Jason S.; Valyi-Nagy, Tibor; Gemeinhart, Richard A.; Shukla, Deepak

    2016-01-01

    Purpose To prolong the release of a heparan sulfate binding peptide, G2-C, using a commercially available contact lens as a delivery vehicle and to demonstrate the ability of the released peptide to block herpes simplex virus-1 (HSV-1) infection using in vitro, ex vivo, and in vivo models of corneal HSV-1 infection. Methods Commercially available contact lenses were immersed in peptide solution for 5 days prior to determining the release of the peptide at various time points. Cytotoxicity of the released samples was determined by MTT and cell cycle analysis, and the functional activity of the released samples were assessed by viral entry, and viral spread assay using human corneal epithelial cells (HCE). The ability to suppress infection in human and pig cornea ex vivo and mouse in vivo models were also assessed. Results Peptide G2-C was released through the contact lens. Following release for 3 days, the peptide showed significant activity by inhibiting HSV-1 viral entry and spread in HCE cells. Significant suppression of infection was also observed in the ex vivo and in vivo experiments involving corneas. Conclusions Extended release of an anti–HS peptide through a commercially available contact lens can generate significant anti–HSV-1 activity and provides a new and effective way to control corneal herpes. PMID:26780322

  10. Glucagon-like Peptide-1 and the Central/Peripheral Nervous System

    DEFF Research Database (Denmark)

    Muscogiuri, Giovanna; DeFronzo, Ralph A; Gastaldelli, Amalia

    2017-01-01

    Glucagon-like peptide-1 (GLP-1) is released in response to meals and exerts important roles in the maintenance of normal glucose homeostasis. GLP-1 is also important in the regulation of neurologic and cognitive functions. These actions are mediated via neurons in the nucleus of the solitary trac...... human trials report a neuroprotective effect of GLP-1-RAs in Alzheimer's and Parkinson's disease. In this review, we discuss the role of GLP-1 and GLP-1-RAs in the nervous system with focus on GLP-1 actions on appetite regulation, glucose homeostasis, and neuroprotection....

  11. 1-(3-aminopropyl)-3-butylimidazolium bromide for carboxyl group derivatization: potential applications in high sensitivity peptide identification by mass spectrometry.

    Science.gov (United States)

    Qiao, Xiaoqiang; Zhou, Yuan; Hou, Chunyan; Zhang, Xiaodan; Yang, Kaiguang; Zhang, Lihua; Zhang, Yukui

    2013-03-01

    The cationic reagent 1-(3-aminopropyl)-3-butylimidazolium bromide (BAPI) was exploited for the derivatization of carboxyl groups on peptides. Nearly 100% derivatization efficiency was achieved with the synthetic peptide RVYVHPI (RI-7). Furthermore, the peptide derivative was stable in a 0.1% TFA/water solution or a 0.1% (v/v) TFA/acetonitrile/water solution for at least one week. The effect of BAPI derivatization on the ionization of the peptide RI-7 was further investigated, and the detection sensitivity was improved >42-fold via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), thus outperforming the commercial piperazine derivatization approach. Moreover, the charge states of the peptide were largely increased via BAPI derivatization by electrospray ionization (ESI) MS. The results indicate the potential merits of BAPI derivatization for high sensitivity peptide analysis by MS.

  12. Site-specific Orientation of an α-helical Peptide Ovispirin-1 from Isotope Labeled SFG Spectroscopy

    Science.gov (United States)

    Ding, Bei; Laaser, Jennifer E.; Liu, Yuwei; Wang, Pengrui; Zanni, Martin T.; Chen, Zhan

    2013-01-01

    Sum-frequency generation (SFG) vibrational spectroscopy is often used to probe the backbone structures and orientations of polypeptides at surfaces. Using the ovispirin-1 polypeptide at the solid/liquid interface of polystyrene, we demonstrate for the first time that SFG can probe the polarization response of a single isotope labeled residue. To interpret the spectral intensities, we simulated the spectra using an excitonic Hamiltonian approach. We show that the polarization dependence of either the label or the unlabeled amide I band alone does not provide sufficient structural constraints to obtain both the tilt and the twist of the ovispirin helix at a solid/liquid interface, but that both can be determined from the polarization dependence of the complete spectrum. For ovispirin, the detailed analysis of the polarized SFG experimental data shows that the helix axis is tilted at roughly 138 degrees from the surface normal, and the transition dipole of the isotope labeled C=O group is tilted at 23 degrees from the surface normal, with the hydrophobic region facing the polystyrene surface. We further demonstrated that the Hamiltonian approach is able to address the coupling effect and the structural disorder. For comparison, we also collected the FTIR spectrum of ovispirin under similar conditions, which reveals the enhanced sensitivity of SFG for structural studies of single monolayer peptide surfaces. Our study provides insight into how structural and environmental effects appear in SFG spectra of the amide I band and establishes that SFG of isotope labeled peptides will be a powerful technique for elucidating secondary structures with residue-by-residue resolution. PMID:24228619

  13. Site-specific orientation of an α-helical peptide ovispirin-1 from isotope-labeled SFG spectroscopy.

    Science.gov (United States)

    Ding, Bei; Laaser, Jennifer E; Liu, Yuwei; Wang, Pengrui; Zanni, Martin T; Chen, Zhan

    2013-11-27

    Sum-frequency generation (SFG) vibrational spectroscopy is often used to probe the backbone structures and orientations of polypeptides at surfaces. Using the ovispirin-1 polypeptide at the solid/liquid interface of polystyrene, we demonstrate for the first time that SFG can probe the polarization response of a single-isotope-labeled residue. To interpret the spectral intensities, we simulated the spectra using an excitonic Hamiltonian approach. We show that the polarization dependence of either the label or the unlabeled amide I band alone does not provide sufficient structural constraints to obtain both the tilt and the twist of the ovispirin helix at a solid/liquid interface, but that both can be determined from the polarization dependence of the complete spectrum. For ovispirin, the detailed analysis of the polarized SFG experimental data shows that the helix axis is tilted at roughly 138° from the surface normal, and the transition dipole of the isotope-labeled C═O group is tilted at 23° from the surface normal, with the hydrophobic region facing the polystyrene surface. We further demonstrate that the Hamiltonian approach is able to address the coupling effect and the structural disorder. For comparison, we also collected the FTIR spectrum of ovispirin under similar conditions, which reveals the enhanced sensitivity of SFG for structural studies of single monolayer peptide surfaces. Our study provides insight into how structural and environmental effects appear in SFG spectra of the amide I band and establishes that SFG of isotope-labeled peptides will be a powerful technique for elucidating secondary structures with residue-by-residue resolution.

  14. Physiology and Emerging Biochemistry of the Glucagon-Like Peptide-1 Receptor

    Directory of Open Access Journals (Sweden)

    Francis S. Willard

    2012-01-01

    Full Text Available The glucagon-like peptide-1 (GLP-1 receptor is one of the best validated therapeutic targets for the treatment of type 2 diabetes mellitus (T2DM. Over several years, the accumulation of basic, translational, and clinical research helped define the physiologic roles of GLP-1 and its receptor in regulating glucose homeostasis and energy metabolism. These efforts provided much of the foundation for pharmaceutical development of the GLP-1 receptor peptide agonists, exenatide and liraglutide, as novel medicines for patients suffering from T2DM. Now, much attention is focused on better understanding the molecular mechanisms involved in ligand induced signaling of the GLP-1 receptor. For example, advancements in biophysical and structural biology techniques are being applied in attempts to more precisely determine ligand binding and receptor occupancy characteristics at the atomic level. These efforts should better inform three-dimensional modeling of the GLP-1 receptor that will help inspire more rational approaches to identify and optimize small molecule agonists or allosteric modulators targeting the GLP-1 receptor. This article reviews GLP-1 receptor physiology with an emphasis on GLP-1 induced signaling mechanisms in order to highlight new molecular strategies that help determine desired pharmacologic characteristics for guiding development of future nonpeptide GLP-1 receptor activators.

  15. A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood.

    Science.gov (United States)

    Teuffel, Pauline; Goebel-Stengel, Miriam; Hofmann, Tobias; Prinz, Philip; Scharner, Sophie; Körner, Jan L; Grötzinger, Carsten; Rose, Matthias; Klapp, Burghard F; Stengel, Andreas

    2016-04-28

    Research in the field of food intake regulation is gaining importance. This often includes the measurement of peptides regulating food intake. For the correct determination of a peptide's concentration, it should be stable during blood processing. However, this is not the case for several peptides which are quickly degraded by endogenous peptidases. Recently, we developed a blood processing method employing Reduced temperatures, Acidification, Protease inhibition, Isotopic exogenous controls and Dilution (RAPID) for the use in rats. Here, we have established this technique for the use in humans and investigated recovery, molecular form and circulating concentration of food intake regulatory hormones. The RAPID method significantly improved the recovery for (125)I-labeled somatostatin-28 (+39%), glucagon-like peptide-1 (+35%), acyl ghrelin and glucagon (+32%), insulin and kisspeptin (+29%), nesfatin-1 (+28%), leptin (+21%) and peptide YY3-36 (+19%) compared to standard processing (EDTA blood on ice, p processing, while after standard processing 62% of acyl ghrelin were degraded resulting in an earlier peak likely representing desacyl ghrelin. After RAPID processing the acyl/desacyl ghrelin ratio in blood of normal weight subjects was 1:3 compared to 1:23 following standard processing (p = 0.03). Also endogenous kisspeptin levels were higher after RAPID compared to standard processing (+99%, p = 0.02). The RAPID blood processing method can be used in humans, yields higher peptide levels and allows for assessment of the correct molecular form.

  16. Treating autoimmune disorders with venom-derived peptides.

    Science.gov (United States)

    Shen, Bingzheng; Cao, Zhijian; Li, Wenxin; Sabatier, Jean-Marc; Wu, Yingliang

    2017-09-01

    The effective treatment of autoimmune diseases remains a challenge. Voltage-gated potassium Kv1.3 channels, which are expressed in lymphocytes, are a new therapeutic target for treating autoimmune disease. Consequently, Kv1.3 channel-inhibiting venom-derived peptides are a prospective resource for new drug discovery and clinical application. Area covered: Preclinical and clinical studies have produced a wealth of information on Kv1.3 channel-inhibiting venom-derived peptides, especially from venomous scorpions and sea anemones. This review highlights the advances in screening and design of these peptides with diverse structures and potencies. It focuses on representative strategies for improving peptide selectivity and discusses the preclinical research on those venom-derived peptides as well as their clinical developmental status. Expert opinion: Encouraging results indicate that peptides isolated from the venom of venomous animals are a large resource for discovering immunomodulators that act on Kv1.3 channels. Since the structural diversity of venom-derived peptides determines the variety of their pharmacological activities, the design and optimization of venom-peptides for improved Kv1.3 channel-specificity has been advanced through some representative strategies, such as peptide chemical modification, amino acid residue truncation and binding interface modulation. These advances should further accelerate research, development and the future clinical application of venom-derived peptides selectively targeting Kv1.3 channels.

  17. Meta-genome-wide association studies identify a locus on chromosome 1 and multiple variants in the MHC region for serum C-peptide in type 1 diabetes.

    Science.gov (United States)

    Roshandel, Delnaz; Gubitosi-Klug, Rose; Bull, Shelley B; Canty, Angelo J; Pezzolesi, Marcus G; King, George L; Keenan, Hillary A; Snell-Bergeon, Janet K; Maahs, David M; Klein, Ronald; Klein, Barbara E K; Orchard, Trevor J; Costacou, Tina; Weedon, Michael N; Oram, Richard A; Paterson, Andrew D

    2018-05-01

    The aim of this study was to identify genetic variants associated with beta cell function in type 1 diabetes, as measured by serum C-peptide levels, through meta-genome-wide association studies (meta-GWAS). We performed a meta-GWAS to combine the results from five studies in type 1 diabetes with cross-sectionally measured stimulated, fasting or random C-peptide levels, including 3479 European participants. The p values across studies were combined, taking into account sample size and direction of effect. We also performed separate meta-GWAS for stimulated (n = 1303), fasting (n = 2019) and random (n = 1497) C-peptide levels. In the meta-GWAS for stimulated/fasting/random C-peptide levels, a SNP on chromosome 1, rs559047 (Chr1:238753916, T>A, minor allele frequency [MAF] 0.24-0.26), was associated with C-peptide (p = 4.13 × 10 -8 ), meeting the genome-wide significance threshold (p C>T, MAF 0.07-0.10, p = 8.43 × 10 -8 ). In the stimulated C-peptide meta-GWAS, rs61211515 (Chr6:30100975, T/-, MAF 0.17-0.19) in the MHC region was associated with stimulated C-peptide (β [SE] = - 0.39 [0.07], p = 9.72 × 10 -8 ). rs61211515 was also associated with the rate of stimulated C-peptide decline over time in a subset of individuals (n = 258) with annual repeated measures for up to 6 years (p = 0.02). In the meta-GWAS of random C-peptide, another MHC region, SNP rs3135002 (Chr6:32668439, C>A, MAF 0.02-0.06), was associated with C-peptide (p = 3.49 × 10 -8 ). Conditional analyses suggested that the three identified variants in the MHC region were independent of each other. rs9260151 and rs3135002 have been associated with type 1 diabetes, whereas rs559047 and rs61211515 have not been associated with a risk of developing type 1 diabetes. We identified a locus on chromosome 1 and multiple variants in the MHC region, at least some of which were distinct from type 1 diabetes risk loci, that were associated with C-peptide

  18. Familial isolated clubfoot is associated with recurrent chromosome 17q23.1q23.2 microduplications containing TBX4.

    Science.gov (United States)

    Alvarado, David M; Aferol, Hyuliya; McCall, Kevin; Huang, Jason B; Techy, Matthew; Buchan, Jillian; Cady, Janet; Gonzales, Patrick R; Dobbs, Matthew B; Gurnett, Christina A

    2010-07-09

    Clubfoot is a common musculoskeletal birth defect for which few causative genes have been identified. To identify the genes responsible for isolated clubfoot, we screened for genomic copy-number variants with the Affymetrix Genome-wide Human SNP Array 6.0. A recurrent chromosome 17q23.1q23.2 microduplication was identified in 3 of 66 probands with familial isolated clubfoot. The chromosome 17q23.1q23.2 microduplication segregated with autosomal-dominant clubfoot in all three families but with reduced penetrance. Mild short stature was common and one female had developmental hip dysplasia. Subtle skeletal abnormalities consisted of broad and shortened metatarsals and calcanei, small distal tibial epiphyses, and thickened ischia. Several skeletal features were opposite to those described in the reciprocal chromosome 17q23.1q23.2 microdeletion syndrome associated with developmental delay and cardiac and limb abnormalities. Of note, during our study, we also identified a microdeletion at the locus in a sibling pair with isolated clubfoot. The chromosome 17q23.1q23.2 region contains the T-box transcription factor TBX4, a likely target of the bicoid-related transcription factor PITX1 previously implicated in clubfoot etiology. Our result suggests that this chromosome 17q23.1q23.2 microduplication is a relatively common cause of familial isolated clubfoot and provides strong evidence linking clubfoot etiology to abnormal early limb development. Copyright 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  19. Chenodeoxycholic acid stimulates glucagon-like peptide-1 secretion in patients after Roux-en-Y gastric bypass

    DEFF Research Database (Denmark)

    Nielsen, Signe; Svane, Maria S; Kuhre, Rune E

    2017-01-01

    (BMI 29.1 ± 1.2, age 37.0 ± 3.2 years, time from RYGB 32.3 ± 1.1 months, weight loss after RYGB 37.0 ± 3.1 kg) were studied in a placebo-controlled, crossover-study. On three different days, participants ingested (1) placebo (water), (2) UDCA 750 mg, (3) CDCA 1250 mg (highest recommended doses). Oral...... intake of CDCA increased plasma concentrations of GLP-1, C-peptide, glucagon, peptide YY, neurotensin, total bile acids, and fibroblast growth factor 19 significantly compared with placebo (all P

  20. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

    Science.gov (United States)

    Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B; Jiang, X; Lee, Chang Won; Renukaradhya, Gourapura J

    2016-01-01

    Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  1. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

    Directory of Open Access Journals (Sweden)

    Jagadish Hiremath

    Full Text Available Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV. Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA nanoparticle (PLGA-NP based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2 chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  2. Toward a new and noninvasive diagnostic method of papillary thyroid cancer by using peptide vectorized contrast agents targeted to galectin-1.

    Science.gov (United States)

    Fanfone, Deborah; Despretz, Nadège; Stanicki, Dimitri; Rubio-Magnieto, Jenifer; Fossépré, Mathieu; Surin, Mathieu; Rorive, Sandrine; Salmon, Isabelle; Vander Elst, Luce; Laurent, Sophie; Muller, Robert N; Saussez, Sven; Burtea, Carmen

    2017-10-06

    The incidence of papillary thyroid cancer has increased these last decades due to a better detection. High prevalence of nodules combined with the low incidence of thyroid cancers constitutes an important diagnostic challenge. We propose to develop an alternative diagnostic method to reduce the number of useless and painful thyroidectomies using a vectorized contrast agent for magnetic resonance imaging. Galectin-1 (gal-1), a protein overexpressed in well-differentiated thyroid cancer, has been targeted with a randomized linear 12-mer peptide library using the phage display technique. Selected peptides have been conjugated to ultrasmall superparamagnetic particles of iron oxide (USPIO). Peptides and their corresponding contrast agents have been tested in vitro for their specific binding and toxicity. Two peptides (P1 and P7) were selected according to their affinity toward gal-1. Their binding has been revealed by immunohistochemistry on human thyroid cancer biopsies, and they were co-localized with gal-1 by immunofluorescence on TPC-1 cell line. Both peptides induce a decrease in TPC-1 cells' adhesion to gal-1 immobilized on culture plates. After coupling to USPIO, the peptides preserved their affinity toward gal-1. Their specific binding has been corroborated by co-localization with gal-1 expressed by TPC-1 cells and by their ability to compete with anti-gal-1 antibody. The peptides and their USPIO derivatives produce no toxicity in HepaRG cells as determined by MTT assay. The vectorized contrast agents are potential imaging probes for thyroid cancer diagnosis. Moreover, the two gal-1-targeted peptides prevent cancer cell adhesion by interacting with the carbohydrate-recognition domain of gal-1.

  3. GLP-1 (glucagon-like peptide 1) and truncated GLP-1, fragments of human proglucagon, inhibit gastric acid secretion in humans

    DEFF Research Database (Denmark)

    Schjoldager, B T; Mortensen, P E; Christiansen, J

    1989-01-01

    Glucagon-like peptide 1 amide (GLP-1 amide), a predicted product of the glucagon gene (proglucagon 72-107-amide), and truncated GLP-1 (proglucagon 78-107-amide), recently isolated from porcine small intestine, were infused in doses of 100 and 400 ng/kg/hr and 12.5 and 50 ng/kg/hr, respectively...

  4. Preserved C-peptide levels in overweight or obese compared with underweight children upon diagnosis of type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Hyeoh Won Yu

    2015-06-01

    Full Text Available PurposeWe hypothesized that overweight or obese children might develop type 1 diabetes mellitus (T1DM early despite residual beta-cell function. Factors independently associated with preservation of C-peptide level were analyzed.MethodsWe retrospectively reviewed the medical data of 135 children aged 2.1-16.5 years with autoimmune T1DM. Body mass index (BMI, pubertal stage, and glycosylated hemoglobin (HbA1c and C-peptide levels were evaluated. Patients were assigned to underweight (22.2%, normal weight (63.7%, and overweight or obese (14.1% groups according to their BMI.ResultsPreservation of serum C-peptide levels (≥0.6 ng/mL was found in 43.0% of subjects. With increasing BMI, the proportions of children with preserved C-peptide levels increased from 33.3% to 41.9% to 63.2%, with marginal significance (P=0.051. Interaction analysis indicated no effect of BMI score on age at onset associated with serum C-peptide levels. The lower the C-peptide level, the younger the age of onset (P<0.001, after adjustment for BMI z-score and HbA1c level. However, no significant relationship between BMI z-score or category and onset age was evident. Upon multivariate-adjusted modeling, the odds that the C-peptide level was preserved increased by 1.2 fold (P=0.001 per year of life, by 3.1 folds (P=0.015 in children presenting without (compared to with ketoacidosis, and by 5.0 folds (P=0.042 in overweight or obese (compared to underweight children.ConclusionOverweight or obese children had slightly more residual beta-cell function than did underweight children. However, we found no evidence that obesity temporally accelerates T1DM presentation.

  5. Levels of 25(OHD3, IL-2, and C-peptide in Children with Type 1 Diabetes Mellitus (T1DM Receiving Vitamin D3 Supplementation

    Directory of Open Access Journals (Sweden)

    Tjahyo Suryanto

    2018-01-01

    Full Text Available Type 1 Diabetes Mellitus (T1DM has become a health problem in many countries. T1DM is the consequence of autoimmune destruction process of β cells. There was relationship between vitamin D deficiency with T1DM. The destruction process was caused by an imbalance of pro-inflammatory and anti-inflammatory cytokines. One of the pro-inflammatory cytokines is IL-2. C-peptide examination to see the function of beta cells due to destruction of pancreatic beta cell. Administration of vitamin D3 supplementation still cause controversy and give varying results. This randomized clinical trial was conducted to determine the levels of 25(OHD3, IL-2, and C-peptide in people with T1DM who received vitamin D3 supplementation. The subjects were 26 children with T1DM, divided into K1 group (received vitamin D3 supplementation and K2 group (received placebo. The results showed higher levels of 25(OHD3 in the K1 group and statistically found a significant difference (p = 0.00. Higher levels of IL-2 and lower C-peptide were obtained in the K1 group and no statistically significant differences were found (p = 0.76 and p= 0.26. The insignificant relationship and the negative correlation were found between 25(OHD3 and IL-2 (p = 0.71; r = - 0.12, 25(OHD3 and C-peptide (p = 0.59; r = -0.16, also levels of IL-2 and C-peptide (p = 0.13; r = -0.44 in children with type 1 diabetes who received vitamin D3 supplementation. From this study can be concluded that administration vitamin D3 supplementation in patients with T1DM can increase levels 25(OHD3 significantly. This increase has not significantly lowered levels of IL-2 and increased levels of C-peptide. However, there was an absolute decrease in the rate of slower C-peptide in the supplemented group than in the placebo group.

  6. A Dual-Purpose Linker for Alpha Helix Stabilization and Imaging Agent Conjugation to Glucagon-Like Peptide-1 Receptor Ligands

    Science.gov (United States)

    Zhang, Liang; Navaratna, Tejas; Liao, Jianshan; Thurber, Greg M.

    2016-01-01

    Peptides display many characteristics of efficient imaging agents such as rapid targeting, fast background clearance, and low non-specific cellular uptake. However, poor stability, low affinity, and loss of binding after labeling often preclude their use in vivo. Using the glucagon-like peptide-1 receptor (GLP-1R) ligands exendin and GLP-1 as a model system, we designed a novel alpha helix stabilizing linker to simultaneously address these limitations. The stabilized and labeled peptides showed an increase in helicity, improved protease resistance, negligible loss or an improvement in binding affinity, and excellent in vivo targeting. The ease of incorporating azidohomoalanine in peptides and efficient reaction with the dialkyne linker enables this technique to potentially be used as a general method for labeling alpha helices. This strategy should be useful for imaging beta cells in diabetes research and in developing and testing other peptide targeting agents. PMID:25594741

  7. Novel Naja atra cardiotoxin 1 (CTX-1 derived antimicrobial peptides with broad spectrum activity.

    Directory of Open Access Journals (Sweden)

    Andrea Sala

    Full Text Available Naja atra subsp. atra cardiotoxin 1 (CTX-1, produced by Chinese cobra snakes, belonging to Elapidae family, is included in the three-finger toxin family and exerts high cytotoxicity and antimicrobial activity too. Using as template mainly the tip and the subsequent β-strand of the first "finger" of this toxin, different sequences of 20 amino acids linear peptides have been designed in order to avoid toxic effects but to maintain or even strengthen the partial antimicrobial activity already seen for the complete toxin. As a result, the sequence NCP-0 (Naja Cardiotoxin Peptide-0 was designed as ancestor and subsequently 4 other variant sequences of NCP-0 were developed. These synthesized variant sequences have shown microbicidal activity towards a panel of reference and field strains of Gram-positive and Gram-negative bacteria. The sequence named NCP-3, and its variants NCP-3a and NCP-3b, have shown the best antimicrobial activity, together with low cytotoxicity against eukaryotic cells and low hemolytic activity. Bactericidal activity has been demonstrated by minimum bactericidal concentration (MBC assay at values below 10 μg/ml for most of the tested bacterial strains. This potent antimicrobial activity was confirmed even for unicellular fungi Candida albicans, Candida glabrata and Malassezia pachydermatis (MBC 50-6.3 μg/ml, and against the fast-growing mycobacteria Mycobacterium smegmatis and Mycobacterium fortuitum. Moreover, NCP-3 has shown virucidal activity on Bovine Herpesvirus 1 (BoHV1 belonging to Herpesviridae family. The bactericidal activity is maintained even in a high salt concentration medium (125 and 250 mM NaCl and phosphate buffer with 20% Mueller Hinton (MH medium against E. coli, methicillin resistant Staphylococcus aureus (MRSA and Pseudomonas aeruginosa reference strains. Considering these in vitro obtained data, the search for active sequences within proteins presenting an intrinsic microbicidal activity could provide a

  8. Effects of the antimicrobial peptide protegrine 1 on sperm viability and bacterial load of boar seminal doses.

    Science.gov (United States)

    Sancho, S; Briz, M; Yeste, M; Bonet, S; Bussalleu, E

    2017-10-01

    The presence of bacteria adversely affects boar sperm quality of seminal doses intended for artificial insemination. Currently, the most common measure to prevent bacteriospermia is the addition of antibiotics in semen extenders; however, mounting evidence shows that microbial resistance exists. A promising alternative to replace antibiotics are antimicrobial peptides. In this study, the effects of the antimicrobial peptide protegrine 1 (PG1) on the sperm viability and bacterial load of boar seminal doses were evaluated. Three different concentrations of PG1 (2.5, 25 and 100 μg/ml) were tested over a storing period of 10 days at 17°C. Sperm viability was analysed by fluorescence microscopy (SYBR14/propidium iodide), and bacterial load was assessed by plating 100 μl of each sample in Luria-Bertani medium and incubated at 37°C for 72 hr under aerobic conditions. Protegrine 1 was effective in controlling the bacterial load in all the assessed concentrations (p < .05), reaching the lowest values at the highest concentrations of the antimicrobial peptide. Nevertheless, sperm viability was significantly (p < .05) reduced by all tested concentrations of this peptide, the most cytotoxic effects being observed at the highest PG1 concentrations. Despite these results, the use of PG1 as an alternative to antibiotics cannot be totally discarded, as further studies using the truncated form of this peptide are needed. © 2017 Blackwell Verlag GmbH.

  9. Incretin-based treatment of type 2 diabetes: glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors

    DEFF Research Database (Denmark)

    Deacon, Carolyn F

    2007-01-01

    Incretins are gut peptides that potentiate nutrient-stimulated insulin secretion following meal ingestion. Activities of the dominant incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, include glucose-dependent stimulation of insulin secretion and, in preclin...... and liraglutide) and DPP-4 inhibitors that act to increase concentrations of endogenous intact incretins (e.g. sitagliptin and vildagliptin). Clinical trials of these incretin-based therapies have shown them to be effective in improving glycaemic control in patients with T2DM....

  10. Design and mechanism of action of a novel bacteria-selective antimicrobial peptide from the cell-penetrating peptide Pep-1

    International Nuclear Information System (INIS)

    Zhu, W.L.; Lan Hongliang; Park, Il-Seon; Kim, Jae Il; Jin, H.Z.; Hahm, Kyung-Soo; Shin, S.Y.

    2006-01-01

    Here, we report the successful design of a novel bacteria-selective antimicrobial peptide, Pep-1-K (KKTWWKTWWTKWSQPKKKRKV). Pep-1-K was designed by replacing Glu-2, Glu-6, and Glu-11 in the cell-penetrating peptide Pep-1 with Lys. Pep-1-K showed strong antibacterial activity against reference strains (MIC = 1-2 μM) of Gram-positive and Gram-negative bacteria as well as against clinical isolates (MIC = 1-8 μM) of methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas aeruginosa. In contrast, Pep-1-K did not cause hemolysis of human erythrocytes even at 200 μM. These results indicate that Pep-1-K may be a good candidate for antimicrobial drug development, especially as a topical agent against antibiotic-resistant microorganisms. Tryptophan fluorescence studies indicated that the lack of hemolytic activity of Pep-1-K correlated with its weak ability to penetrate zwitterionic phosphatidylcholine/cholesterol (10:1, w/w) vesicles, which mimic eukaryotic membranes. Furthermore, Pep-1-K caused little or no dye leakage from negatively charged phosphatidylethanolamine/phosphatidylglycerol (7:3, w/w) vesicles, which mimic bacterial membranes but had a potent ability to cause depolarization of the cytoplasmic membrane potential of intact S. aureus cells. These results suggested that Pep-1-K kills microorganisms by not the membrane-disrupting mode but the formation of small channels that permit transit of ions or protons but not molecules as large as calcein

  11. Does Glucagon-like Peptide-1 Ameliorate Oxidative Stress in Diabetes?

    DEFF Research Database (Denmark)

    Petersen, Karen Ekkelund; Rakipovski, Günaj; Raun, Kirsten

    2016-01-01

    Glucagon-like peptide-1 (GLP-1) has shown to influence the oxidative stress status in a number of in vitro, in vivo and clinical studies. Well-known effects of GLP-1 including better glycemic control, decreased food intake, increased insulin release and increased insulin sensitivity may indirectly...... a controversial topic but could hold a therapeutic potential against micro- and macrovascular diabetic complications. This review discusses the presently available knowledge from experimental and clinical studies on the effects of GLP-1 on oxidative stress in diabetes and diabetes-related complications....

  12. Fbs1 protects the malfolded glycoproteins from the attack of peptide:N-glycanase

    International Nuclear Information System (INIS)

    Yamaguchi, Yoshiki; Hirao, Takeshi; Sakata, Eri; Kamiya, Yukiko; Kurimoto, Eiji; Yoshida, Yukiko; Suzuki, Tadashi; Tanaka, Keiji; Kato, Koichi

    2007-01-01

    Fbs1 is a cytosolic lectin putatively operating as a chaperone as well as a substrate-recognition subunit of the SCF Fbs1 ubiquitin ligase complex. To provide structural and functional basis of preferential binding of Fbs1 to unfolded glycoproteins, we herein characterize the interaction of Fbs1 with a heptapeptide carrying Man 3 GlcNAc 2 by nuclear magnetic resonance (NMR) spectroscopy and other biochemical methods. Inspection of the NMR data obtained by use of the isotopically labeled glycopeptide indicated that Fbs1 interacts with sugar-peptide junctions, which are shielded in native glycoprotein, in many cases, but become accessible to Fbs1 in unfolded glycoproteins. Furthermore, Fbs1 was shown to inhibit deglycosylation of denatured ribonuclease B by a cytosolic peptide:N-glycanase (PNGase). On the basis of these data, we suggest that Fbs1 captures malfolded glycoproteins, protecting them from the attack of PNGase, during the chaperoning or ubiquitinating operation in the cytosol

  13. Glucagon-Like Peptide-1 and Its Class B G Protein–Coupled Receptors: A Long March to Therapeutic Successes

    Science.gov (United States)

    de Graaf, Chris; Donnelly, Dan; Wootten, Denise; Lau, Jesper; Sexton, Patrick M.; Miller, Laurence J.; Ahn, Jung-Mo; Liao, Jiayu; Fletcher, Madeleine M.; Brown, Alastair J. H.; Zhou, Caihong; Deng, Jiejie; Wang, Ming-Wei

    2016-01-01

    The glucagon-like peptide (GLP)-1 receptor (GLP-1R) is a class B G protein–coupled receptor (GPCR) that mediates the action of GLP-1, a peptide hormone secreted from three major tissues in humans, enteroendocrine L cells in the distal intestine, α cells in the pancreas, and the central nervous system, which exerts important actions useful in the management of type 2 diabetes mellitus and obesity, including glucose homeostasis and regulation of gastric motility and food intake. Peptidic analogs of GLP-1 have been successfully developed with enhanced bioavailability and pharmacological activity. Physiologic and biochemical studies with truncated, chimeric, and mutated peptides and GLP-1R variants, together with ligand-bound crystal structures of the extracellular domain and the first three-dimensional structures of the 7-helical transmembrane domain of class B GPCRs, have provided the basis for a two-domain–binding mechanism of GLP-1 with its cognate receptor. Although efforts in discovering therapeutically viable nonpeptidic GLP-1R agonists have been hampered, small-molecule modulators offer complementary chemical tools to peptide analogs to investigate ligand-directed biased cellular signaling of GLP-1R. The integrated pharmacological and structural information of different GLP-1 analogs and homologous receptors give new insights into the molecular determinants of GLP-1R ligand selectivity and functional activity, thereby providing novel opportunities in the design and development of more efficacious agents to treat metabolic disorders. PMID:27630114

  14. Maternally derived anti-fibroblast growth factor 23 antibody as new tool to reduce phosphorus requirement of chicks.

    Science.gov (United States)

    Ren, Zhouzheng; Bütz, Daniel E; Sand, Jordan M; Cook, Mark E

    2017-04-01

    Novel means to reduce phosphate input into poultry feeds and increase its retention would preserve world phosphate reserves and reduce environmental impact of poultry production. Here we show that a maternally derived antibody to a fibroblast growth factor-23 (FGF-23) peptide (GMNPPPYS) alleviated phosphorus deficiency in chicks fed low non-phytate phosphorus (nPP) diets. White Leghorn laying hens were vaccinated with either an adjuvant control or the synthetic FGF-23 peptide, and chicks with control or anti-FGF-23 maternal antibodies were fed a diet containing either 0.13 or 0.45% nPP (experiment 1), and 0.20 or 0.45% nPP (experiment 2) for 14 d. In both experiments, decreasing nPP from 0.45 to 0.13 or 0.20% decreased BW gain, G:F, excreta phosphorus, plasma phosphate, and plasma FGF-23 at all time periods examined (nPP main effect, P posture scores (d 7, 14) and bone lesion scores (d 14) decreased and plasma phosphate (d 14) increased in anti-FGF-23 chicks fed 0.13% nPP, compared to those with control antibody on the same diet (P < 0.05). In experiment 2, chicks with maternal anti-FGF-23 antibody had increased tibiotarsi ash (d 14), and plasma phosphate (d 14) and 1,25(OH)2D3 (d 14) levels, compared to chicks with control antibody (antibody main effect, P < 0.05). BW gain and G:F were increased in chicks with anti-FGF-23 antibody fed 0.20% nPP, compared to control antibody chicks on the same diet, at all time periods examined (P < 0.05). In conclusion, maternally-derived anti-FGF-23 antibody increased phosphorus retention in chicks fed diets containing either 0.13 or 0.20% nPP and thereby, reduced signs of phosphorus deficiency. © 2016 Poultry Science Association Inc.

  15. Temperature dependence of looping rates in a short peptide.

    Science.gov (United States)

    Roccatano, Danilo; Sahoo, Harekrushna; Zacharias, Martin; Nau, Werner M

    2007-03-15

    Knowledge of the influence of chain length and amino acid sequence on the structural and dynamic properties of small peptides in solution provides essential information on protein folding pathways. The combination of time-resolved optical spectroscopy and molecular dynamics (MD) simulation methods has become a powerful tool to investigate the kinetics of end-to-end collisions (looping rates) in short peptides, which are relevant in early protein folding events. We applied the combination of both techniques to study temperature-dependent (280-340 K) looping rates of the Dbo-AlaGlyGln-Trp-NH2 peptide, where Dbo represents a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine, which served as a fluorescent probe in the time-resolved spectroscopic experiments. The experimental looping rates increased from 4.8 x 10(7) s(-1) at 283 K to 2.0 x 10(8) s(-1) at 338 K in H2O. The corresponding Arrhenius plot provided as activation parameters Ea = 21.5 +/- 1.0 kJ mol(-1) and ln(A/s-1) = 26.8 +/- 0.2 in H2O. The results in D2O were consistent with a slight solvent viscosity effect, i.e., the looping rates were 10-20% slower. MD simulations were performed with the GROMOS96 force field in a water solvent model, which required first a parametrization of the synthetic amino acid Dbo. After corrections for solvent viscosity effects, the calculated looping rates varied from 1.5 x 10(8) s(-1) at 280 K to 8.2 x 10(8) s(-1) at 340 K in H2O, which was about four times larger than the experimental data. The calculated activation parameters were Ea = 24.7 +/- 1.5 kJ mol(-1) and ln(A/s(-1)) = 29.4 +/- 0.1 in H2O.

  16. Phosphorylation-induced conformational changes in short peptides probed by fluorescence resonance energy transfer in the 10A domain.

    Science.gov (United States)

    Sahoo, Harekrushna; Nau, Werner M

    2007-03-26

    Phosphorylation-induced conformational changes in short polypeptides were probed by a fluorescence resonance energy transfer (FRET) method by employing a short-distance FRET pair (R(0) approximately 10 A) based on tryptophan as natural donor and a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) as synthetic acceptor. Two substrates for kinases, LeuArgArgTrpSerLeuGly-Dbo (peptide I) and TrpLysArgThrLeuArgArg-Dbo (peptide II), were investigated, with serine and threonine, respectively, as phosphorylation sites. Steady-state and time-resolved fluorescence experiments in H(2)O revealed a decrease in FRET efficiency for peptide I and an increase for peptide II; this suggested that the effective distances between donor and acceptor increased and decreased, respectively. The same trends and similar absolute variations in effective donor-acceptor distances were observed in propylene glycol, a less polar and highly viscous solvent; this suggested that the variations are due to intrinsic structural preferences. Fitting of the time-resolved decay traces according to a distribution function model (Gaussian distribution) provided the mean donor-acceptor distances, which showed an increase upon phosphorylation for peptide I (from 9.7 to 10.5 A) and a decrease for peptide II (from 10.9 to 9.3 A) in H(2)O. The broadness (half-width) of the distributions, which provides a measure of the rigidity of the peptides, remained similar upon phosphorylation of peptide I (3.0 versus 3.1 A), but decreased for peptide II (from 3.1 to 0.73 A in H(2)O); this suggests a more compact, structured conformation upon phosphorylation of the latter peptide. The elongation of the peptide backbone (by ca. 0.7 A) for peptide I is attributed to an increase in steric demand upon phosphorylation, which favors an extended conformation. The contraction (by ca. 1.4 A) and structural rigidification of peptide II is attributed to attractive Coulombic interactions and hydrogen bonding between the

  17. Secretion of glucagon-like peptide-1 in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Calanna, S; Christensen, M; Holst, Jens Juul

    2013-01-01

    We carried out a systematic review of clinical studies investigating glucagon-like peptide-1 (GLP-1) secretion in patients with type 2 diabetes and non-diabetic controls and performed meta-analyses of plasma total GLP-1 concentrations during an OGTT and/or meal test....

  18. Early and late HIV-1 membrane fusion events are impaired by sphinganine lipidated peptides that target the fusion site.

    Science.gov (United States)

    Klug, Yoel A; Ashkenazi, Avraham; Viard, Mathias; Porat, Ziv; Blumenthal, Robert; Shai, Yechiel

    2014-07-15

    Lipid-conjugated peptides have advanced the understanding of membrane protein functions and the roles of lipids in the membrane milieu. These lipopeptides modulate various biological systems such as viral fusion. A single function has been suggested for the lipid, binding to the membrane and thus elevating the local concentration of the peptide at the target site. In the present paper, we challenged this argument by exploring in-depth the antiviral mechanism of lipopeptides, which comprise sphinganine, the lipid backbone of DHSM (dihydrosphingomyelin), and an HIV-1 envelope-derived peptide. Surprisingly, we discovered a partnership between the lipid and the peptide that impaired early membrane fusion events by reducing CD4 receptor lateral diffusion and HIV-1 fusion peptide-mediated lipid mixing. Moreover, only the joint function of sphinganine and its conjugate peptide disrupted HIV-1 fusion protein assembly and folding at the later fusion steps. Via imaging techniques we revealed for the first time the direct localization of these lipopeptides to the virus-cell and cell-cell contact sites. Overall, the findings of the present study may suggest lipid-protein interactions in various biological systems and may help uncover a role for elevated DHSM in HIV-1 and its target cell membranes.

  19. Regulator of differentiation 1 (ROD1) binds to the amphipathic C-terminal peptide of thrombospondin-4 and is involved in its mitogenic activity.

    Science.gov (United States)

    Sadvakassova, Gulzhakhan; Dobocan, Monica C; Difalco, Marcos R; Congote, Luis F

    2009-09-01

    The matrix protein thrombospondin-4 has an acidic amphipathic C-terminal peptide (C21) which stimulates erythroid cell proliferation. Here we show that C21 stimulates red cell formation in anemic mice in vivo. In vitro experiments indicated that the peptide-mediated increase of erythroid colony formation in cultures of human CD34+ hematopoietic progenitor cells was possible only under continuous presence of erythropoietin. In the absence of this cytokine, C21 stimulated exclusively myeloid colony formation. Therefore, the peptide is not a specific erythroid differentiation factor. In fact, it is mitogenic in non-erythroid cells, such as skin fibroblasts and kidney epithelial cells. In erythroleukemic TF-1 cells, it actually decreased the production of the erythroid differentiation marker glycophorin A. C21-affinity chromatography revealed regulator of differentiation 1 (ROD1) as a major C21-binding protein. ROD1 is the hematopoietic cell paralog of polypyrimidine tract binding proteins (PTBs), RNA splice regulators which regulate differentiation by repressing tissue-specific exons. ROD1 binding to C21 was strongly inhibited by synthetic RNAs in the order poly A > poly U > poly G = poly C and was weakly inhibited by a synthetic phosphorylated peptide mimicking the C-terminal domain of RNA polymerase II. Cellular overexpression or knockdown experiments of ROD1 suggest a role for this protein in the mitogenic activity of C21. Since the nuclear proteins ROD1 and PTBs regulate differentiation at a posttranscriptional level and there is a fast nuclear uptake of C21, we put forward the idea that the peptide is internalized, goes to the nucleus and maintains cells in a proliferative state by supporting ROD1-mediated inhibition of differentiation.

  20. Immunohistochemical distribution of regulatory peptides in the human fetal adenohypophysis

    Science.gov (United States)

    Reyes, R; Valladares, F; Gutiérrez, R; González, M; Bello, A R

    2008-01-01

    We have studied here the cellular distribution of several regulatory peptides in hormone-producing cells of the human pituitary during the fetal period. Immunohistochemistry was used to show the expression of several regulatory peptides, namely Angiotensin-II, Neurotensin and Galanin, at successive gestational stages and their co-localization with hormones in the human fetal adenohypophysis. Somatotrophs, gonadotrophs and thyrotrophs were differentiated earliest. At gestational week 9, Angiotensin-II immunoreactivity was co-localized only with growth hormone immunoreactivity in somatotrophs, one of the first hormone-producing cells to differentiate. This co-localization remained until week 37. Neurotensin immunoreactivity was present in gonadotrophs and thyrotrophs in week 23, after FSH and TSH hormone differentiation. Galanin immunoreactivity was present in all hormone-producing cell types except corticotrophs. The different pro-opiomelanocortin-derived peptides were detected at different stages of gestation and adrenocorticotrophic hormone immunoreaction was the last to be detected. Our results show an interesting relationship between regulatory peptides and hormones during human fetal development, which could imply that these peptides play a regulatory role in the development of pituitary function. PMID:18510508

  1. Endogenous collagen peptide activation of CD1d-restricted NKT cells ameliorates tissue-specific inflammation in mice.

    Science.gov (United States)

    Liu, Yawei; Teige, Anna; Mondoc, Emma; Ibrahim, Saleh; Holmdahl, Rikard; Issazadeh-Navikas, Shohreh

    2011-01-01

    NKT cells in the mouse recognize antigen in the context of the MHC class I-like molecule CD1d and play an important role in peripheral tolerance and protection against autoimmune and other diseases. NKT cells are usually activated by CD1d-presented lipid antigens. However, peptide recognition in the context of CD1 has also been documented, although no self-peptide ligands have been reported to date. Here, we have identified an endogenous peptide that is presented by CD1d to activate mouse NKT cells. This peptide, the immunodominant epitope from mouse collagen type II (mCII707-721), was not associated with either MHC class I or II. Activation of CD1d-restricted mCII707-721-specific NKT cells was induced via TCR signaling and classical costimulation. In addition, mCII707-721-specific NKT cells induced T cell death through Fas/FasL, in an IL-17A-independent fashion. Moreover, mCII707-721-specific NKT cells suppressed a range of in vivo inflammatory conditions, including delayed-type hypersensitivity, antigen-induced airway inflammation, collagen-induced arthritis, and EAE, which were all ameliorated by mCII707-721 vaccination. The findings presented here offer new insight into the intrinsic roles of NKT cells in health and disease. Given the results, endogenous collagen peptide activators of NKT cells may offer promise as novel therapeutics in tissue-specific autoimmune and inflammatory diseases.

  2. Superior Antifouling Performance of a Zwitterionic Peptide Compared to an Amphiphilic, Non-Ionic Peptide.

    Science.gov (United States)

    Ye, Huijun; Wang, Libing; Huang, Renliang; Su, Rongxin; Liu, Boshi; Qi, Wei; He, Zhimin

    2015-10-14

    The aim of this study was to explore the influence of amphiphilic and zwitterionic structures on the resistance of protein adsorption to peptide self-assembled monolayers (SAMs) and gain insight into the associated antifouling mechanism. Two kinds of cysteine-terminated heptapeptides were studied. One peptide had alternating hydrophobic and hydrophilic residues with an amphiphilic sequence of CYSYSYS. The other peptide (CRERERE) was zwitterionic. Both peptides were covalently attached onto gold substrates via gold-thiol bond formation. Surface plasmon resonance analysis results showed that both peptide SAMs had ultralow or low protein adsorption amounts of 1.97-11.78 ng/cm2 in the presence of single proteins. The zwitterionic peptide showed relatively higher antifouling ability with single proteins and natural complex protein media. We performed molecular dynamics simulations to understand their respective antifouling behaviors. The results indicated that strong surface hydration of peptide SAMs contributes to fouling resistance by impeding interactions with proteins. Compared to the CYSYSYS peptide, more water molecules were predicted to form hydrogen-bonding interactions with the zwitterionic CRERERE peptide, which is in agreement with the antifouling test results. These findings reveal a clear relation between peptide structures and resistance to protein adsorption, facilitating the development of novel peptide-containing antifouling materials.

  3. 23 CFR 1.33 - Conflicts of interest.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Conflicts of interest. 1.33 Section 1.33 Highways... § 1.33 Conflicts of interest. No official or employee of a State or any other governmental... project shall have, directly or indirectly, any financial or other personal interest in any such contract...

  4. Correlation of adjusted blood requirement index with treatment intervention and outcome in patients presenting with acute variceal bleeding

    International Nuclear Information System (INIS)

    Zaberi, B.F.; Riaz, M.F.; Sultan, B.A.; Gobindram, P.

    2007-01-01

    To determine the correlation of ABRI with treatment intervention and outcome as discharged or expired in patients of acute variceal bleed. Records of all the patients admitted in Medical Unit-IV, Civil Hospital Karachi with acute variceal bleeding during January 2004 to October 2006 were retrieved. Use of vasoactive agents (Terlipressin/Octreotide), endoscopic band ligation (EBL) and outcome (Discharged/Expired) were noted. ABRI was calculated by the following formula. ABRI= Blood Units Transfused/((Final Hematocrit-Initial Hematocrit)+0.01) Mean ABRI were compared by student's 't' test according to vasoactive therapy, EBL and outcome. Correlation of ABRI with the same variables was also studied by plotting Receiver Operative Curves (ROC). Seventy six patients fulfilling inclusion criteria were selected. No statistically significant difference was observed in the mean ABRI scores when compared according to vasoactive drug administration, EBL and outcome. Significant correlation with mortality was seen on ROC plot with significantly larger area under the curve. (author)

  5. Novel anti-oxidative peptides from enzymatic digestion of human milk

    DEFF Research Database (Denmark)

    Tsopmo, Apollinaire; Romanowski, Andrea; Banda, Lyness

    2011-01-01

    Humanmilk pepsin and pancreatin digests were separated using molecular membrane and reverse phase chromatography. Chemical screening of the resulting fractions using the ORAC antioxidant assay yielded a peptide fraction (PF-23) with high antioxidant activity (5207 μM Trolox Equivalents (TE...

  6. Glucagon-like peptide-1 is specifically involved in sweet taste transmission.

    Science.gov (United States)

    Takai, Shingo; Yasumatsu, Keiko; Inoue, Mayuko; Iwata, Shusuke; Yoshida, Ryusuke; Shigemura, Noriatsu; Yanagawa, Yuchio; Drucker, Daniel J; Margolskee, Robert F; Ninomiya, Yuzo

    2015-06-01

    Five fundamental taste qualities (sweet, bitter, salty, sour, umami) are sensed by dedicated taste cells (TCs) that relay quality information to gustatory nerve fibers. In peripheral taste signaling pathways, ATP has been identified as a functional neurotransmitter, but it remains to be determined how specificity of different taste qualities is maintained across synapses. Recent studies demonstrated that some gut peptides are released from taste buds by prolonged application of particular taste stimuli, suggesting their potential involvement in taste information coding. In this study, we focused on the function of glucagon-like peptide-1 (GLP-1) in initial responses to taste stimulation. GLP-1 receptor (GLP-1R) null mice had reduced neural and behavioral responses specifically to sweet compounds compared to wild-type (WT) mice. Some sweet responsive TCs expressed GLP-1 and its receptors were expressed in gustatory neurons. GLP-1 was released immediately from taste bud cells in response to sweet compounds but not to other taste stimuli. Intravenous administration of GLP-1 elicited transient responses in a subset of sweet-sensitive gustatory nerve fibers but did not affect other types of fibers, and this response was suppressed by pre-administration of the GLP-1R antagonist Exendin-4(3-39). Thus GLP-1 may be involved in normal sweet taste signal transmission in mice. © FASEB.

  7. N-Formylated humanin activates both formyl peptide receptor-like 1 and 2

    International Nuclear Information System (INIS)

    Harada, Masataka; Habata, Yugo; Hosoya, Masaki; Nishi, Kazunori; Fujii, Ryo; Kobayashi, Makoto; Hinuma, Shuji

    2004-01-01

    We have discovered that humanin (HN) acts as a ligand for formyl peptide receptor-like 1 (FPRL1) and 2 (FPRL2). This discovery was based on our finding that HN suppressed forskolin-induced cAMP production in Chinese hamster ovary (CHO) cells expressing human FPRL1 (CHO-hFPRL1) or human FPRL2 (CHO-hFPRL2). In addition, we found that N-formylated HN (fHN) performed more potently as a ligand for FPRL1 than HN: in CHO-hFPRL1 cells, the effective concentration for the half-maximal response (EC 50 ) value of HN was 3.5 nM, while that of fHN was 0.012 nM. We demonstrated by binding experiments using [ 125 I]-W peptide that HN and fHN directly interacted with hFPRL1 on the membrane. In addition, we found that HN and fHN showed strong chemotactic activity for CHO-hFPRL1 and CHO-hFPRL2 cells. HN is known to have a protective effect against neuronal cell death. Our findings contribute to the understanding of the mechanism behind HN's function

  8. Galectin-1-asialofetuin interaction is inhibited by peptides containing the tyr-xxx-tyr motif acting on the glycoprotein.

    Science.gov (United States)

    Wéber, Edit; Hetényi, Anasztázia; Váczi, Balázs; Szolnoki, Eva; Fajka-Boja, Roberta; Tubak, Vilmos; Monostori, Eva; Martinek, Tamás A

    2010-01-25

    Galectin-1 (Gal-1), a ubiquitous beta-galactoside-binding protein expressed by various normal and pathological tissues, has been implicated in cancer and autoimmune/inflammatory diseases in consequence of its regulatory role in adhesion, cell viability, proliferation, and angiogenesis. The functions of Gal-1 depend on its affinity for beta-galactoside-containing glycoconjugates; accordingly, the inhibition of sugar binding blocks its functions, hence promising potential therapeutic tools. The Tyr-Xxx-Tyr peptide motifs have been reported to be glycomimetic sequences, mainly on the basis of their inhibitory effect on the Gal-1-asialofetuin (ASF) interaction. However, the results regarding the efficacy of the Tyr-Xxx-Tyr motif as a glycomimetic inhibitor are still controversial. The present STD and trNOE NMR experiments reveal that the Tyr-Xxx-Tyr peptides studied do not bind to Gal-1, whereas their binding to ASF is clearly detected. (15)N,(1)H HSQC titrations with (15)N-labeled Gal-1 confirm the absence of any peptide-Gal-1 interaction. These data indicate that the Tyr-Xxx-Tyr peptides tested in this work are not glycomimetics as they interact with ASF via an unrevealed molecular linkage.

  9. Sequence of the radioactive tryptic peptide obtained after inactivating the F1-ATPase of the thermophilic bacterium PS3 with 5'-p-fluorosulfonylbenzoyl[3H]adenosine at 65 degrees C

    International Nuclear Information System (INIS)

    Bullough, D.A.; Yoshida, M.; Allison, W.S.

    1986-01-01

    Following a lag of about 30 min, the F1-ATPase from the thermophilic bacterium, PS3 (TF1), was inactivated slowly by 0.8 mM 5'-p-fluorosulfonylbenzoyladenosine (FSBA) at 23 degrees C and pH 7.0. When the enzyme was treated with 0.2 mM FSBA at pH 7.0 and 23 degrees C for 15 min and gel-filtered, no enzyme activity was lost. However, the lag in inactivation was abolished when the enzyme was subsequently incubated with 2.0 mM FSBA at 23 degrees C in the pH range from 6.8 to 10.0. The pH-inactivation profile obtained under these conditions revealed a pK alpha of about 9.3 which was associated with the inactivation. When pretreated TF1 was inactivated at 23 degrees C with [3H]FSBA by about 90%, greater than 20 mol of [3H]SBA was incorporated per mole of enzyme. TF1 was inactivated rapidly by 0.8 mM FSBA at pH 6.4 and 65 degrees C, and no lag was observed. Following inactivation of TF1 with 0.8 mM [3H]FSBA at 65 degrees C and pH 6.4, about 10 mol of [3H]SBA was incorporated per mole of enzyme. When a tryptic digest of the labeled enzyme was fractionated by reversed-phase high-performance liquid chromatography, a single major radioactive peptide was isolated. When subjected to automatic Edman degradation, this peptide was shown to have the amino acid sequence: A-L-A-P-E-I-V-G-E-E-H-X-Q-V-A-R, where X indicates that a phenylthiohydantoin derivative was not detected in cycle 12. However, from the DNA sequence of the gene encoding the subunit of TF1 (Y. Kagawa, M. Ishizuka, T. Saishu, and S. Nakao (1985)), this position has been shown to be occupied by tyrosine. This tyrosine is homologous with beta-Tyr-368 of the bovine mitochondrial F1-ATPase (MF1) the modification of which is responsible for the inactivation MF1 by FSBA

  10. Kinetic and structural characterization of amyloid-β peptide hydrolysis by human angiotensin-1-converting enzyme.

    Science.gov (United States)

    Larmuth, Kate M; Masuyer, Geoffrey; Douglas, Ross G; Schwager, Sylva L; Acharya, K Ravi; Sturrock, Edward D

    2016-03-01

    Angiotensin-1-converting enzyme (ACE), a zinc metallopeptidase, consists of two homologous catalytic domains (N and C) with different substrate specificities. Here we report kinetic parameters of five different forms of human ACE with various amyloid beta (Aβ) substrates together with high resolution crystal structures of the N-domain in complex with Aβ fragments. For the physiological Aβ(1-16) peptide, a novel ACE cleavage site was found at His14-Gln15. Furthermore, Aβ(1-16) was preferentially cleaved by the individual N-domain; however, the presence of an inactive C-domain in full-length somatic ACE (sACE) greatly reduced enzyme activity and affected apparent selectivity. Two fluorogenic substrates, Aβ(4-10)Q and Aβ(4-10)Y, underwent endoproteolytic cleavage at the Asp7-Ser8 bond with all ACE constructs showing greater catalytic efficiency for Aβ(4-10)Y. Surprisingly, in contrast to Aβ(1-16) and Aβ(4-10)Q, sACE showed positive domain cooperativity and the double C-domain (CC-sACE) construct no cooperativity towards Aβ(4-10)Y. The structures of the Aβ peptide-ACE complexes revealed a common mode of peptide binding for both domains which principally targets the C-terminal P2' position to the S2' pocket and recognizes the main chain of the P1' peptide. It is likely that N-domain selectivity for the amyloid peptide is conferred through the N-domain specific S2' residue Thr358. Additionally, the N-domain can accommodate larger substrates through movement of the N-terminal helices, as suggested by the disorder of the hinge region in the crystal structures. Our findings are important for the design of domain selective inhibitors as the differences in domain selectivity are more pronounced with the truncated domains compared to the more physiological full-length forms. The atomic coordinates and structure factors for N-domain ACE with Aβ peptides 4-10 (5AM8), 10-16 (5AM9), 1-16 (5AMA), 35-42 (5AMB) and (4-10)Y (5AMC) complexes have been deposited in the

  11. Non-invasive glucagon-like peptide-1 receptor imaging in pancreas with (18)F-Al labeled Cys(39)-exendin-4.

    Science.gov (United States)

    Mi, Baoming; Xu, Yuping; Pan, Donghui; Wang, Lizhen; Yang, Runlin; Yu, Chunjing; Wan, Weixing; Wu, Yiwei; Yang, Min

    2016-02-26

    Glucagon-like peptide-1 receptor (GLP-1R) is abundantly expressed on beta cells and may be an ideal target for the pancreas imaging. Monitoring the GLP-1R of pancreas could be benefit for understanding the pathophysiology of diabetes. In the present study, (18)F-Al labeled exendin-4 analog, (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, was evaluated for PET imaging GLP-1R in the pancreas. The targeting of (18)F-Al labeled exendin-4 analog was examined in healthy and streptozotocin induced diabetic rats. Rats were injected with (18)F-Al-NOTA-MAL-Cys(39)-exendin-4 and microPET imaging was performed at 1 h postinjection, followed by ex vivo biodistribution. GLP-1R expression in pancreas was determined through post mortern examinations. The pancreas of healthy rats was readily visualized after administration of (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, whereas the pancreas of diabetic rats, as well as those from rats co-injected with excess of unlabeled peptides, was barely visible by microPET. At 60 min postinjection, the pancreatic uptakes were 1.02 ± 0.15%ID/g and 0.23 ± 0.05%ID/g in healthy and diabetic rats respectively. Under block, the pancreatic uptakes of non-diabetic rats reduced to 0.21 ± 0.07%ID/g at the same time point. Biodistribution data and IHC staining confirmed the findings of the microPET imaging. The favorable preclinical data indicated that (18)F-Al-NOTA-MAL-Cys(39)-exendin-4may be suitable for non-invasive monitoring functional pancreatic beta cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Dynamics of lipid layers with/without bounded antimicrobial peptide halictine-1

    Czech Academy of Sciences Publication Activity Database

    Tesař, A.; Kopecký, V. Jr.; Kočišová, E.; Bednárová, Lucie

    2017-01-01

    Roč. 93, Nov (2017), s. 42-51 ISSN 0924-2031 R&D Projects: GA ČR GAP208/10/0376 Institutional support: RVO:61388963 Keywords : antibacterial peptide * halictine * liposome * phospholipid bilayer * infrared spectroscopy * attenuated total reflection Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 1.740, year: 2016

  13. Glucagon like peptide-1-induced glucose metabolism in differentiated human muscle satellite cells is attenuated by hyperglycemia

    DEFF Research Database (Denmark)

    Green, Charlotte J; Henriksen, Tora I; Pedersen, Bente K

    2012-01-01

    Glucagon like peptide-1 (GLP-1) stimulates insulin secretion from the pancreas but also has extra-pancreatic effects. GLP-1 may stimulate glucose uptake in cultured muscle cells but the mechanism is not clearly defined. Furthermore, while the pancreatic effects of GLP-1 are glucose-dependent, the......Glucagon like peptide-1 (GLP-1) stimulates insulin secretion from the pancreas but also has extra-pancreatic effects. GLP-1 may stimulate glucose uptake in cultured muscle cells but the mechanism is not clearly defined. Furthermore, while the pancreatic effects of GLP-1 are glucose...

  14. Enhanced glucagon-like peptide-1 (GLP-1) response to oral glucose in glucose-intolerant HIV-infected patients on antiretroviral therapy

    DEFF Research Database (Denmark)

    Andersen, O; Haugaard, S B; Holst, Jens Juul

    2005-01-01

    concentrations of GLP-1 and GIP were determined frequently during a 3-h, 75-g glucose tolerance test. Insulin secretion rates (ISRs) were calculated by deconvolution of C-peptide concentrations. RESULTS: The incremental area under the curve (incrAUC) for GLP-1 was increased by 250% in IGT patients compared...... without adjustment (r=0.38, Pglucose incrAUC (r=0.49, Pglucose-intolerant, HIV-infected male patients may display enhanced GLP-1 responses to oral glucose compared with normal glucose-tolerant HIV-infected male patients......OBJECTIVES: We investigated whether the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which are major regulators of glucose tolerance through the stimulation of insulin secretion, contribute to impaired glucose tolerance (IGT) among HIV...

  15. Potent peptidic fusion inhibitors of influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Rameshwar U.; Juraszek, Jarek; Brandenburg, Boerries; Buyck, Christophe; Schepens, Wim B. G.; Kesteleyn, Bart; Stoops, Bart; Vreeken, Rob J.; Vermond, Jan; Goutier, Wouter; Tang, Chan; Vogels, Ronald; Friesen, Robert H. E.; Goudsmit, Jaap; van Dongen, Maria J. P.; Wilson, Ian A.

    2017-09-28

    Influenza therapeutics with new targets and mechanisms of action are urgently needed to combat potential pandemics, emerging viruses, and constantly mutating strains in circulation. We report here on the design and structural characterization of potent peptidic inhibitors of influenza hemagglutinin. The peptide design was based on complementarity-determining region loops of human broadly neutralizing antibodies against the hemagglutinin (FI6v3 and CR9114). The optimized peptides exhibit nanomolar affinity and neutralization against influenza A group 1 viruses, including the 2009 H1N1 pandemic and avian H5N1 strains. The peptide inhibitors bind to the highly conserved stem epitope and block the low pH–induced conformational rearrangements associated with membrane fusion. These peptidic compounds and their advantageous biological properties should accelerate the development of new small molecule– and peptide-based therapeutics against influenza virus.

  16. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  17. Plasma levels of glucagon like peptide-1 associate with diastolic function in elderly men

    DEFF Research Database (Denmark)

    Nathanson, D; Zethelius, B; Berne, C

    2011-01-01

    Congestive heart failure is a major cause of morbidity and mortality in diabetes. Besides the glycaemic effects of glucagon-like peptide 1 (GLP-1) mimetics, their effects on the heart are of interest....

  18. Biotechnological Fluorescent Ligands of the Bradykinin B1 Receptor: Protein Ligands for a Peptide Receptor.

    Directory of Open Access Journals (Sweden)

    Xavier Charest-Morin

    Full Text Available The bradykinin (BK B1 receptor (B1R is a peculiar G protein coupled receptor that is strongly regulated to the point of being inducible in immunopathology. Limited clinical evidence suggests that its expression in peripheral blood mononuclear cells is a biomarker of active inflammatory states. In an effort to develop a novel imaging/diagnostic tool, we report the rational design and testing of a fusion protein that is a ligand of the human B1R but not likely to label peptidases. This ligand is composed of a fluorescent protein (FP (enhanced green FP [EGFP] or mCherry prolonged at its N-terminus by a spacer peptide and a classical peptide agonist or antagonist (des-Arg9-BK, [Leu8]des-Arg9-BK, respectively. The design of the spacer-ligand joint peptide was validated by a competition assay for [3H]Lys-des-Arg9-BK binding to the human B1R applied to 4 synthetic peptides of 18 or 19 residues. The labeling of B1R-expressing cells with EGFP or mCherry fused with 7 of such peptides was performed in parallel (microscopy. Both assays indicated that the best design was FP-(Asn-Glyn-Lys-des-Arg9-BK; n = 15 was superior to n = 5, suggesting benefits from minimizing steric hindrance between the FP and the receptor. Cell labeling concerned mostly plasma membranes and was inhibited by a B1R antagonist. EGFP-(Asn-Gly15-Lys-des-Arg9-BK competed for the binding of [3H]Lys-des-Arg9-BK to human recombinant B1R, being only 10-fold less potent than the unlabeled form of Lys-des-Arg9-BK to do so. The fusion protein did not label HEK 293a cells expressing recombinant human BK B2 receptors or angiotensin converting enzyme. This study identifies a modular C-terminal sequence that can be adapted to protein cargoes, conferring high affinity for the BK B1R, with possible applications in diagnostic cytofluorometry, histology and drug delivery (e.g., in oncology.

  19. D-Amino acids incorporation in the frog skin-derived peptide esculentin-1a(1-21)NH2 is beneficial for its multiple functions.

    Science.gov (United States)

    Di Grazia, Antonio; Cappiello, Floriana; Cohen, Hadar; Casciaro, Bruno; Luca, Vincenzo; Pini, Alessandro; Di, Y Peter; Shai, Yechiel; Mangoni, Maria Luisa

    2015-12-01

    Naturally occurring antimicrobial peptides (AMPs) represent promising future antibiotics. We have previously isolated esculentin-1a(1-21)NH2, a short peptide derived from the frog skin AMP esculentin-1a, with a potent anti-Pseudomonal activity. Here, we investigated additional functions of the peptide and properties responsible for these activities. For that purpose, we synthesized the peptide, as well as its structurally altered analog containing two D-amino acids. The peptides were then biophysically and biologically investigated for their cytotoxicity and immunomodulating activities. The data revealed that compared to the wild-type, the diastereomer: (1) is significantly less toxic towards mammalian cells, in agreement with its lower α-helical structure, as determined by circular dichroism spectroscopy; (2) is more effective against the biofilm form of Pseudomonas aeruginosa (responsible for lung infections in cystic fibrosis sufferers), while maintaining a high activity against the free-living form of this important pathogen; (3) is more stable in serum; (4) has a higher activity in promoting migration of lung epithelial cells, and presumably in healing damaged lung tissue, and (5) disaggregates and detoxifies the bacterial lipopolysaccharide (LPS), albeit less than the wild-type. Light scattering studies revealed a correlation between anti-LPS activity and the ability to disaggregate the LPS. Besides shedding light on the multifunction properties of esculentin-1a(1-21)NH2, the D-amino acid containing isomer may serve as an attractive template for the development of new anti-Pseudomonal compounds with additional beneficial properties. Furthermore, together with other studies, incorporation of D-amino acids may serve as a general approach to optimize the future design of new AMPs.

  20. Radiolabelled peptides for oncological diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Laverman, Peter; Boerman, Otto C.; Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Sosabowski, Jane K. [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom)

    2012-02-15

    Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The {sup 111}In-labelled somatostatin analogue octreotide (OctreoScan trademark) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours. (orig.)

  1. Reversible pH-controlled DNA-binding peptide nanotweezers: An in-silico study

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2008-11-01

    Full Text Available Gaurav Sharma1, Kaushal Rege2,3, David E Budil4, Martin L Yarmush2,5, Constantinos Mavroidis11Department of Mechanical and Industrial Engineering; 4Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA; 2The Center for Engineering in Medicine (CEM, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; 3Department of Chemical Engineering, Arizona State University, Tempe, AZ, USA; 5Department of Biomedical Engineering, Rutgers University, NJ, USAAbstract: We describe the molecular dynamics (MD-aided engineering design of mutant peptides based on the α-helical coiled-coil GCN4 leucine zipper peptide (GCN4-p1 in order to obtain environmentally-responsive nanotweezers. The actuation mechanism of the nanotweezers depends on the modification of electrostatic charges on the residues along the length of the coiled coil. Modulating the solution pH between neutral and acidic values results in the reversible movement of helices toward and away from each other and creates a complete closed-open-closed transition cycle between the helices. Our results indicate that the mutants show a reversible opening of up to 15 Å (1.5 nm; approximately 150% of the initial separation upon pH actuation. Investigation on the physicochemical phenomena that influence conformational properties, structural stability, and reversibility of the coiled-coil peptide-based nanotweezers revealed that a rationale- and design-based approach is needed to engineer stable peptide or macromolecules into stimuli-responsive devices. The efficacy of the mutant that demonstrated the most significant reversible actuation for environmentally responsive modulation of DNA-binding activity was also demonstrated. Our results have significant implications in bioseparations and in the engineering of novel transcription factors.Keywords: bionanotechnology, nanotweezers, coiled-coil, GCN4, leucine zipper, molecular dynamics, environmentally

  2. Radiopharmaceutical development of radiolabelled peptides

    Energy Technology Data Exchange (ETDEWEB)

    Fani, Melpomeni; Maecke, Helmut R. [University Hospital Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

    2012-02-15

    Receptor targeting with radiolabelled peptides has become very important in nuclear medicine and oncology in the past few years. The overexpression of many peptide receptors in numerous cancers, compared to their relatively low density in physiological organs, represents the molecular basis for in vivo imaging and targeted radionuclide therapy with radiolabelled peptide-based probes. The prototypes are analogs of somatostatin which are routinely used in the clinic. More recent developments include somatostatin analogs with a broader receptor subtype profile or with antagonistic properties. Many other peptide families such as bombesin, cholecystokinin/gastrin, glucagon-like peptide-1 (GLP-1)/exendin, arginine-glycine-aspartic acid (RGD) etc. have been explored during the last few years and quite a number of potential radiolabelled probes have been derived from them. On the other hand, a variety of strategies and optimized protocols for efficient labelling of peptides with clinically relevant radionuclides such as {sup 99m}Tc, M{sup 3+} radiometals ({sup 111}In, {sup 86/90}Y, {sup 177}Lu, {sup 67/68}Ga), {sup 64/67}Cu, {sup 18}F or radioisotopes of iodine have been developed. The labelling approaches include direct labelling, the use of bifunctional chelators or prosthetic groups. The choice of the labelling approach is driven by the nature and the chemical properties of the radionuclide. Additionally, chemical strategies, including modification of the amino acid sequence and introduction of linkers/spacers with different characteristics, have been explored for the improvement of the overall performance of the radiopeptides, e.g. metabolic stability and pharmacokinetics. Herein, we discuss the development of peptides as radiopharmaceuticals starting from the choice of the labelling method and the conditions to the design and optimization of the peptide probe, as well as some recent developments, focusing on a selected list of peptide families, including somatostatin

  3. Reversal of obesity and insulin resistance by a non-peptidic glucagon-like peptide-1 receptor agonist in diet-induced obese mice.

    Directory of Open Access Journals (Sweden)

    Min He

    Full Text Available BACKGROUND: Glucagon-like peptide-1 (GLP-1 is recognized as an important regulator of glucose homeostasis. Efforts to utilize GLP-1 mimetics in the treatment of diabetes have yielded clinical benefits. A major hurdle for an effective oral therapy has been the difficulty of finding a non-peptidic GLP-1 receptor (GLP-1R agonist. While its oral bioavailability still poses significant challenges, Boc5, one of the first such compounds, has demonstrated the attainment of GLP-1R agonism in diabetic mice. The present work was to investigate whether subchronic Boc5 treatment can restore glycemic control and induce sustainable weight loss in diet-induced obese (DIO mice, an animal model of human obesity and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: DIO mice were treated three times a week with Boc5 (0.3, 1 and 3 mg for 12 weeks. Body weight, body mass index (BMI, food intake, fasting glucose, intraperitoneal glucose tolerance and insulin induced glucose clearance were monitored regularly throughout the treatment. Glucose-stimulated insulin secretion, β-cell mass, islet size, body composition, serum metabolic profiles, lipogenesis, lipolysis, adipose hypertrophy and lipid deposition in the liver and muscle were also measured after 12 weeks of dosing. Boc5 dose-dependently reduced body weight, BMI and food intake in DIO mice. These changes were associated with significant decreases in fat mass, adipocyte hypertrophy and peripheral tissue lipid accumulation. Boc5 treatment also restored glycemic control through marked improvement of insulin sensitivity and normalization of β-cell mass. Administration of Boc5 (3 mg reduced basal but enhanced insulin-mediated glucose incorporation and noradrenaline-stimulated lipolysis in isolated adipocytes from obese mice. Furthermore, circulating leptin, adiponectin, triglyceride, total cholesterol, nonesterified fatty acid and high-density lipoprotein/low-density lipoprotein ratio were normalized to various

  4. Glucagon-like peptide-1, a new hormone of the entero-insular axis

    DEFF Research Database (Denmark)

    Orskov, C

    1992-01-01

    reported in Type 2 (noninsulin-dependent) diabetic patients, however, the consequences of the elevation are not yet known. However, elevated levels of glucagon-like peptide-1 in patients with increased gastric emptying rate (post-gastrectomy syndromes) may be responsible for the exaggerated insulin...

  5. Z-contrast imaging of ordered structures in Pb(Mg1/3Nb2/3)O3 and Ba(Mg1/3Nb2/3)O3

    International Nuclear Information System (INIS)

    Yan, Y.; Pennycook, S.J.; Xu, Z.; Viehland, D.

    1998-02-01

    Lead-based cubic perovskites such as Pb(B 1/3 2+ B 2/3 5+ )O 3 (B 2+ Mg, Co, Ni, Zn; B 5+ = Nb, Ta) are relaxor ferroelectrics. Localized order and disorder often occur in materials of this type. In the Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) family, previous studies have proposed two models, space-charge and charge-balance models. In the first model, the ordered regions carry a net negative charge [Pb(Mg 1/2 Nb 1/2 )O 3 ], while in the second model it does not carry a net charge [Pb((Mg 2/3 Nb 1/3 ) 1/2 Nb 1/2 )O 3 ]. However, no direct evidence for these two models has appeared in the literature yet. In this paper the authors report the first direct observations of local ordering in undoped and La-doped Pb(Mg 1/3 Nb 2/3 )O 3 , using high-resolution Z-contrast imaging. Because the ordered structure in Ba(Mg 1/3 Nb 2/3 )O 3 is well known, the Z-contrast image from an ordered domain is used as a reference for this study

  6. Design and synthesis of a new peptide derived from Fasciola gigantica cathepsin L1 with potential application in serodiagnosis of fascioliasis.

    Science.gov (United States)

    Meshgi, Behnam; Jalousian, Fatemeh; Fathi, Saeid; Jahani, Zahra

    2018-06-01

    Fascioliasis is a global parasitic disease that affects domestic animals and causes considerable economic losses in the process of domestic animal breeding in endemic regions. The cause of the disease involves a liver trematode of the genus Fasciola, which secretes materials into a host's body (mainly proteins) in order to protect it from the host's immune system. These materials can be involved in the migration, growth, and nutrition of the parasite. Among the expressive proteins of Fasciola, proteases have been introduced as the appropriate targets for diagnosis, treatment, and vaccination against parasites. Cathepsin L (CL) is a member of cysteine proteases; it is widely expressed in the Fasciola species. The aim of this study was to evaluate two synthetic peptides from F. gigantica CL1 for improving serological diagnosis of the Fasciola infection. Therefore, the potential diagnostic value of the surface epitopes of CL1 was assessed using ELISA. In the current study, bioinformatics tools were applied to select two appropriate epitopes of Fasciola Cathepsin L1 as synthetic antigens. Their diagnostic values were evaluated by two methods of indirect ELISA and dot blot analysis. The findings revealed that the first peptide at a dilution ratio of 1:400 and the second peptide at a dilution ratio of 1:100 had the best results and the best concentration of antigens was introduced at 4 μg/ml. Moreover, 191 sera samples were analyzed by both peptides by using the ELISA method, including fascioliasis sera, other parasitic sera and negative sera. The sensitivity of the peptides 1-ELISA and peptide 2-ELISA for the diagnosis of the various cases was 100%. The specificity of the first peptide was 87.3% and its efficacy was determined to be 93.65%. The specificity and the efficacy of the second peptide were 79% and 89.5%, respectively. The positive predictive values of the first and second peptides were obtained to be 86.27% and 79.27% respectively, and the negative

  7. Improved methods for predicting peptide binding affinity to MHC class II molecules

    DEFF Research Database (Denmark)

    Jensen, Kamilla Kjærgaard; Andreatta, Massimo; Marcatili, Paolo

    2018-01-01

    Major histocompatibility complex class II (MHC-II) molecules are expressed on the surface of professional antigen presenting cells where they display peptides to T helper cells, which orchestrate the onset and outcome of many host immune responses. Understanding which peptides will be presented b...... are publicly available at www.cbs.dtu.dk/services/NetMHCII-2.3 and www.cbs.dtu.dk/services/NetMHCIIpan-3.2. This article is protected by copyright. All rights reserved....

  8. Pharmacological characterization of potent and selective NaV1.7 inhibitors engineered from Chilobrachys jingzhao tarantula venom peptide JzTx-V.

    Directory of Open Access Journals (Sweden)

    Bryan D Moyer

    Full Text Available Identification of voltage-gated sodium channel NaV1.7 inhibitors for chronic pain therapeutic development is an area of vigorous pursuit. In an effort to identify more potent leads compared to our previously reported GpTx-1 peptide series, electrophysiology screening of fractionated tarantula venom discovered the NaV1.7 inhibitory peptide JzTx-V from the Chinese earth tiger tarantula Chilobrachys jingzhao. The parent peptide displayed nominal selectivity over the skeletal muscle NaV1.4 channel. Attribute-based positional scan analoging identified a key Ile28Glu mutation that improved NaV1.4 selectivity over 100-fold, and further optimization yielded the potent and selective peptide leads AM-8145 and AM-0422. NMR analyses revealed that the Ile28Glu substitution changed peptide conformation, pointing to a structural rationale for the selectivity gains. AM-8145 and AM-0422 as well as GpTx-1 and HwTx-IV competed for ProTx-II binding in HEK293 cells expressing human NaV1.7, suggesting that these NaV1.7 inhibitory peptides interact with a similar binding site. AM-8145 potently blocked native tetrodotoxin-sensitive (TTX-S channels in mouse dorsal root ganglia (DRG neurons, exhibited 30- to 120-fold selectivity over other human TTX-S channels and exhibited over 1,000-fold selectivity over other human tetrodotoxin-resistant (TTX-R channels. Leveraging NaV1.7-NaV1.5 chimeras containing various voltage-sensor and pore regions, AM-8145 mapped to the second voltage-sensor domain of NaV1.7. AM-0422, but not the inactive peptide analog AM-8374, dose-dependently blocked capsaicin-induced DRG neuron action potential firing using a multi-electrode array readout and mechanically-induced C-fiber spiking in a saphenous skin-nerve preparation. Collectively, AM-8145 and AM-0422 represent potent, new engineered NaV1.7 inhibitory peptides derived from the JzTx-V scaffold with improved NaV selectivity and biological activity in blocking action potential firing in both

  9. The common equine class I molecule Eqca-1*00101 (ELA-A3.1) is characterized by narrow peptide binding and T cell epitope repertoires.

    Science.gov (United States)

    Bergmann, Tobias; Moore, Carrie; Sidney, John; Miller, Donald; Tallmadge, Rebecca; Harman, Rebecca M; Oseroff, Carla; Wriston, Amanda; Shabanowitz, Jeffrey; Hunt, Donald F; Osterrieder, Nikolaus; Peters, Bjoern; Antczak, Douglas F; Sette, Alessandro

    2015-11-01

    Here we describe a detailed quantitative peptide-binding motif for the common equine leukocyte antigen (ELA) class I allele Eqca-1*00101, present in roughly 25 % of Thoroughbred horses. We determined a preliminary binding motif by sequencing endogenously bound ligands. Subsequently, a positional scanning combinatorial library (PSCL) was used to further characterize binding specificity and derive a quantitative motif involving aspartic acid in position 2 and hydrophobic residues at the C-terminus. Using this motif, we selected and tested 9- and 10-mer peptides derived from the equine herpesvirus type 1 (EHV-1) proteome for their capacity to bind Eqca-1*00101. PSCL predictions were very efficient, with an receiver operating characteristic (ROC) curve performance of 0.877, and 87 peptides derived from 40 different EHV-1 proteins were identified with affinities of 500 nM or higher. Quantitative analysis revealed that Eqca-1*00101 has a narrow peptide-binding repertoire, in comparison to those of most human, non-human primate, and mouse class I alleles. Peripheral blood mononuclear cells from six EHV-1-infected, or vaccinated but uninfected, Eqca-1*00101-positive horses were used in IFN-γ enzyme-linked immunospot (ELISPOT) assays. When we screened the 87 Eqca-1*00101-binding peptides for T cell reactivity, only one Eqca-1*00101 epitope, derived from the intermediate-early protein ICP4, was identified. Thus, despite its common occurrence in several horse breeds, Eqca-1*00101 is associated with a narrow binding repertoire and a similarly narrow T cell response to an important equine viral pathogen. Intriguingly, these features are shared with other human and macaque major histocompatibility complex (MHC) molecules with a similar specificity for D in position 2 or 3 in their main anchor motif.

  10. Vesicles mimicking normal and cancer cell membranes exhibit differential responses to the cell-penetrating peptide Pep-1.

    Science.gov (United States)

    Almarwani, Bashiyar; Phambu, Esther Nzuzi; Alexander, Christopher; Nguyen, Ha Aimee T; Phambu, Nsoki; Sunda-Meya, Anderson

    2018-06-01

    The cell-penetrating peptide (CPP) Pep-1 presents a great potential in drug delivery due to its intrinsic property to cross plasma membrane. However, its mechanism of entry into the cell remains unresolved. In this study, we compare the selectivity of Pep-1 towards vesicles mimicking normal and cancer cell membranes. The interaction was performed in a wide range of peptide-to-lipid molar ratios using infrared (IR), fluorescence, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. At low peptide concentration, fluorescence experiments show that lipid-phosphatidylserine (PS) seems to enable Pep-1 translocation into cancer cell membrane as evidenced by the blue shift of its maximal emission wavelength. DSC data show that Pep-1 induces segregation of lipids. At high peptide concentration, IR data indicate that the interaction of Pep-1 is relatively stronger with normal cell membrane than with cancer cell membrane through the phosphate groups, while the interaction is weaker with normal cell membrane than with cancer cell membrane through the carbonyl groups. TGA and DSC data reveal that vesicles of normal cell membrane are thermally more stable than vesicles of cancer cell membrane. This suggests that the additional lipid PS included in cancer cell membrane has a destabilizing effect on the membrane structure. SEM images reveal that Pep-1 form superstructures including spherical particles and fibrils in the presence of both model membranes. PS seems to enhance peptide transport across cellular membranes. The biophysical techniques in this study provide valuable insights into the properties of CPPs in drug delivery systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Peptides and Anti-peptide Antibodies for Small and Medium Scale Peptide and Anti-peptide Affinity Microarrays: Antigenic Peptide Selection, Immobilization, and Processing.

    Science.gov (United States)

    Zhang, Fan; Briones, Andrea; Soloviev, Mikhail

    2016-01-01

    This chapter describes the principles of selection of antigenic peptides for the development of anti-peptide antibodies for use in microarray-based multiplex affinity assays and also with mass-spectrometry detection. The methods described here are mostly applicable to small to medium scale arrays. Although the same principles of peptide selection would be suitable for larger scale arrays (with 100+ features) the actual informatics software and printing methods may well be different. Because of the sheer number of proteins/peptides to be processed and analyzed dedicated software capable of processing all the proteins and an enterprise level array robotics may be necessary for larger scale efforts. This report aims to provide practical advice to those who develop or use arrays with up to ~100 different peptide or protein features.

  12. Peptide Inhibitor of Complement C1 (PIC1 Rapidly Inhibits Complement Activation after Intravascular Injection in Rats.

    Directory of Open Access Journals (Sweden)

    Julia A Sharp

    Full Text Available The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1. In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases.

  13. Therapeutic peptides for cancer therapy. Part II - cell cycle inhibitory peptides and apoptosis-inducing peptides.

    Science.gov (United States)

    Raucher, Drazen; Moktan, Shama; Massodi, Iqbal; Bidwell, Gene L

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that arrest the cell cycle by mimicking CDK inhibitors or induce apoptosis directly are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Inhibition of cancer cell proliferation directly using peptides that arrest the cell cycle or induce apoptosis is a promising strategy. Peptides can be designed that interact very specifically with cyclins and/or cyclin-dependent kinases and with members of apoptotic cascades. Use of these peptides is not limited by their design, as a rational approach to peptide design is much less challenging than the design of small molecule inhibitors of specific protein-protein interactions. However, the limitations of peptide therapy lie in the poor pharmacokinetic properties of these large, often charged molecules. Therefore, overcoming the drug delivery hurdles could open the door for effective peptide therapy, thus making an entirely new class of molecules useful as anticancer drugs.

  14. Functional and structural characterization of recombinant dermcidin-1L, a human antimicrobial peptide

    International Nuclear Information System (INIS)

    Lai Yuping; Peng Yifei; Zuo Yi; Li Jun; Huang Jing; Wang Linfa; Wu Zirong

    2005-01-01

    Antimicrobial peptides from human skin are an important component of the innate immune response and play a key role as a first line of defense against infections. One such peptide is the recently discovered dermcidin-1L. To better understand its mechanism and to further investigate its antimicrobial spectrum, recombinant dermcidin-1L was expressed in Escherichia coli as a fusion protein and purified by affinity chromatography. The fusion protein was cleaved by factor Xa protease to produce recombinant dermcidin-1L. Antimicrobial and hemolytic assays demonstrated that dermcidin-1L displayed microbicidal activity against several opportunistic nosocomial pathogens, but no hemolytic activity against human erythrocytes even at concentrations up to 100 μM. Structural studies performed by circular dichroism spectroscopy indicated that the secondary structure of dermcidin-1L was very flexible, and both α-helix and β-sheet structures might be required for the antimicrobial activity. Our results confirmed previous findings indicating that dermcidin-1L could have promising therapeutic potentials and shed new light on the structure-function relationship of dermcidin-1L

  15. Inhibition of Candida albicans Biofilm Formation by the Synthetic Lactoferricin Derived Peptide hLF1-11.

    Science.gov (United States)

    Morici, Paola; Fais, Roberta; Rizzato, Cosmeri; Tavanti, Arianna; Lupetti, Antonella

    2016-01-01

    The aim of this study was to evaluate the in vitro activity of the synthetic peptide hLF1-11 against biofilm produced by clinical isolates of Candida albicans with different fluconazole susceptibility. The antibiofilm activity of the peptide hLF1-11 was assessed in terms of reduction of biofilm cellular density, metabolic activity and sessile cell viability. The extent of morphogenesis in hLF1-11 treated and untreated biofilms was also investigated microscopically. Transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production were analysed by qRT-PCR in hLF1-11 treated and untreated biofilms. Exogenous dibutyryl-cAMP (db-cAMP) was used to rescue morphogenesis in cells exposed to the peptide. The results revealed that hLF1-11 exhibited an inhibitory effect on biofilm formation by all C. albicans isolates tested in a dose-dependent manner, regardless of their fluconazole susceptibility. Visual inspection of treated or untreated biofilm cells with an inverted microscope revealed a significant reduction in hyphal formation by hLF1-11 treated cells, as early as 3 hours of incubation. Moreover, hLF1-11 showed a reduced activity on preadherent cells. hLF1-11 induced the down-regulation of biofilm and hyphal-associated genes, which were predominantly regulated via the Ras1-cAMP-Efg1 pathway. Indeed, exogenous db-cAMP restored morphogenesis in hLF1-11 treated cells. The hLF1-11 peptide significantly inhibited biofilm formation by C. albicans mainly at early stages, interfering with biofilm cellular density and metabolic activity, and affected morphogenesis through the Ras1-cAMP-Efg1 pathway. Our findings provide the first evidence that hLF1-11 could represent a potential candidate for the prevention of biofilm formation by C. albicans.

  16. Inhibition of Candida albicans Biofilm Formation by the Synthetic Lactoferricin Derived Peptide hLF1-11

    Science.gov (United States)

    Morici, Paola; Fais, Roberta; Rizzato, Cosmeri

    2016-01-01

    The aim of this study was to evaluate the in vitro activity of the synthetic peptide hLF1-11 against biofilm produced by clinical isolates of Candida albicans with different fluconazole susceptibility. The antibiofilm activity of the peptide hLF1-11 was assessed in terms of reduction of biofilm cellular density, metabolic activity and sessile cell viability. The extent of morphogenesis in hLF1-11 treated and untreated biofilms was also investigated microscopically. Transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production were analysed by qRT-PCR in hLF1-11 treated and untreated biofilms. Exogenous dibutyryl-cAMP (db-cAMP) was used to rescue morphogenesis in cells exposed to the peptide. The results revealed that hLF1-11 exhibited an inhibitory effect on biofilm formation by all C. albicans isolates tested in a dose-dependent manner, regardless of their fluconazole susceptibility. Visual inspection of treated or untreated biofilm cells with an inverted microscope revealed a significant reduction in hyphal formation by hLF1-11 treated cells, as early as 3 hours of incubation. Moreover, hLF1-11 showed a reduced activity on preadherent cells. hLF1-11 induced the down-regulation of biofilm and hyphal-associated genes, which were predominantly regulated via the Ras1-cAMP-Efg1 pathway. Indeed, exogenous db-cAMP restored morphogenesis in hLF1-11 treated cells. The hLF1-11 peptide significantly inhibited biofilm formation by C. albicans mainly at early stages, interfering with biofilm cellular density and metabolic activity, and affected morphogenesis through the Ras1-cAMP-Efg1 pathway. Our findings provide the first evidence that hLF1-11 could represent a potential candidate for the prevention of biofilm formation by C. albicans. PMID:27902776

  17. Inhibition of Candida albicans Biofilm Formation by the Synthetic Lactoferricin Derived Peptide hLF1-11.

    Directory of Open Access Journals (Sweden)

    Paola Morici

    Full Text Available The aim of this study was to evaluate the in vitro activity of the synthetic peptide hLF1-11 against biofilm produced by clinical isolates of Candida albicans with different fluconazole susceptibility. The antibiofilm activity of the peptide hLF1-11 was assessed in terms of reduction of biofilm cellular density, metabolic activity and sessile cell viability. The extent of morphogenesis in hLF1-11 treated and untreated biofilms was also investigated microscopically. Transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production were analysed by qRT-PCR in hLF1-11 treated and untreated biofilms. Exogenous dibutyryl-cAMP (db-cAMP was used to rescue morphogenesis in cells exposed to the peptide. The results revealed that hLF1-11 exhibited an inhibitory effect on biofilm formation by all C. albicans isolates tested in a dose-dependent manner, regardless of their fluconazole susceptibility. Visual inspection of treated or untreated biofilm cells with an inverted microscope revealed a significant reduction in hyphal formation by hLF1-11 treated cells, as early as 3 hours of incubation. Moreover, hLF1-11 showed a reduced activity on preadherent cells. hLF1-11 induced the down-regulation of biofilm and hyphal-associated genes, which were predominantly regulated via the Ras1-cAMP-Efg1 pathway. Indeed, exogenous db-cAMP restored morphogenesis in hLF1-11 treated cells. The hLF1-11 peptide significantly inhibited biofilm formation by C. albicans mainly at early stages, interfering with biofilm cellular density and metabolic activity, and affected morphogenesis through the Ras1-cAMP-Efg1 pathway. Our findings provide the first evidence that hLF1-11 could represent a potential candidate for the prevention of biofilm formation by C. albicans.

  18. Use of Fructosyl Peptide Oxidase for HbA1c Assay

    Science.gov (United States)

    Yonehara, Satoshi; Inamura, Norio; Fukuda, Miho; Sugiyama, Koji

    2015-01-01

    ARKRAY, Inc developed the world’s first automatic glycohemoglobin analyzer based on HPLC (1981). After that, ARKRAY developed enzymatic HbA1c assay “CinQ HbA1c” with the spread and diversification of HbA1c measurement (2007). CinQ HbA1c is the kit of Clinical Chemistry Analyzer, which uses fructosyl peptide oxidase (FPOX) for a measurement reaction. This report mainly indicates the developmental background, measurement principle, and future of the enzymatic method HbA1c reagent. PMID:25633966

  19. Glucagon-like peptide-1 7-36 amide and peptide YY from the L-cell of the ileal mucosa are potent inhibitors of vagally induced gastric acid secretion in man

    DEFF Research Database (Denmark)

    Wettergren, A; Petersen, H; Orskov, C

    1994-01-01

    BACKGROUND: Glucagon-like peptide (GLP-1) 7-36 amide and peptide YY (PYY) from the L-cell of the ileal mucosa are potent inhibitors of gastric acid secretion in man. It is not clear, however, by which mechanism(s) they inhibit acid secretion. In dogs the inhibitory effect of PYY on acid secretion...

  20. Matrix-assisted laser desorption/ionization time-of-flight and nano-electrospray ionization ion trap mass spectrometric characterization of 1-cyano-2-substituted-benz[f]isoindole derivatives of peptides for fluorescence detection

    DEFF Research Database (Denmark)

    Linnemayr, K; Brückner, A; Körner, R

    1999-01-01

    A series of hexa- to decapeptides (molecular mass range 800-1200) were labeled with naphthalene-2,3-dicarboxaldehyde, which preferentially reacts with the primary amino groups of a peptide. A highly stable peptide conjugate is formed, which allows selective analysis by fluorescence at excitation...... and emission wavelengths of 420 and 490 nm, respectively. After removal of unreacted compounds, the peptide conjugates were characterized by matrix-assisted laser desorption/ionization (MALDI) time-of-flight and nano-electrospray ionization (ESI) ion trap mass spectrometry. They readily form both [M + H]+ ions...... by MALDI and both [M + H]+ and [M + 2H]2+ ions by ESI. Furthermore, the fragmentation behavior of the N-terminally tagged peptides, exhibiting an uncharged N-terminus, was investigated applying post-source decay fragmentation with a curved field reflector and collision-induced dissociation...

  1. Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes

    DEFF Research Database (Denmark)

    Nauck, M A; Vardarli, I; Deacon, C F

    2011-01-01

    The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP......-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency...... with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some...

  2. Analysis of α-helix unfolding in the pine nut peptide Lys-Cys-His-Lys-Pro induced by pulsed electric field.

    Science.gov (United States)

    Xing, Jie; Zhang, Sitian; Zhang, Mingdi; Lin, Songyi

    2017-09-01

    A variety of analytical techniques were applied to explore the effects of pulsed electric field (PEF) on α-helix structural changes in the novel antioxidant peptide Lys-Cys-His-Lys-Pro (KCHKP, 611.76 Da). The relative α-helix content of the KCHKP peptide was significantly altered from 100% to 89.91 ± 0.97% when the electric pulse frequency was 1800 Hz and the field intensity was 10 kV cm -1 . Moreover, the 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2-azinobis diammonium salt (ABTS) radical-scavenging activities of PEF-treated KCHKP were increased from 56.31% ± 0.74% to 84.33% ± 1.23% and from 40.56% ± 0.78% to 51.33% ± 0.27%, respectively. PEF treatment increased peptide linkage stretch vibration and altered hydrogen bonding of KCHKP. The stability of the α-helix structure was influenced by hydrogen bonds within the peptide linkage of KCHKP induced by PEF and was related to changes in antioxidant activity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Atrial Natriuretic Peptide (ANP) in early pregnancy is associated with development of preeclampsia in type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2011-01-01

    The vasoactive markers of cardiac overload Atrial Natriuretic Peptide (ANP) and Brain Natriuretic Peptide (BNP) are elevated in preeclampsia. This study documents higher ANP concentrations as early as at 9 weeks in type 1 diabetic women subsequently developing preeclampsia suggesting...... that preeclampsia is associated with cardiovascular changes in early pregnancy....

  4. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  5. Characterization of amyloid beta peptides from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein.

    Science.gov (United States)

    Pype, Stefan; Moechars, Dieder; Dillen, Lieve; Mercken, Marc

    2003-02-01

    Alzheimer's disease (AD) is marked by the presence of neurofibrillary tangles and amyloid plaques in the brain of patients. To study plaque formation, we report on further quantitative and qualitative analysis of human and mouse amyloid beta peptides (Abeta) from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein (APP). Using enzyme-linked immunosorbant assays (ELISAs) specific for either human or rodent Abeta, we found that the peptides from both species aggregated to form plaques. The ratios of deposited Abeta1-42/1-40 were in the order of 2-3 for human and 8-9 for mouse peptides, indicating preferential deposition of Abeta42. We also determined the identity and relative levels of other Abeta variants present in protein extracts from soluble and insoluble brain fractions. This was done by combined immunoprecipitation and mass spectrometry (IP/MS). The most prominent peptides truncated either at the carboxyl- or the amino-terminus were Abeta1-38 and Abeta11-42, respectively, and the latter was strongly enriched in the extracts of deposited peptides. Taken together, our data indicate that plaques of APP-London transgenic mice consist of aggregates of multiple human and mouse Abeta variants, and the human variants that we identified were previously detected in brain extracts of AD patients.

  6. Aminosilanes derived from 1H-benzimidazole-2(3H)-thione

    International Nuclear Information System (INIS)

    Palomo-Molina, Juliana; García-Báez, Efrén V.; Contreras, Rosalinda; Pineda-Urbina, Kayim; Ramos-Organillo, Angel

    2015-01-01

    In two trimethylsilyl-substituted 1H-benzimidazole-2(3H)-thiones, noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe 3 groups form helicoidal arrangements in one, and dimerization results in the formation of R s 2 (8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings, in the second compound. Two new molecular structures, namely 1,3-bis(trimethylsilyl)-1H-benzimidazole-2(3H)-thione, C 13 H 22 N 2 SSi 2 , (2), and 1-trimethylsilyl-1H-benzimidazole-2(3H)-thione, C 10 H 14 N 2 SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe 3 groups form helicoidal arrangements in (2). Dimerization of (3) results in the formation of R 2 2 (8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings

  7. Efficacy of antibacterial peptides against peptide-resistant MRSA is restored by permeabilisation of bacteria membranes

    Directory of Open Access Journals (Sweden)

    Joshua Thomas Ravensdale

    2016-11-01

    Full Text Available Clinical application of antimicrobial peptides, as with conventional antibiotics, may be compromised by the development of bacterial resistance. This study investigated antimicrobial peptide resistance in methicillin resistant Staphylococcus aureus, including aspects related to the resilience of the resistant bacteria towards the peptides, the stability of resistance when selection pressures are removed, and whether resistance can be overcome by using the peptides with other membrane-permeabilising agents. Genotypically variant strains of S. aureus became equally resistant to the antibacterial peptides melittin and bac8c when grown in sub-lethal concentrations. Subculture of a melittin-resistant strain without melittin for 8 days lowered the minimal lethal concentration of the peptide from 170 µg ml-1 to 30 g ml-1. Growth for 24 h in 12 g ml-1 melittin restored the MLC to 100 g ml-1. Flow cytometry analysis of cationic fluorophore binding to melittin-naïve and melittin-resistant bacteria revealed that resistance coincided with decreased binding of cationic molecules, suggesting a reduction in nett negative charge on the membrane. Melittin was haemolytic at low concentrations but the truncated analogue of melittin, mel12-26, was confirmed to lack haemolytic activity. Although a previous report found that mel12-26 retained full bactericidal activity, we found it to lack significant activity when added to culture medium. However, electroporation in the presence of 50 µg ml-1 of mel12-26, killed 99.3% of the bacteria. Similarly, using a low concentration of the non-ionic detergent Triton X-100 to permeabilize bacteria to mel12-26 markedly increased its bactericidal activity. The observation that bactericidal activity of the non-membranolytic peptide mel12-26 was enhanced when the bacterial membrane was permeablised by detergents or electroporation, suggests that its principal mechanism in reducing bacterial survival may be through

  8. In silico design of cyclic peptides as influenza virus, a subtype H1N1 ...

    African Journals Online (AJOL)

    Cyclic peptides can be used to make new antiviral drug design especially to inhibit neuraminidase activity by using 'structure-based design' method. Based on molecular docking, new antiviral drug designs have been found. They are DNY, NNY, DDY, DYY, RRR, RPR, RRP and LRL. These cyclic peptides showed better ...

  9. Receptor binding properties and antinociceptive effects of chimeric peptides consisting of a micro-opioid receptor agonist and an ORL1 receptor antagonist.

    Science.gov (United States)

    Kawano, Susumu; Ito, Risa; Nishiyama, Miharu; Kubo, Mai; Matsushima, Tomoko; Minamisawa, Motoko; Ambo, Akihiro; Sasaki, Yusuke

    2007-07-01

    Receptor binding properties and antinociceptive activities of chimeric peptides linked by spacers were investigated. The peptides consisted of the micro-opioid receptor ligand dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH(2)) or its analog YRFB (Tyr-D-Arg-Phe-betaAla-NH(2)) linked to the ORL1 receptor ligand Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) (Ac-RYYRIK-NH(2)). All chimeric peptides were found to possess high receptor binding affinities for both micro-opioid and ORL1 receptors in mouse brain membranes although their binding affinities for both receptors in spinal membranes were significantly lower. Among them, chimeric peptide 2, which consists of dermorphin and Ac-RYYRIK-NH(2) connected by a long spacer, had the highest binding affinity towards both receptors. In the tail-flick test following intrathecal (i.t.) administration to mice, all chimeric peptides showed potent and dose-dependent antinociceptive activities with an ED(50) of 1.34-4.51 (pmol/mouse), nearly comparable to dermorphin alone (ED(50); 1.08 pmol/mouse). In contrast to their micro-opioid receptor binding profiles, intracerebroventricular (i.c.v.) administration of the chimeric peptides resulted in much less potent antinociceptive activity (ED(50) 5.55-100peptides, and the regulation of mu-opioid receptor-mediated antinociception in brain. The present chimeric peptides may be useful as pharmacological tools for studies on micro-opioid receptor/ORL1 receptor heterodimers.

  10. Quantitative (23) Na MRI of human knee cartilage using dual-tuned (1) H/(23) Na transceiver array radiofrequency coil at 7 tesla.

    Science.gov (United States)

    Moon, Chan Hong; Kim, Jung-Hwan; Zhao, Tiejun; Bae, Kyongtae Ty

    2013-11-01

    To develop quantitative dual-tuned (DT) (1) H/(23) Na MRI of human knee cartilage in vivo at 7 Tesla (T). A sensitive (23) Na transceiver array RF coil was developed at 7T. B1 fields generated by the transceiver array coil were characterized and corrected in the (23) Na images. Point spread function (PSF) of the (23) Na images was measured, and the signal decrease due to partial-volume-effect was compensated in [(23) Na] quantification of knee cartilage. SNR and [(23) Na] in anterior femoral cartilage were measured from seven healthy subjects. SNR of (23) Na image with the transceiver array coil was higher than that of birdcage coil. SNR in the cartilage at 2-mm isotropic resolution was 26.80 ± 3.69 (n = 7). B1 transmission and reception fields produced by the DT coil at 7T were similar to each other. Effective full-width-half-maximum of (23) Na image was ∼5 mm at 2-mm resolution. Mean [(23) Na] was 288.13 ± 29.50 mM (n = 7) in the anterior femoral cartilage of normal subjects. We developed a new high-sensitivity (23) Na RF coil for knee MRI at 7T. Our (1) H/(23) Na MRI allowed quantitative measurement of [(23) Na] in knee cartilage by measuring PSF and cartilage thickness from (23) Na and (1) H image, respectively. Copyright © 2013 Wiley Periodicals, Inc.

  11. Conformational changes of the amyloid beta-peptide (1-40) adsorbed on solid surfaces

    NARCIS (Netherlands)

    Giacomelli, CE; Norde, W

    2005-01-01

    The conformational change of the 39-43 residues of the amyloid beta-peptide (A beta) toward a beta-sheet enriched state promotes self-aggregation of the peptide molecules and constitutes the major peptide component of the amyloid plaques in Alzheimer patients. The crucial question behind the

  12. Conformational changes of the amyloid beta-peptide (1-40) adsorbed on solid surfaces

    NARCIS (Netherlands)

    Giacomelli, C.E.; Norde, W.

    2005-01-01

    The conformational change of the 39-43 residues of the amyloid beta -peptide (A beta) toward a beta -sheet enriched state promotes self-aggregation of the peptide molecules and constitutes the major peptide component of the amyloid plaques in Alzheimer patients. The crucial question behind the

  13. Effect of TFE on the Helical Content of AK17 and HAL-1 Peptides: Theoretical Insights into the Mechanism of Helix Stabilization.

    Science.gov (United States)

    Vymětal, Jiří; Bednárová, Lucie; Vondrášek, Jiří

    2016-02-18

    Fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) are among the most frequently used cosolvents in experiment studies of peptides. They have significant effects on secondary structure and a particularly strong promotion of α-helix is induced by TFE. In this study we validated recently proposed force field parameters for TFE in molecular dynamics simulations with two model peptides-alanine-rich AK-17 and antimicrobial peptide halictine-1 (HAL-1). In the case of HAL-1, we characterized the effect of TFE on this peptide experimentally by ECD spectroscopy. Our TFE model in question reproduced the helix-promoting effect of TFE and provided insight into the mechanisms of TFE action on peptides. Our simulations confirmed the preferential interaction of TFE molecules with α-helices, although the TFE molecules accumulate in the vicinity of the peptides in various conformations. Moreover, we observed a significant effect of TFE on the thermodynamics of the helix-coil transition and a change in local conformational preferences in the unfolded (coil) state induced by TFE. In addition, our simulation-based analysis suggests that different mechanisms participate in helix stabilization in both model peptides in water and TFE solution. Our results thus support the picture of complex TFE action on peptides that is further diversified by the identity and intrinsic properties of the peptide.

  14. Membrane-tethered peptides patterned after the TRP domain (TRPducins) selectively inhibit TRPV1 channel activity.

    Science.gov (United States)

    Valente, Pierluigi; Fernández-Carvajal, Asia; Camprubí-Robles, María; Gomis, Ana; Quirce, Susana; Viana, Félix; Fernández-Ballester, Gregorio; González-Ros, José M; Belmonte, Carlos; Planells-Cases, Rosa; Ferrer-Montiel, Antonio

    2011-05-01

    The transient receptor potential vanilloid 1 (TRPV1) channel is a thermosensory receptor implicated in diverse physiological and pathological processes. The TRP domain, a highly conserved region in the C terminus adjacent to the internal channel gate, is critical for subunit tetramerization and channel gating. Here, we show that cell-penetrating, membrane-anchored peptides patterned after this protein domain are moderate and selective TRPV1 antagonists both in vitro and in vivo, blocking receptor activity in intact rat primary sensory neurons and their peripheral axons with mean decline time of 30 min. The most potent lipopeptide, TRP-p5, blocked all modes of TRPV1 gating with micromolar efficacy (IC(50)100 μM). TRP-p5 did not affect the capsaicin sensitivity of the vanilloid receptor. Our data suggest that TRP-p5 interferes with protein-protein interactions at the level of the TRP domain that are essential for the "conformational" change that leads to gate opening. Therefore, these palmitoylated peptides, which we termed TRPducins, are noncompetitive, voltage-independent, sequence-specific TRPV1 blockers. Our findings indicate that TRPducin-like peptides may embody a novel molecular strategy that can be exploited to generate a selective pharmacological arsenal for the TRP superfamily of ion channels.

  15. Peptide aptamers as new tools to modulate clathrin-mediated internalisation--inhibition of MT1-MMP internalisation.

    Science.gov (United States)

    Wickramasinghe, Rochana D; Ko Ferrigno, Paul; Roghi, Christian

    2010-07-23

    Peptide aptamers are combinatorial protein reagents that bind to targets with a high specificity and a strong affinity thus providing a molecular tool kit for modulating the function of their targets in vivo. Here we report the isolation of a peptide aptamer named swiggle that interacts with the very short (21 amino acid long) intracellular domain of membrane type 1-metalloproteinase (MT1-MMP), a key cell surface protease involved in numerous and crucial physiological and pathological cellular events. Expression of swiggle in mammalian cells was found to increase the cell surface expression of MT1-MMP by impairing its internalisation. Swiggle interacts with the LLY573 internalisation motif of MT1-MMP intracellular domain, thus disrupting the interaction with the mu2 subunit of the AP-2 internalisation complex required for endocytosis of the protease. Interestingly, swiggle-mediated inhibition of MT1-MMP clathrin-mediated internalisation was also found to promote MT1-MMP-mediated cell migration. Taken together, our results provide further evidence that peptide aptamers can be used to dissect molecular events mediated by individual protein domains, in contrast to the pleiotropic effects of RNA interference techniques.

  16. Nonribosomal Peptide Synthetase Genes pesL and pes1 Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

    DEFF Research Database (Denmark)

    O'Hanlon, Karen A.; Gallagher, Lorna; Schrettl, Markus

    2012-01-01

    The identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen, Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end produc...

  17. Molecular Docking Simulation of Neuraminidase Influenza A Subtype H1N1 with Potential Inhibitor of Disulfide Cyclic Peptide (DNY, NNY, LRL)

    Science.gov (United States)

    Putra, R. P.; Imaniastuti, R.; Nasution, M. A. F.; Kerami, Djati; Tambunan, U. S. F.

    2018-04-01

    Oseltamivir resistance as an inhibitor of neuraminidase influenza A virus subtype H1N1 has been reported lately. Therefore, to solve this problem, several kinds of research has been conducted to design and discover disulfide cyclic peptide ligands through molecular docking method, to find the potential inhibitors for neuraminidase H1N1 which then can disturb the virus replication. This research was studied and evaluated the interaction of ligands toward enzyme using molecular docking simulation, which was performed on three disulfide cyclic peptide inhibitors (DNY, LRL, and NNT), along with oseltamivir and zanamivir as the standard ligands using MOE 2008.10 software. The docking simulation shows that all disulfide cyclic peptide ligands have lower Gibbs free binding energies (ΔGbinding) than the standard ligands, with DNY ligand has the lowest ΔGbinding at -7.8544 kcal/mol. Furthermore, these ligands were also had better molecular interactions with neuraminidase than the standards, owing by the hydrogen bonds that were formed during the docking simulation. In the end, we concluded that DNY, LRL and NNT ligands have the potential to be developed as the inhibitor of neuraminidase H1N1.

  18. Peptide aldehyde inhibitors of bacterial peptide deformylases.

    Science.gov (United States)

    Durand, D J; Gordon Green, B; O'Connell, J F; Grant, S K

    1999-07-15

    Bacterial peptide deformylases (PDF, EC 3.5.1.27) are metalloenzymes that cleave the N-formyl groups from N-blocked methionine polypeptides. Peptide aldehydes containing a methional or norleucinal inhibited recombinant peptide deformylase from gram-negative Escherichia coli and gram-positive Bacillus subtilis. The most potent inhibitor was calpeptin, N-CBZ-Leu-norleucinal, which was a competitive inhibitor of the zinc-containing metalloenzymes, E. coli and B. subtilis PDF with Ki values of 26.0 and 55.6 microM, respectively. Cobalt-substituted E. coli and B. subtilis deformylases were also inhibited by these aldehydes with Ki values for calpeptin of 9.5 and 12.4 microM, respectively. Distinct spectral changes were observed upon binding of calpeptin to the Co(II)-deformylases, consistent with the noncovalent binding of the inhibitor rather than the formation of a covalent complex. In contrast, the chelator 1,10-phenanthroline caused the time-dependent inhibition of B. subtilis Co(II)-PDF activity with the loss of the active site metal. The fact that calpeptin was nearly equipotent against deformylases from both gram-negative and gram-positive bacterial sources lends further support to the idea that a single deformylase inhibitor might have broad-spectrum antibacterial activity. Copyright 1999 Academic Press.

  19. A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

    Science.gov (United States)

    Kakimi, Kazuhiro; Isobe, Midori; Uenaka, Akiko; Wada, Hisashi; Sato, Eiichi; Doki, Yuichiro; Nakajima, Jun; Seto, Yasuyuki; Yamatsuji, Tomoki; Naomoto, Yoshio; Shiraishi, Kenshiro; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Oka, Mikio; Pan, Linda; Hoffman, Eric W; Old, Lloyd J; Nakayama, Eiichi

    2011-12-15

    We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients. Copyright © 2011 UICC.

  20. The Equine PeptideAtlas

    DEFF Research Database (Denmark)

    Bundgaard, Louise; Jacobsen, Stine; Sørensen, Mette Aamand

    2014-01-01

    Progress in MS-based methods for veterinary research and diagnostics is lagging behind compared to the human research, and proteome data of domestic animals is still not well represented in open source data repositories. This is particularly true for the equine species. Here we present a first...... Equine PeptideAtlas encompassing high-resolution tandem MS analyses of 51 samples representing a selection of equine tissues and body fluids from healthy and diseased animals. The raw data were processed through the Trans-Proteomic Pipeline to yield high quality identification of proteins and peptides....... The current release comprises 24 131 distinct peptides representing 2636 canonical proteins observed at false discovery rates of 0.2% at the peptide level and 1.4% at the protein level. Data from the Equine PeptideAtlas are available for experimental planning, validation of new datasets, and as a proteomic...

  1. Isolation, chemical and functional characterization of several new K(+)-channel blocking peptides from the venom of the scorpion Centruroides tecomanus.

    Science.gov (United States)

    Olamendi-Portugal, Timoteo; Bartok, Adam; Zamudio-Zuñiga, Fernando; Balajthy, Andras; Becerril, Baltazar; Panyi, Gyorgy; Possani, Lourival D

    2016-06-01

    Six new peptides were isolated from the venom of the Mexican scorpion Centruroides tecomanus; their primary structures were determined and the effects on ion channels were verified by patch-clamp experiments. Four are K(+)-channel blockers of the α-KTx family, containing 32 to 39 amino acid residues, cross-linked by three disulfide bonds. They all block Kv1.2 in nanomolar concentrations and show various degree of selectivity over Kv1.1, Kv1.3, Shaker and KCa3.1 channels. One peptide has 42 amino acids cross-linked by four disulfides; it blocks ERG-channels and belongs to the γ-KTx family. The sixth peptide has only 32 amino acid residues, three disulfide bonds and has no effect on the ion-channels assayed. It also does not have antimicrobial activity. Systematic numbers were assigned (time of elution on HPLC): α-KTx 10.4 (time 24.1); α-KTx 2.15 (time 26.2); α-KTx 2.16 (time 23.8); α-KTx 2.17 (time 26.7) and γ-KTx 1.9 (elution time 29.6). A partial proteomic analysis of the short chain basic peptides of this venom, which elutes on carboxy-methyl-cellulose column fractionation, is included. The pharmacological properties of the peptides described in this study may provide valuable tools for understanding the structure-function relationship of K(+) channel blocking scorpion toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Prediction of Impending Type 1 Diabetes through Automated Dual-Label Measurement of Proinsulin:C-Peptide Ratio.

    Directory of Open Access Journals (Sweden)

    Annelien Van Dalem

    Full Text Available The hyperglycemic clamp test, the gold standard of beta cell function, predicts impending type 1 diabetes in islet autoantibody-positive individuals, but the latter may benefit from less invasive function tests such as the proinsulin:C-peptide ratio (PI:C. The present study aims to optimize precision of PI:C measurements by automating a dual-label trefoil-type time-resolved fluorescence immunoassay (TT-TRFIA, and to compare its diagnostic performance for predicting type 1 diabetes with that of clamp-derived C-peptide release.Between-day imprecision (n = 20 and split-sample analysis (n = 95 were used to compare TT-TRFIA (AutoDelfia, Perkin-Elmer with separate methods for proinsulin (in-house TRFIA and C-peptide (Elecsys, Roche. High-risk multiple autoantibody-positive first-degree relatives (n = 49; age 5-39 were tested for fasting PI:C, HOMA2-IR and hyperglycemic clamp and followed for 20-57 months (interquartile range.TT-TRFIA values for proinsulin, C-peptide and PI:C correlated significantly (r2 = 0.96-0.99; P<0.001 with results obtained with separate methods. TT-TRFIA achieved better between-day %CV for PI:C at three different levels (4.5-7.1 vs 6.7-9.5 for separate methods. In high-risk relatives fasting PI:C was significantly and inversely correlated (rs = -0.596; P<0.001 with first-phase C-peptide release during clamp (also with second phase release, only available for age 12-39 years; n = 31, but only after normalization for HOMA2-IR. In ROC- and Cox regression analysis, HOMA2-IR-corrected PI:C predicted 2-year progression to diabetes equally well as clamp-derived C-peptide release.The reproducibility of PI:C benefits from the automated simultaneous determination of both hormones. HOMA2-IR-corrected PI:C may serve as a minimally invasive alternative to the more tedious hyperglycemic clamp test.

  3. Identifying immunogenic CD4+ T-cell epitopes of Myeloid cell leukemia 1 using overlapping 20-mer peptides spanning the whole protein

    DEFF Research Database (Denmark)

    Woodworth, Joshua S.; Agger, Else Marie; Hansen, Paul Robert

    2015-01-01

    ) small-molecule inhibitors [6] and (iii) peptide inhibitors [7]. In recent years, therapeutic vaccination with synthetic peptides derived from anti-apoptotic proteins such as Mcl-1 has emerged as a promising strategy against hematological cancers. In this study, 34 overlapping 20-mer peptides, spanning...

  4. Naturally processed measles virus peptide eluted from class II HLA-DRB1*03 recognized by T lymphocytes from human blood

    International Nuclear Information System (INIS)

    Ovsyannikova, Inna G.; Johnson, Kenneth L.; Naylor, Stephen; Muddiman, David C.; Poland, Gregory A.

    2003-01-01

    This is the first report of the direct identification of a HLA-DRB1*03 measles-derived peptide from measles virus infected EBV-transformed B cells. We purified HLA-DR3-peptide complexes from EBV-B cells infected with measles virus (Edmonston strain) and sequenced the HLA-DR3-peptides by mass spectrometry. A class II peptide, derived from a measles phosphoprotein, ASDVETAEGGEIHELLRLQ (P1, residues 179-197), exhibited the capacity to stimulate peripheral blood mononuclear cells to proliferate. Our data provides direct evidence that the antigenic peptide of measles virus was processed by antigen-presenting cells, presented in the context of HLA class II molecules, and was recognized by peripheral blood T cells from healthy individuals previously immunized with measles vaccine. The approach described herein provides a useful methodology for the future identification of HLA-presented pathogen-derived epitopes using mass spectrometry. The study of cell-mediated immune responses to the measles-derived peptide in immune persons should provide significant insight into the design and development of new vaccines

  5. Discordant expression of pro-B-type and pro-C-type natriuretic peptide in newborn infants of mothers with type 1 diabetes

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, Lars Bo; Nielsen, Søren Junge

    2007-01-01

    CNP-derived peptides in newborn infants. METHODS: Plasma concentrations of proCNP-derived peptides were measured in umbilical cord plasma and human placental tissue extracts using sequence-specific radioimmunoassays raised against N-terminal and C-terminal proCNP regions, respectively. RESULTS: The median pro...... in umbilical cord plasma compared to adult plasma (4.6 vs. 1.1), which parallels our earlier findings for proBNP and BNP peptides. CONCLUSIONS: There is a discordant expression of CNP and BNP peptides in newborn infants of mothers with diabetes. Moreover, fetal metabolism of proCNP and CNP appears to differ...

  6. Insect Peptides - Perspectives in Human Diseases Treatment.

    Science.gov (United States)

    Chowanski, Szymon; Adamski, Zbigniew; Lubawy, Jan; Marciniak, Pawel; Pacholska-Bogalska, Joanna; Slocinska, Malgorzata; Spochacz, Marta; Szymczak, Monika; Urbanski, Arkadiusz; Walkowiak-Nowicka, Karolina; Rosinski, Grzegorz

    2017-01-01

    Insects are the largest and the most widely distributed group of animals in the world. Their diversity is a source of incredible variety of different mechanisms of life processes regulation. There are many agents that regulate immunology, reproduction, growth and development or metabolism. Hence, it seems that insects may be a source of numerous substances useful in human diseases treatment. Especially important in the regulation of insect physiology are peptides, like neuropeptides, peptide hormones or antimicrobial peptides. There are two main aspects where they can be helpful, 1) Peptides isolated from insects may become potential drugs in therapy of different diseases, 2) A lot of insect peptide hormones show structural or functional homology to mammalian peptide hormones and the comparative studies may give a new look on human disorders. In our review we focused on three group of insect derived peptides: 1) immune-active peptides, 2) peptide hormones and 3) peptides present in venoms. In our review we try to show the considerable potential of insect peptides in searching for new solutions for mammalian diseases treatment. We summarise the knowledge about properties of insect peptides against different virulent agents, anti-inflammatory or anti-nociceptive properties as well as compare insect and mammalian/vertebrate peptide endocrine system to indicate usefulness of knowledge about insect peptide hormones in drug design. The field of possible using of insect delivered peptide to therapy of various human diseases is still not sufficiently explored. Undoubtedly, more attention should be paid to insects due to searching new drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. 1-Propyl-1H-indole-2,3-dione

    Directory of Open Access Journals (Sweden)

    Fatima Zahrae Qachchachi

    2016-04-01

    Full Text Available In the title compound, C11H11NO2, the 1H-indole-2,3-dione unit is essentially planar, with an r.m.s. deviation of 0.0387 (13 Å. This plane makes a dihedral angle of 72.19 (17° with the plane of the propyl substituent. In the crystal, chains propagating along the b axis are formed through C—H...O hydrogen bonds.

  8. Peptide array-based screening of human mesenchymal stem cell-adhesive peptides derived from fibronectin type III domain

    International Nuclear Information System (INIS)

    Okochi, Mina; Nomura, Shigeyuki; Kaga, Chiaki; Honda, Hiroyuki

    2008-01-01

    Human mesenchymal stem cell-adhesive peptides were screened based on the amino acid sequence of fibronectin type III domain 8-11 (FN-III 8-11 ) using a peptide array synthesized by the Fmoc-chemistry. Using hexameric peptide library of FN-III 8-11 scan, we identified the ALNGR (Ala-Leu-Asn-Gly-Arg) peptide that induced cell adhesion as well as RGDS (Arg-Gly-Asp-Ser) peptide. After incubation for 2 h, approximately 68% of inoculated cells adhere to the ALNGR peptide disk. Adhesion inhibition assay with integrin antibodies showed that the ALNGR peptide interacts with integrin β1 but not with αvβ3, indicating that the receptors for ALNGR are different from RGDS. Additionally, the ALNGR peptide expressed cell specificities for adhesion: cell adhesion was promoted for fibroblasts but not for keratinocytes or endotherial cells. The ALNGR peptide induced cell adhesion and promoted cell proliferation without changing its property. It is therefore useful for the construction of functional biomaterials

  9. Chronopotentiometric determination of redox states of peptides

    Czech Academy of Sciences Publication Activity Database

    Dorčák, Vlastimil; Paleček, Emil

    2007-01-01

    Roč. 19, č. 23 (2007), s. 2405-2412 ISSN 1040-0397 R&D Projects: GA AV ČR(CZ) IAA500040513; GA ČR(CZ) GA301/07/0490; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : peptide redox states * constant current chronopotentiometry * catalytic hydrogen evolution Subject RIV: BO - Biophysics Impact factor: 2.949, year: 2007

  10. Screening of random peptide library of hemagglutinin from pandemic 2009 A(H1N1 influenza virus reveals unexpected antigenically important regions.

    Directory of Open Access Journals (Sweden)

    Wanghui Xu

    Full Text Available The antigenic structure of the membrane protein hemagglutinin (HA from the 2009 A(H1N1 influenza virus was dissected with a high-throughput screening method using complex antisera. The approach involves generating yeast cell libraries displaying a pool of random peptides of controllable lengths on the cell surface, followed by one round of fluorescence-activated cell sorting (FACS against antisera from mouse, goat and human, respectively. The amino acid residue frequency appearing in the antigenic peptides at both the primary sequence and structural level was determined and used to identify "hot spots" or antigenically important regions. Unexpectedly, different antigenic structures were seen for different antisera. Moreover, five antigenic regions were identified, of which all but one are located in the conserved HA stem region that is responsible for membrane fusion. Our findings are corroborated by several recent studies on cross-neutralizing H1 subtype antibodies that recognize the HA stem region. The antigenic peptides identified may provide clues for creating peptide vaccines with better accessibility to memory B cells and better induction of cross-neutralizing antibodies than the whole HA protein. The scheme used in this study enables a direct mapping of the antigenic regions of viral proteins recognized by antisera, and may be useful for dissecting the antigenic structures of other viral proteins.

  11. The Use of an IL-1 Receptor Antagonist Peptide to Control Inflammation in the Treatment of Corneal Limbal Epithelial Stem Cell Deficiency

    Directory of Open Access Journals (Sweden)

    E. Fok

    2015-01-01

    Full Text Available Corneal limbal stem cell deficiency (LSCD may be treated using ex vivo limbal epithelial stem cells (LESCs derived from cadaveric donor tissue. However, continuing challenges exist around tissue availability, inflammation, and transplant rejection. Lipopolysaccharide (LPS or recombinant human IL-1β stimulated primary human keratocyte and LESC models were used to investigate the anti-inflammatory properties of a short chain, IL-1 receptor antagonist peptide for use in LESC sheet growth to control inflammation. The peptide was characterized using mass spectroscopy and high performance liquid chromatography. Peptide cytotoxicity, patterns of cell cytokine expression in response to LPS or IL-1β stimulation, and peptide suppression of this response were investigated by MTS/LDH assays, ELISA, and q-PCR. Cell differences in LPS stimulated toll-like receptor 4 expression were investigated using immunocytochemistry. A significant reduction in rIL-1β stimulated inflammatory cytokine production occurred following LESC and keratocyte incubation with anti-inflammatory peptide and in LPS stimulated IL-6 and IL-8 production following keratocyte incubation with peptide (1 mg/mL P<0.05. LESCs produced no cytokine response to LPS stimulation and showed no TLR4 expression. The peptide supported LESC growth when adhered to a silicone hydrogel contact lens indicating potential use in improved LESC grafting through suppression of inflammation.

  12. Insulin-like growth factor 1 (IGF1) and its active peptide (1-3)IGF1 enhance the expression of synaptic markers in neuronal circuits through different cellular mechanisms.

    LENUS (Irish Health Repository)

    Corvin, Aiden P

    2012-06-27

    Insulin-like growth factor-1 (IGF1) and its active peptide (1-3)IGF1 modulate brain growth and plasticity and are candidate molecules for treatment of brain disorders. IGF1 N-terminal portion is naturally cleaved to generate the tri-peptide (1-3)IGF1 (glycine-praline-glutamate). IGF1 and (1-3)IGF have been proposed as treatment for neuropathologies, yet their effect on nerve cells has not been directly compared. In this study we examine the effects of IGF1 and (1-3)IGF1 in primary cortical cultures and measure the expression levels of markers for intracellular pathways and synaptic function. We find that both treatments activate the IGF1 receptor and enhance the expression of synaptic markers, however, they activate different intracellular pathways. Furthermore, (1-3)IGF1 administration increases the expression of endogenous IGF1, suggesting a direct interaction between the two molecules. The results show that the two molecules increase the expression of synaptic proteins through activating different cellular mechanisms.

  13. Analogues of the Frog-skin Antimicrobial Peptide Temporin 1Tb Exhibit a Wider Spectrum of Activity and a Stronger Antibiofilm Potential as Compared to the Parental Peptide

    Science.gov (United States)

    Grassi, Lucia; Maisetta, Giuseppantonio; Maccari, Giuseppe; Esin, Semih; Batoni, Giovanna

    2017-04-01

    The frog skin-derived peptide Temporin 1Tb (TB) has gained increasing attention as novel antimicrobial agent for the treatment of antibiotic-resistant and/or biofilm-mediated infections. Nevertheless, such a peptide possesses a preferential spectrum of action against Gram-positive bacteria. In order to improve the therapeutic potential of TB, the present study evaluated the antibacterial and antibiofilm activities of two TB analogues against medically relevant bacterial species. Of the two analogues, TB_KKG6A has been previously described in the literature, while TB_L1FK is a new analogue designed by us through statistical-based computational strategies. Both TB analogues displayed a faster and stronger bactericidal activity than the parental peptide, especially against Gram-negative bacteria in planktonic form. Differently from the parental peptide, TB_KKG6A and TB_L1FK were able to inhibit the formation of Staphylococcus aureus biofilms by more than 50% at 12 μM, while only TB_KKG6A prevented the formation of Pseudomonas aeruginosa biofilms at 24 μM. A marked antibiofilm activity against preformed biofilms of both bacterial species was observed for the two TB analogues when used in combination with EDTA. Analysis of synergism at the cellular level suggested that the antibiofilm activity exerted by the peptide-EDTA combinations against mature biofilms might be due mainly to a disaggregating effect on the extracellular matrix in the case of S. aureus, and to a direct activity on biofilm-embedded cells in the case of P. aeruginosa. Both analogues displayed a low hemolytic effect at the active concentrations and, overall, TB_L1FK resulted less cytotoxic towards mammalian cells. Collectively, the results obtained demonstrated that subtle changes in the primary sequence of TB may provide TB analogues that, used alone or in combination with adjuvant molecules such as EDTA, exhibit promising features against both planktonic and biofilm cells of medically relevant

  14. Effects of prepartum fat supplementation on plasma concentrations of glucagon-like peptide-1, peptide YY, adropin, insulin, and leptin in periparturient dairy cows.

    Science.gov (United States)

    Zapata, Rizaldy C; Salehi, Reza; Ambrose, Divakar J; Chelikani, Prasanth K

    2015-10-01

    Dietary fat supplementation during the periparturient period is one strategy to increase energy intake and attenuate the degree of negative energy balance during early lactation; however, little is known of the underlying hormonal and metabolic adaptations. We evaluated the effects of prepartum fat supplementation on energy-balance parameters and plasma concentrations of glucagon-like peptide-1, peptide tyrosine-tyrosine (PYY), adropin, insulin, leptin, glucose, nonesterified fatty acid, and β-hydroxybutyric acid in dairy cows. Twenty-four pregnant dairy cows were randomized to diets containing either rolled canola or sunflower seed at 8% of dry matter, or no oilseed supplementation, during the last 5 wk of gestation and then assigned to a common lactation diet postpartum. Blood samples were collected at -2, +2, and +14 h relative to feeding, at 2 wk after the initiation of the diets, and at 2 wk postpartum. Dietary canola and sunflower supplementation alone did not affect energy balance, body weight, and plasma concentrations of glucagon-like peptide-1, PYY, adropin, insulin, leptin, nonesterified fatty acid, and β-hydroxybutyric acid; however, canola decreased and sunflower tended to decrease dry matter intake. We also observed that the physiological stage had a significant, but divergent, effect on circulating hormones and metabolite concentrations. Plasma glucagon-like peptide-1, PYY, adropin, nonesterified fatty acid, and β-hydroxybutyric acid concentrations were greater postpartum than prepartum, whereas glucose, insulin, leptin, body weight, and energy balance were greater prepartum than postpartum. Furthermore, the interaction of treatment and stage was significant for leptin and adropin, and tended toward significance for PYY and insulin; only insulin exhibited an apparent postprandial increase. Postpartum PYY concentrations exhibited a strong negative correlation with body weight, suggesting that PYY may be associated with body weight regulation during

  15. Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.

    Directory of Open Access Journals (Sweden)

    Pei-Ciao Tang

    Full Text Available Cadherin 23 (CDH23, a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1 the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2 the interaction is crucial for normal mechanotransduction and morphology of hair bundles.

  16. Impact of exogenous hyperglucagonemia on postprandial concentrations of gastric inhibitory polypeptide and glucagon-like peptide-1 in humans

    DEFF Research Database (Denmark)

    Meier, Juris J; Ritter, Peter R; Jacob, Alexandra

    2010-01-01

    Postprandial secretion of glucagon-like peptide 1 (GLP-1) has been found diminished in some patients with type 2 diabetes mellitus (T2DM) and high glucagon concentrations. We examined the effects of exogenous glucagon on the release of incretin hormones.......Postprandial secretion of glucagon-like peptide 1 (GLP-1) has been found diminished in some patients with type 2 diabetes mellitus (T2DM) and high glucagon concentrations. We examined the effects of exogenous glucagon on the release of incretin hormones....

  17. Aminosilanes derived from 1H-benzimidazole-2(3H)-thione

    Energy Technology Data Exchange (ETDEWEB)

    Palomo-Molina, Juliana [Facultad de Ciencias Químicas, Universidad de Colima, Carretera Coquimatlán-Colima, Coquimatlán Colima 28400 (Mexico); García-Báez, Efrén V. [Unidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional, Avenida Acueducto s/n, Barrio La Laguna Ticomán, México DF 07340 (Mexico); Contreras, Rosalinda [Departamento de Química, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México DF 07000 (Mexico); Barrio La Laguna Ticomán, México DF 07340 (Mexico); Pineda-Urbina, Kayim; Ramos-Organillo, Angel, E-mail: aaramos@ucol.mx [Facultad de Ciencias Químicas, Universidad de Colima, Carretera Coquimatlán-Colima, Coquimatlán Colima 28400 (Mexico)

    2015-08-12

    In two trimethylsilyl-substituted 1H-benzimidazole-2(3H)-thiones, noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe{sub 3} groups form helicoidal arrangements in one, and dimerization results in the formation of R{sub s} {sup 2}(8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings, in the second compound. Two new molecular structures, namely 1,3-bis(trimethylsilyl)-1H-benzimidazole-2(3H)-thione, C{sub 13}H{sub 22}N{sub 2}SSi{sub 2}, (2), and 1-trimethylsilyl-1H-benzimidazole-2(3H)-thione, C{sub 10}H{sub 14}N{sub 2}SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe{sub 3} groups form helicoidal arrangements in (2). Dimerization of (3) results in the formation of R{sub 2}{sup 2}(8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings.

  18. Diagnostic value of C-peptide determination

    International Nuclear Information System (INIS)

    Kober, G.; Rainer, O.H.

    1983-01-01

    C-peptide and insulin serum determinations were performed in 94 glucagon-stimulated diabetics and in 15 healthy persons. A minimal increase of 1.5 ng C-peptide/ml serum after glucagon injection (1 mg i.v.) was found to be a useful parameter for the differentiation of insulin dependent and non-insulin dependent diabetics. The maximal response to glucagon occurred during the first 10-minutes after the injection (blood was drawn at 2-minutes intervals). Serum insulin levels and basal C-peptide concentrations were of no value in predicting insulin-dependency. Basal C-peptide levels were significantly different from control in juvenile insulin dependent diabetics (decrease) only. (Author)

  19. Identification of the peptide derived from S1 domain that inhibits type I and type II feline infectious peritonitis virus infection.

    Science.gov (United States)

    Doki, Tomoyoshi; Takano, Tomomi; Koyama, Yusuke; Hohdatsu, Tsutomu

    2015-06-02

    Feline infectious peritonitis virus (FIPV) can cause a lethal disease in cats, feline infectious peritonitis (FIP). A therapeutic drug that is effective against FIP has not yet been developed. Peptides based on viral protein amino acid sequences have recently been attracting attention as new antiviral drugs. In the present study, we synthesized 30 overlapping peptides based on the amino acid sequence of the S1 domain of the type I FIPV strain KU-2 S protein, and investigated their inhibitory effects on FIPV infection. To evaluate the inhibitory effects on type I FIPV infection of these peptides, we investigated a method to increase the infection efficiency of poorly replicative type I FIPV. The efficiency of type I FIPV infection was increased by diluting the virus with medium containing a polycation. Of the 30 peptides, I-S1-8 (S461-S480), I-S1-9 (S471-S490), I-S1-10 (S481-S500), I-S1-16 (S541-S560), and I-S1-22 (S601-S620) significantly decreased the infectivity of FIPV strain KU-2 while I-S1-9 and I-S1-16 exhibited marked inhibitory effects on FIPV infection. The inhibitory effects on FIPV infection of these 2 peptides on other type I and type II FIPV strains, feline herpesvirus (FHV), and feline calicivirus (FCV) were also examined. These 2 peptides specifically inhibited type I and type II FIPV, but did FHV or FCV infection. In conclusion, the possibility of peptides derived from the S protein of type I FIPV strain KU-2 as anti-FIPV agents effective not only for type I, but also type II FIPV was demonstrated in vitro. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Solution Structure of LXXLL-related Cofactor Peptide of Orphan Nuclear Receptor FTZ-F1

    International Nuclear Information System (INIS)

    Yun, Ji Hye; Lee, Chul Jin; Jung, Jin Won; Lee, Weon Tae

    2012-01-01

    Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide (FTZ PEP ) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, FTZ PEP formed α- helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of FTZ PEP . The solution structure of FTZ PEP in the presence of FTZ-F1 displays a long stretch of the α-helix with a bend in the middle of helix

  1. Solution Structure of LXXLL-related Cofactor Peptide of Orphan Nuclear Receptor FTZ-F1

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ji Hye; Lee, Chul Jin; Jung, Jin Won; Lee, Weon Tae [Yonsei University, Seoul (Korea, Republic of)

    2012-02-15

    Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide (FTZ{sup PEP}) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, FTZ{sup PEP} formed α- helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of FTZ{sup PEP}. The solution structure of FTZ{sup PEP} in the presence of FTZ-F1 displays a long stretch of the α-helix with a bend in the middle of helix.

  2. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  3. Destabilization of Human Insulin Fibrils by Peptides of Fruit Bromelain Derived From Ananas comosus (Pineapple).

    Science.gov (United States)

    Das, Sromona; Bhattacharyya, Debasish

    2017-12-01

    Deposition of insulin aggregates in human body leads to dysfunctioning of several organs. Effectiveness of fruit bromelain from pineapple in prevention of insulin aggregate was investigated. Proteolyses of bromelain was done as par human digestive system and the pool of small peptides was separated from larger peptides and proteins. Under conditions of growth of insulin aggregates from its monomers, this pool of peptides restricted the reaction upto formation of oligomers of limited size. These peptides also destabilized preformed insulin aggregates to oligomers. These processes were followed fluorimetrically using Thioflavin T and 1-ANS, size-exclusion HPLC, dynamic light scattering, atomic force microscopy, and transmission electron microscopy. Sequences of insulin (A and B chains) and bromelain were aligned using Clustal W software to predict most probable sites of interactions. Synthetic tripeptides corresponding to the hydrophobic interactive sites of bromelain showed disaggregation of insulin suggesting specificity of interactions. The peptides GG and AAA serving as negative controls showed no potency in destabilization of aggregates. Disaggregation potency of the peptides was also observed when insulin was deposited on HepG2 liver cells where no formation of toxic oligomers occurred. Amyloidogenic des-octapeptide (B23-B30 of insulin) incapable of cell signaling showed cytotoxicity similar to insulin. This toxicity could be neutralized by bromelain derived peptides. FT-IR and far-UV circular dichroism analysis indicated that disaggregated insulin had structure distinctly different from that of its hexameric (native) or monomeric states. Based on the stoichiometry of interaction and irreversibility of disaggregation, the mechanism/s of the peptides and insulin interactions has been proposed. J. Cell. Biochem. 118: 4881-4896, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. A mucin-like peptide from Fasciola hepatica induces parasite-specific Th1-type cell immunity.

    Science.gov (United States)

    Noya, Verónica; Brossard, Natalie; Berasaín, Patricia; Rodríguez, Ernesto; Chiale, Carolina; Mazal, Daniel; Carmona, Carlos; Freire, Teresa

    2016-03-01

    Fasciolosis, caused by the liver fluke Fasciola hepatica, is a major parasitic disease of livestock that causes significant economic losses worldwide. Although drugs are effective against liver flukes, they do not prevent reinfection, and continuous treatment is costly. Moreover, resistant fluke strains are emerging. In this context, vaccination is a good alternative since it provides a cost-effective long-term prevention strategy to control fasciolosis. In this paper, we evaluate the Fhmuc peptide as a potential vaccine against fasciolosis. This peptide derives from a mucin-like protein highly expressed in the infective stage of Fasciola hepatica. Mucin-like molecules expressed by parasites can contribute to several infection processes by protecting the parasite from host proteases and recognition by the immune system. We show that the Fhmuc peptide induces Th1-like immune responses specific for F. hepatica excretion-secretion products (FhESP) with a high production of IFNγ. We also investigated whether this peptide could protect animals from infection, and present preliminary data indicating that animals treated with Fhmuc exhibited reduced liver damage compared to non-immunised animals and that this protection was associated with a recruitment of B and T lymphocytes in the peritoneum, as well as eosinophils and mature dendritic cells. These results suggest that the mucin-like peptide Fhmuc could constitute a potential vaccine candidate against fasciolosis and pave the way towards the development of vaccines against parasites.

  5. Expression of the cationic antimicrobial peptide lactoferricin fused with the anionic peptide in Escherichia coli.

    Science.gov (United States)

    Kim, Ha-Kun; Chun, Dae-Sik; Kim, Joon-Sik; Yun, Cheol-Ho; Lee, Ju-Hoon; Hong, Soon-Kwang; Kang, Dae-Kyung

    2006-09-01

    Direct expression of lactoferricin, an antimicrobial peptide, is lethal to Escherichia coli. For the efficient production of lactoferricin in E. coli, we developed an expression system in which the gene for the lysine- and arginine-rich cationic lactoferricin was fused to an anionic peptide gene to neutralize the basic property of lactoferricin, and successfully overexpressed the concatemeric fusion gene in E. coli. The lactoferricin gene was linked to a modified magainin intervening sequence gene by a recombinational polymerase chain reaction, thus producing an acidic peptide-lactoferricin fusion gene. The monomeric acidic peptide-lactoferricin fusion gene was multimerized and expressed in E. coli BL21(DE3) upon induction with isopropyl-beta-D-thiogalactopyranoside. The expression levels of the fusion peptide reached the maximum at the tetramer, while further increases in the copy number of the fusion gene substantially reduced the peptide expression level. The fusion peptides were isolated and cleaved to generate the separate lactoferricin and acidic peptide. About 60 mg of pure recombinant lactoferricin was obtained from 1 L of E. coli culture. The purified recombinant lactoferricin was found to have a molecular weight similar to that of chemically synthesized lactoferricin. The recombinant lactoferricin showed antimicrobial activity and disrupted bacterial membrane permeability, as the native lactoferricin peptide does.

  6. Specific expression of GFPuv-β1,3-N-acetylglucosaminyltransferase 2 fusion protein in fat body of Bombyx mori silkworm larvae using signal peptide

    International Nuclear Information System (INIS)

    Kato, Tatsuya; Park, Enoch Y.

    2007-01-01

    Bombyxin (bx) and prophenoloxidase-activating enzyme (ppae) signal peptides from Bombyx mori, their modified signal peptides, and synthetic signal peptides were investigated for the secretion of GFP uv -β1,3-N-acetylglucosaminyltransferase 2 (GGT2) fusion protein in B. mori Bm5 cells and silkworm larvae using cysteine protease deficient B. mori multiple nucleopolyhedrovirus (BmMNPV-CP - ) and its bacmid. The secretion efficiencies of all signal peptides were 15-30% in Bm5 cells and 24-30% in silkworm larvae, while that of the +16 signal peptide was 0% in Bm5 cells and 1% in silkworm larvae. The fusion protein that contained the +16 signal peptide was expressed specifically in the endoplasmic reticulum (ER) and in the fractions of cell precipitations. Ninety-four percent of total intracellular β1,3-N-acetylglucosaminyltransferase (β3GnT) activity was detected in cell precipitations following the 600, 8000, and 114,000g centrifugations. In the case of the +38 signal peptide, 60% of total intracellular activity was detected in the supernatant from the 114,000g spin, and only 1% was found in the precipitate. Our results suggest that the +16 signal peptide might be situated in the transmembrane region and not cleaved by signal peptidase in silkworm or B. mori cells. Therefore, the fusion protein connected to the +16 signal peptide stayed in the fat body of silkworm larvae with biological function, and was not secreted extracellularly

  7. Cyclic peptide inhibitors of lysine-specific demethylase 1 with improved potency identified by alanine scanning mutagenesis.

    Science.gov (United States)

    Kumarasinghe, Isuru R; Woster, Patrick M

    2018-03-25

    Lysine-specific demethylase 1 (LSD1) is a chromatin-remodeling enzyme that plays an important role in cancer. Over-expression of LSD1 decreases methylation at histone 3 lysine 4, and aberrantly silences tumor suppressor genes. Inhibitors of LSD1 have been designed as chemical probes and potential antitumor agents. We recently reported the cyclic peptide 9, which potently and reversibly inhibits LSD1 (IC 50 2.1 μM; K i 385 nM). Systematic alanine mutagenesis of 9 revealed residues that are critical for LSD1 inhibition, and these mutated peptides were evaluated as LSD1 inhibitors. Alanine substitution at positions 2, 3, 4, 6 and 11-17 preserved inhibition, while substitution of alanine at positions 8 and 9 resulted in complete loss of activity. Cyclic mutant peptides 11 and 16 produced the greatest LSD1 inhibition, and 11, 16, 27 and 28 increased global H3K4me2 in K562 cells. In addition, 16, 27 and 28 promoted significant increases in H3K4me2 levels at the promoter sites of the genes IGFBP2 and FEZ1. Data from these LSD1 inhibitors will aid in the design of peptidomimetics with improved stability and pharmacokinetics. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  8. Identification of the bacteria-binding peptide domain on salivary agglutinin (gp-340/DMBT1), a member of the scavenger receptor cysteine-rich superfamily

    DEFF Research Database (Denmark)

    Bikker, Floris J; Ligtenberg, Antoon J M; Nazmi, Kamran

    2002-01-01

    Salivary agglutinin is encoded by DMBT1 and identical to gp-340, a member of the scavenger receptor cysteine-rich (SRCR) superfamily. Salivary agglutinin/DMBT1 is known for its Streptococcus mutans agglutinating properties. This 300-400 kDa glycoprotein is composed of conserved peptide motifs: 14...... containing exclusively SRCR and SID domains that binds to S. mutans. To define more closely the S. mutans-binding domain, consensus-based peptides of the SRCR domains and SIDs were designed and synthesized. Only one of the SRCR peptides, designated SRCRP2, and none of the SID peptides bound to S. mutans....... Strikingly, this peptide was also able to induce agglutination of S. mutans and a number of other bacteria. The repeated presence of this peptide in the native molecule endows agglutinin/DMBT1 with a general bacterial binding feature with a multivalent character. Moreover, our studies demonstrate...

  9. Improved methods for predicting peptide binding affinity to MHC class II molecules.

    Science.gov (United States)

    Jensen, Kamilla Kjaergaard; Andreatta, Massimo; Marcatili, Paolo; Buus, Søren; Greenbaum, Jason A; Yan, Zhen; Sette, Alessandro; Peters, Bjoern; Nielsen, Morten

    2018-01-06

    Major histocompatibility complex class II (MHC-II) molecules are expressed on the surface of professional antigen-presenting cells where they display peptides to T helper cells, which orchestrate the onset and outcome of many host immune responses. Understanding which peptides will be presented by the MHC-II molecule is therefore important for understanding the activation of T helper cells and can be used to identify T-cell epitopes. We here present updated versions of two MHC-II-peptide binding affinity prediction methods, NetMHCII and NetMHCIIpan. These were constructed using an extended data set of quantitative MHC-peptide binding affinity data obtained from the Immune Epitope Database covering HLA-DR, HLA-DQ, HLA-DP and H-2 mouse molecules. We show that training with this extended data set improved the performance for peptide binding predictions for both methods. Both methods are publicly available at www.cbs.dtu.dk/services/NetMHCII-2.3 and www.cbs.dtu.dk/services/NetMHCIIpan-3.2. © 2018 John Wiley & Sons Ltd.

  10. Peptide transport through the blood-brain barrier. Final report 1 Jul 87-31 Dec 90

    Energy Technology Data Exchange (ETDEWEB)

    Partridge, W.M.

    1991-01-15

    Most neuropeptides are incapable of entering the brain from blood owing to the presence of unique anatomical structures in the brain capillary wall, which makes up the blood-brain barrier (BBB). Such neuropeptides could be introduced into the bloodstream by intranasal insufflation and, thus, could have powerful medicinal properties (e.g., Beta-endorphin for the treatment of pain, vasopressin analogues for treatment of memory, ACTH analogues for treatment of post-traumatic epilepsy), should these peptides be capable of traversing the BBB. One such strategy for peptide delivery through the BBB is the development of chimeric peptides, which is the basis of the present contract. The production of chimeric peptides involves the covalent coupling of a nontransportable peptide (e.g., Beta-endorphin, vasopressin) to a transportable vector peptide (e.g., insulin, transferrin, cationized albumin, histone). The transportable peptide is capable of penetrating the BBB via receptor-mediated or absorptive-mediated transcytosis. Therefore, the introduction of chimeric peptides allows the nontransportable peptide to traverse the BBB via a physiologic piggy back mechanism.

  11. Milk peptides increase iron solubility in water but do not affect DMT-1 expression in Caco-2 cells

    Science.gov (United States)

    In vitro digestion of milk produces peptide fractions that enhance iron uptake by Caco-2 cells. Our objectives were to investigate whether these fractions a) exert their effect by increasing relative gene expression of DMT-1 in Caco-2 cells b) enhance iron dialyzability when added in meals. Peptid...

  12. T cells reactive with HLA-A*0201 peptides from the histone demethylase JARID1B are found in the circulation of breast cancer patients.

    Science.gov (United States)

    Coleman, Julia A; Correa, Isabel; Cooper, Lucienne; Bohnenkamp, Hermann R; Poulsom, Richard; Burchell, Joy M; Taylor-Papadimitriou, Joyce

    2011-05-01

    The nuclear protein PLU-1/JARID1B/KDM5 is widely expressed in breast cancers while showing highly restricted expression in normal adult tissues. To investigate whether JARID1B is a potential target antigen for immunotherapy of breast cancer, we have analyzed the responses of CD8(+) T cells to JARID1B HLA-A*0201 peptides in vitro and used peptide multimers to detect the presence of JARID1B reactive T cells in the circulation of breast cancer patients. Peptides were selected using two web-based algorithms: criteria for inclusion being a high score in both prediction algorithms, and nonhomology with retinoblastoma binding protein-2 (RBP2/JARID1A/KDM5A). A 65-peptide panel was selected and assayed for binding strength by competition assay to obtain the IC(50). The immunogenicity in vitro of these peptides was assessed by T cell stimulation experiments, using autologous dendritic cells as APCs in the first rounds followed by autologous lymphoblasts. Fourteen of the peptides assayed produced cultures having >2% of the CD8(+) cells being IFN-γ(+) after 3-6 rounds of stimulation. An HLA-A*0201 cell line could activate the specific T cells if pulsed with peptide, but endogenous peptide levels were insufficient for activation. Nevertheless, multimer staining of circulating T cells from breast cancer patients showed a significantly higher percentage of multimer positive CD8(+) T cells, as compared to healthy adults for two of three JARID1B epitopes tested. One of these, peptide 73 (QLYALPCVL), was analyzed for memory phenotype, and found to have a significantly higher proportion of central memory T cells than the control group, demonstrating a previous exposure to the peptide. Copyright © 2011 UICC.

  13. Short-term glucagon stimulation test of C-peptide effect on glucose utilization in patients with type 1 diabetes mellitus.

    Science.gov (United States)

    Mojto, Viliam; Rausova, Zuzana; Chrenova, Jana; Dedik, Ladislav

    2015-12-01

    This work aimed to evaluate the use of a four-point glucagon stimulation test of C-peptide effect on glucose utilization in type 1 diabetic patients using a new mathematical model. A group of 32 type 1 diabetic patients and a group of 10 healthy control subjects underwent a four-point glucagon stimulation test with blood sampling at 0, 6, 15 and 30 min after 1 mg glucagon bolus intravenous administration. Pharmacokinetic and pharmacokinetic/pharmacodynamic models of C-peptide effect on glucose utilization versus area under curve (AUC) were used. A two-sample t test and ANOVA with Bonferroni correction were used to test the significance of differences between parameters. A significant difference between control and patient groups regarding the coefficient of whole-body glucose utilization and AUC C-peptide/AUC glucose ratio (p ≪ 0.001 and p = 0.002, respectively) was observed. The high correlation (r = 0.97) between modeled coefficient of whole-body glucose utilization and numerically calculated AUC C-peptide/AUC glucose ratio related to entire cohort indicated the stability of used method. The short-term four-point glucagon stimulation test allows the numerically calculated AUC C-peptide/AUC glucose ratio and/or the coefficient of whole-body glucose utilization calculated from model to be used to diagnostically identify type 1 diabetic patients.

  14. Antibody constant region peptides can display immunomodulatory activity through activation of the Dectin-1 signalling pathway.

    Directory of Open Access Journals (Sweden)

    Elena Gabrielli

    Full Text Available We previously reported that a synthetic peptide with sequence identical to a CDR of a mouse monoclonal antibody specific for difucosyl human blood group A exerted an immunomodulatory activity on murine macrophages. It was therapeutic against systemic candidiasis without possessing direct candidacidal properties. Here we demonstrate that a selected peptide, N10K, putatively deriving from the enzymatic cleavage of the constant region (Fc of human IgG(1, is able to induce IL-6 secretion and pIkB-α activation. More importantly, it causes an up-regulation of Dectin-1 expression. This leads to an increased activation of β-glucan-induced pSyk, CARD9 and pIkB-α, and an increase in the production of pro-inflammatory cytokines such as IL-6, IL-12, IL-1β and TNF-α. The increased activation of this pathway coincides with an augmented phagocytosis of non opsonized Candida albicans cells by monocytes. The findings suggest that some Fc-peptides, potentially deriving from the proteolysis of immunoglobulins, may cause an unexpected immunoregulation in a way reminiscent of innate immunity molecules.

  15. Phase 1 clinical study of cyclophilin B peptide vaccine for patients with lung cancer.

    Science.gov (United States)

    Gohara, Rumi; Imai, Nobue; Rikimaru, Toru; Yamada, Akira; Hida, Naoya; Ichiki, Masao; Kawamoto, Mayumi; Matsunaga, Kazuko; Ashihara, Junko; Yano, Sayoko; Tamura, Mayumi; Ohkouchi, Shinya; Yamana, Hideaki; Oizumi, Kotaro; Itoh, Kyogo

    2002-01-01

    Cyclophilin B (CypB) possesses two antigenic epitopes (CypB(84-92) and CypB(91-99) ) recognized by HLA-A24-restricted and tumor-specific cytotoxic T lymphocytes (CTLs). To determine the safety of CypB-derived peptides and its ability to generate antitumor immune responses, patients with advanced lung cancer received subcutaneous vaccinations of these peptides or their modified peptides. All 16 patients were vaccinated with CypB(91-99) or its modified peptide, whereas only two patients were vaccinated with the modified CypB(84-92), as immediate-type hypersensitivity to CypB(84-92) or its modified peptide was observed in the remaining patients. No severe adverse events were associated with the vaccination. No significant increase in cellular responses to either peptides or tumor cells was observed in the postvaccination PBMCs by the conventional CTL assays in any patients tested. These results suggest that the vaccination of CypB(91-99) peptide was safe, but failed to induce objective immune responses at this regimen.

  16. Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins

    Directory of Open Access Journals (Sweden)

    Marwa Yousr

    2015-12-01

    Full Text Available Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF. Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y and tryptophan (W, in sequences identified by LC-MS as WYGPD (EYGF-23 and KLSDW (EYGF-33, contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56 was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69% and IC50 value (3.35 mg/mL. The SDNRNQGY peptide (10 mg/mL had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL. In addition, YPSPV in (EYGF-33 (10 mg/mL had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

  17. Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins.

    Science.gov (United States)

    Yousr, Marwa; Howell, Nazlin

    2015-12-07

    Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

  18. Non-invasive glucagon-like peptide-1 receptor imaging in pancreas with {sup 18}F-Al labeled Cys{sup 39}-exendin-4

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Baoming [Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006 (China); Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University (Wuxi 4th People' s Hospital), Wuxi, Jiangsu, 214062 (China); Xu, Yuping [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Nanjing Medical University, Nanjing, Jiangsu, 210029 (China); Pan, Donghui; Wang, Lizhen; Yang, Runlin [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Yu, Chunjing; Wan, Weixing [Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University (Wuxi 4th People' s Hospital), Wuxi, Jiangsu, 214062 (China); Wu, Yiwei, E-mail: wuyiwei3988@gmail.com [Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006 (China); Yang, Min, E-mail: ymzfk@yahoo.com.hk [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Nanjing Medical University, Nanjing, Jiangsu, 210029 (China)

    2016-02-26

    Purpose: Glucagon-like peptide-1 receptor (GLP-1R) is abundantly expressed on beta cells and may be an ideal target for the pancreas imaging. Monitoring the GLP-1R of pancreas could be benefit for understanding the pathophysiology of diabetes. In the present study, {sup 18}F-Al labeled exendin-4 analog, {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4, was evaluated for PET imaging GLP-1R in the pancreas. Methods: The targeting of {sup 18}F-Al labeled exendin-4 analog was examined in healthy and streptozotocin induced diabetic rats. Rats were injected with {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4 and microPET imaging was performed at 1 h postinjection, followed by ex vivo biodistribution. GLP-1R expression in pancreas was determined through post mortern examinations. Results: The pancreas of healthy rats was readily visualized after administration of {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4, whereas the pancreas of diabetic rats, as well as those from rats co-injected with excess of unlabeled peptides, was barely visible by microPET. At 60 min postinjection, the pancreatic uptakes were 1.02 ± 0.15%ID/g and 0.23 ± 0.05%ID/g in healthy and diabetic rats respectively. Under block, the pancreatic uptakes of non-diabetic rats reduced to 0.21 ± 0.07%ID/g at the same time point. Biodistribution data and IHC staining confirmed the findings of the microPET imaging. Conclusion: The favorable preclinical data indicated that {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4may be suitable for non-invasive monitoring functional pancreatic beta cells.

  19. Disulfide Bridges: Bringing Together Frustrated Structure in a Bioactive Peptide.

    Science.gov (United States)

    Zhang, Yi; Schulten, Klaus; Gruebele, Martin; Bansal, Paramjit S; Wilson, David; Daly, Norelle L

    2016-04-26

    Disulfide bridges are commonly found covalent bonds that are usually believed to maintain structural stability of proteins. Here, we investigate the influence of disulfide bridges on protein dynamics through molecular dynamics simulations on the cysteine-rich trypsin inhibitor MCoTI-II with three disulfide bridges. Correlation analysis of the reduced cyclic peptide shows that two of the three disulfide distances (Cys(11)-Cys(23) and Cys(17)-Cys(29)) are anticorrelated within ∼1 μs of bridge formation or dissolution: when the peptide is in nativelike structures and one of the distances shortens to allow bond formation, the other tends to lengthen. Simulations over longer timescales, when the denatured state is less structured, do not show the anticorrelation. We propose that the native state contains structural elements that frustrate one another's folding, and that the two bridges are critical for snapping the frustrated native structure into place. In contrast, the Cys(4)-Cys(21) bridge is predicted to form together with either of the other two bridges. Indeed, experimental chromatography and nuclear magnetic resonance data show that an engineered peptide with the Cys(4)-Cys(21) bridge deleted can still fold into its near-native structure even in its noncyclic form, confirming the lesser role of the Cys(4)-Cys(21) bridge. The results highlight the importance of disulfide bridges in a small bioactive peptide to bring together frustrated structure in addition to maintaining protein structural stability. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Pentastatin-1, a collagen IV derived 20-mer peptide, suppresses tumor growth in a small cell lung cancer xenograft model.

    Science.gov (United States)

    Koskimaki, Jacob E; Karagiannis, Emmanouil D; Tang, Benjamin C; Hammers, Hans; Watkins, D Neil; Pili, Roberto; Popel, Aleksander S

    2010-02-01

    Angiogenesis is the formation of neovasculature from a pre-existing vascular network. Progression of solid tumors including lung cancer is angiogenesis-dependent. We previously introduced a bioinformatics-based methodology to identify endogenous anti-angiogenic peptide sequences, and validated these predictions in vitro in human umbilical vein endothelial cell (HUVEC) proliferation and migration assays. One family of peptides with high activity is derived from the alpha-fibrils of type IV collagen. Based on the results from the in vitro screening, we have evaluated the ability of a 20 amino acid peptide derived from the alpha5 fibril of type IV collagen, pentastatin-1, to suppress vessel growth in an angioreactor-based directed in vivo angiogenesis assay (DIVAA). In addition, pentastatin-1 suppressed tumor growth with intraperitoneal peptide administration in a small cell lung cancer (SCLC) xenograft model in nude mice using the NCI-H82 human cancer cell line. Pentastatin-1 decreased the invasion of vessels into angioreactors in vivo in a dose dependent manner. The peptide also decreased the rate of tumor growth and microvascular density in vivo in a small cell lung cancer xenograft model. The peptide treatment significantly decreased the invasion of microvessels in angioreactors and the rate of tumor growth in the xenograft model, indicating potential treatment for angiogenesis-dependent disease, and for translational development as a therapeutic agent for lung cancer.

  1. Pentastatin-1, a collagen IV derived 20-mer peptide, suppresses tumor growth in a small cell lung cancer xenograft model

    International Nuclear Information System (INIS)

    Koskimaki, Jacob E; Karagiannis, Emmanouil D; Tang, Benjamin C; Hammers, Hans; Watkins, D Neil; Pili, Roberto; Popel, Aleksander S

    2010-01-01

    Angiogenesis is the formation of neovasculature from a pre-existing vascular network. Progression of solid tumors including lung cancer is angiogenesis-dependent. We previously introduced a bioinformatics-based methodology to identify endogenous anti-angiogenic peptide sequences, and validated these predictions in vitro in human umbilical vein endothelial cell (HUVEC) proliferation and migration assays. One family of peptides with high activity is derived from the α-fibrils of type IV collagen. Based on the results from the in vitro screening, we have evaluated the ability of a 20 amino acid peptide derived from the α5 fibril of type IV collagen, pentastatin-1, to suppress vessel growth in an angioreactor-based directed in vivo angiogenesis assay (DIVAA). In addition, pentastatin-1 suppressed tumor growth with intraperitoneal peptide administration in a small cell lung cancer (SCLC) xenograft model in nude mice using the NCI-H82 human cancer cell line. Pentastatin-1 decreased the invasion of vessels into angioreactors in vivo in a dose dependent manner. The peptide also decreased the rate of tumor growth and microvascular density in vivo in a small cell lung cancer xenograft model. The peptide treatment significantly decreased the invasion of microvessels in angioreactors and the rate of tumor growth in the xenograft model, indicating potential treatment for angiogenesis-dependent disease, and for translational development as a therapeutic agent for lung cancer

  2. Purification, characterization, and sequencing of novel antimicrobial peptides, Tu-AMP 1 and Tu-AMP 2, from bulbs of tulip (Tulipa gesneriana L.).

    Science.gov (United States)

    Fujimura, Masatoshi; Ideguchi, Mineo; Minami, Yuji; Watanabe, Keiichi; Tadera, Kenjiro

    2004-03-01

    Novel antimicrobial peptides (AMP), designated Tu-AMP 1 and Tu-AMP 2, were purified from the bulbs of tulip (Tulipa gesneriana L.) by chitin affinity chromatography and reverse-phase high-performance liquid chromatography (HPLC). They bind to chitin in a reversible way. They were basic peptides having isoelectric points of over 12. Tu-AMP 1 and Tu-AMP 2 had molecular masses of 4,988 Da and 5,006 Da on MALDI-TOF MS analysis, and their extinction coefficients of 1% aqueous solutions at 280 nm were 3.3 and 3.4, respectively. Half of all amino acid residues of Tu-AMP 1 and Tu-AMP 2 were occupied by cysteine, arginine, lysine, and proline. The concentrations of peptides required for 50% inhibition (IC(50)) of the growth of plant pathogenic bacteria and fungi were 2 to 20 microg/ml. The structural characteristics of Tu-AMP 1 and Tu-AMP 2 indicated that they were novel thionin-like antimicrobial peptides, though Tu-AMP 2 was a heterodimer composes of two short peptides joined with disulfide bonds.

  3. Fixed ratio combinations of glucagon like peptide 1 receptor agonists with basal insulin: a systematic review and meta-analysis.

    Science.gov (United States)

    Liakopoulou, Paraskevi; Liakos, Aris; Vasilakou, Despoina; Athanasiadou, Eleni; Bekiari, Eleni; Kazakos, Kyriakos; Tsapas, Apostolos

    2017-06-01

    Basal insulin controls primarily fasting plasma glucose but causes hypoglycaemia and weight gain, whilst glucagon like peptide 1 receptor agonists induce weight loss without increasing risk for hypoglycaemia. We conducted a systematic review and meta-analysis of randomised controlled trials to investigate the efficacy and safety of fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists. We searched Medline, Embase, and the Cochrane Library as well as conference abstracts up to December 2016. We assessed change in haemoglobin A 1c , body weight, and incidence of hypoglycaemia and gastrointestinal adverse events. We included eight studies with 5732 participants in the systematic review. Switch from basal insulin to fixed ratio combinations with a glucagon like peptide 1 receptor agonist was associated with 0.72% reduction in haemoglobin A 1c [95% confidence interval -1.03 to -0.41; I 2  = 93%] and 2.35 kg reduction in body weight (95% confidence interval -3.52 to -1.19; I 2  = 93%), reducing also risk for hypoglycaemia [odds ratio 0.70; 95% confidence interval 0.57 to 0.86; I 2  = 85%] but increasing incidence of nausea (odds ratio 6.89; 95% confidence interval 3.73-12.74; I 2  = 79%). Similarly, switching patients from treatment with a glucagon like peptide 1 receptor agonist to a fixed ratio combination with basal insulin was associated with 0.94% reduction in haemoglobin A 1c (95% confidence interval -1.11 to -0.77) and an increase in body weight by 2.89 kg (95% confidence interval 2.17-3.61). Fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists improve glycaemic control whilst balancing out risk for hypoglycaemia and gastrointestinal side effects.

  4. A cocoa peptide protects Caenorhabditis elegans from oxidative stress and β-amyloid peptide toxicity.

    Directory of Open Access Journals (Sweden)

    Patricia Martorell

    Full Text Available BACKGROUND: Cocoa and cocoa-based products contain different compounds with beneficial properties for human health. Polyphenols are the most frequently studied, and display antioxidant properties. Moreover, protein content is a very interesting source of antioxidant bioactive peptides, which can be used therapeutically for the prevention of age-related diseases. METHODOLOGY/PRINCIPAL FINDINGS: A bioactive peptide, 13L (DNYDNSAGKWWVT, was obtained from a hydrolyzed cocoa by-product by chromatography. The in vitro inhibition of prolyl endopeptidase (PEP was used as screening method to select the suitable fraction for peptide identification. Functional analysis of 13L peptide was achieved using the transgenic Caenorhabditis elegans strain CL4176 expressing the human Aβ₁₋₄₂ peptide as a pre-clinical in vivo model for Alzheimer's disease. Among the peptides isolated, peptide 13L (1 µg/mL showed the highest antioxidant activity (P≤0.001 in the wild-type strain (N2. Furthermore, 13L produced a significant delay in body paralysis in strain CL4176, especially in the 24-47 h period after Aβ₁₋₄₂ peptide induction (P≤0.0001. This observation is in accordance with the reduction of Aβ deposits in CL4176 by western blot. Finally, transcriptomic analysis in wild-type nematodes treated with 13L revealed modulation of the proteosomal and synaptic functions as the main metabolic targets of the peptide. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the cocoa 13L peptide has antioxidant activity and may reduce Aβ deposition in a C. elegans model of Alzheimer's disease; and therefore has a putative therapeutic potential for prevention of age-related diseases. Further studies in murine models and humans will be essential to analyze the effectiveness of the 13L peptide in higher animals.

  5. Characterization of an insulin-like growth factor-I/somatomedin-C radioimmunoassay specific for the C-peptide region

    International Nuclear Information System (INIS)

    Hintz, R.L.; Liu, F.; Seegan, G.

    1982-01-01

    Insulin-like growth factor-I (IGF-I) and somatomedin-C (SM-C) have been shown to be functionally identical by a number of criteria. We have synthesized the 12 amino acid C-peptide region of IGF-I (Gly-Tyr-Gly-Ser-Ser-Ser-Arg-Arg-Ala-Pro-Glu-Thr) and developed a RIA based on antibodies against this synthetic peptide. IGF-I and SM-C were indistinguishable in this RIA. No other peptides competed for this antiserum. The SM-C/IGF-I values of acid-chromatographed serum were strongly age dependent. The mean of children 1-5 yr old was 0.67 +/- 0.033 U/ml (mean +/- sD; n = 23), whereas the mean of children 12-17 yr old was 2.01 +/- 0.66 U/ml (n = 39) and the mean of 38 adults 26-85 yr old was 1.05 +/- 0.34. The SM-C/IGF-I values measured by this RIA were also growth hormone dependent. Thus, this region-specific RIA provides a clinically useful assessment of serum SM-C/IGF-I levels

  6. Multifunctional hybrid networks based on self assembling peptide sequences

    Science.gov (United States)

    Sathaye, Sameer

    The overall aim of this dissertation is to achieve a comprehensive correlation between the molecular level changes in primary amino acid sequences of amphiphilic beta-hairpin peptides and their consequent solution-assembly properties and bulk network hydrogel behavior. This has been accomplished using two broad approaches. In the first approach, amino acid substitutions were made to peptide sequence MAX1 such that the hydrophobic surfaces of the folded beta-hairpins from the peptides demonstrate shape specificity in hydrophobic interactions with other beta-hairpins during the assembly process, thereby causing changes to the peptide nanostructure and bulk rheological properties of hydrogels formed from the peptides. Steric lock and key complementary hydrophobic interactions were designed to occur between two beta-hairpin molecules of a single molecule, LNK1 during beta-sheet fibrillar assembly of LNK1. Experimental results from circular dichroism, transmission electron microscopy and oscillatory rheology collectively indicate that the molecular design of the LNK1 peptide can be assigned the cause of the drastically different behavior of the networks relative to MAX1. The results indicate elimination or significant reduction of fibrillar branching due to steric complementarity in LNK1 that does not exist in MAX1, thus supporting the original hypothesis. As an extension of the designed steric lock and key complementarity between two beta-hairpin molecules of the same peptide molecule. LNK1, three new pairs of peptide molecules LP1-KP1, LP2-KP2 and LP3-KP3 that resemble complementary 'wedge' and 'trough' shapes when folded into beta-hairpins were designed and studied. All six peptides individually and when blended with their corresponding shape complement formed fibrillar nanostructures with non-uniform thickness values. Loose packing in the assembled structures was observed in all the new peptides as compared to the uniform tight packing in MAX1 by SANS analysis. This

  7. Bromine isotopic signature facilitates de novo sequencing of peptides in free-radical-initiated peptide sequencing (FRIPS) mass spectrometry.

    Science.gov (United States)

    Nam, Jungjoo; Kwon, Hyuksu; Jang, Inae; Jeon, Aeran; Moon, Jingyu; Lee, Sun Young; Kang, Dukjin; Han, Sang Yun; Moon, Bongjin; Oh, Han Bin

    2015-02-01

    We recently showed that free-radical-initiated peptide sequencing mass spectrometry (FRIPS MS) assisted by the remarkable thermochemical stability of (2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) is another attractive radical-driven peptide fragmentation MS tool. Facile homolytic cleavage of the bond between the benzylic carbon and the oxygen of the TEMPO moiety in o-TEMPO-Bz-C(O)-peptide and the high reactivity of the benzylic radical species generated in •Bz-C(O)-peptide are key elements leading to extensive radical-driven peptide backbone fragmentation. In the present study, we demonstrate that the incorporation of bromine into the benzene ring, i.e. o-TEMPO-Bz(Br)-C(O)-peptide, allows unambiguous distinction of the N-terminal peptide fragments from the C-terminal fragments through the unique bromine doublet isotopic signature. Furthermore, bromine substitution does not alter the overall radical-driven peptide backbone dissociation pathways of o-TEMPO-Bz-C(O)-peptide. From a practical perspective, the presence of the bromine isotopic signature in the N-terminal peptide fragments in TEMPO-assisted FRIPS MS represents a useful and cost-effective opportunity for de novo peptide sequencing. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Peptide aptamers as new tools to modulate clathrin-mediated internalisation — inhibition of MT1-MMP internalisation

    Directory of Open Access Journals (Sweden)

    Ferrigno Paul

    2010-07-01

    Full Text Available Abstract Background Peptide aptamers are combinatorial protein reagents that bind to targets with a high specificity and a strong affinity thus providing a molecular tool kit for modulating the function of their targets in vivo. Results Here we report the isolation of a peptide aptamer named swiggle that interacts with the very short (21 amino acid long intracellular domain of membrane type 1-metalloproteinase (MT1-MMP, a key cell surface protease involved in numerous and crucial physiological and pathological cellular events. Expression of swiggle in mammalian cells was found to increase the cell surface expression of MT1-MMP by impairing its internalisation. Swiggle interacts with the LLY573 internalisation motif of MT1-MMP intracellular domain, thus disrupting the interaction with the μ2 subunit of the AP-2 internalisation complex required for endocytosis of the protease. Interestingly, swiggle-mediated inhibition of MT1-MMP clathrin-mediated internalisation was also found to promote MT1-MMP-mediated cell migration. Conclusions Taken together, our results provide further evidence that peptide aptamers can be used to dissect molecular events mediated by individual protein domains, in contrast to the pleiotropic effects of RNA interference techniques.

  9. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...... pocket, its carbonyl group aligning improperly relative to Ser195 and the oxyanion hole, explaining why the peptide is an inhibitor rather than a substrate. Substitution of the P1 Arg with novel unnatural Arg analogues with aliphatic or aromatic ring structures led to an increased affinity, depending......, in spite of a less favorable binding entropy and loss of a polar interaction. We conclude that increased flexibility of the peptide allows more favorable exosite interactions, which, in combination with the use of novel Arg analogues as P1 residues, can be used to manipulate the affinity and specificity...

  10. Mimicking the membrane-mediated conformation of dynorphin A-(1-13)-peptide: Circular dichroism and nuclear magnetic resonance studies in methanolic solution

    International Nuclear Information System (INIS)

    Lancaster, C.R.D.; Hughes, D.W.; Epand, R.M.; Mishra, P.K.; Bothner-By, A.A.; St Pierre, S.A.

    1991-01-01

    The structural requirements for the binding of dynorphin to the κ-opioid receptor are of profound clinical interest in the search for a powerful nonaddictive analgesic. These requirements are thought to be met by the membrane-mediated conformation of the opioid peptide dynorphin A-(1-13)-peptide, Tyr 1 -Gly 2 -Gly 3 -Phe 4 -Leu 5 -Arg 6 -Arg 7 -Ile 8 -Arg 9 -Pro 10 -Lys 11 -Leu 12 -Lys 13 . Schwyzer has proposed an essentially α-helical membrane-mediated conformation of the 13 amino acid peptide. In the present study, circular dichroism (CD) studies on dynorphin A-(1-13)-peptide bound to an anionic phospholipid signified negligible helical content of the peptide. CD studies also demonstrated that the aqueous-membraneous interphase may be mimicked by methanol. The 500- and 620-MHz 1 H nuclear magnetic resonance (NMR) spectra of dynorphin A-(1-13)-peptide in methanolic solution were sequence-specifically assigned with the aid of correlated spectroscopy (COSY), double-quantum filtered phase-sensitive COSY (DQF-COSY), relayed COSY (RELAY), and nuclear Overhauser enhancement spectroscopy (NOESY). 2-D CAMELSPIN/ROESY experiments indicated that at least the part of the molecule from Arg 7 to Arg 9 was in an extended or β-strand conformation, which agreed with deuterium-exchange and temperature-dependence studies of the amide protons and analysis of the vicinal spin-spin coupling constants 3 J HNα . The results clearly demonstrated the absence of extensive α-helix formation. χ 1 rotamer analysis of the 3 J αβ demonstrated no preferred side-chain conformations

  11. Development of novel ligands for peptide GPCRs.

    Science.gov (United States)

    Moran, Brian M; McKillop, Aine M; O'Harte, Finbarr Pm

    2016-12-01

    Incretin based glucagon-like peptide-1 receptor (GLP-1R) agonists which target a G-protein coupled receptor (GPCR) are currently used in the treatment of type 2 diabetes. This review focuses on GPCRs from pancreatic β-cells, including GLP-1, glucose-dependent insulinotropic polypeptide (GIP), glucagon, somatostatin, pancreatic polypeptide (PP), cholecystokinin (CCK), peptide YY (PYY), oxyntomodulin (OXM) and ghrelin receptors. In addition, fatty acids GPCRs are thought to have an increasing role in regulating peptide secretions namely short fatty acids GPCR (GPR41, GPR43), medium chain fatty acid GPCR (GPR84), long chain fatty acid GPCR (GPR40, GPR120) and cannabinoid-like GPCR (GPR55, GPR119). Several pre-clinical and clinical trials are currently ongoing in peptide GPCR based therapies, including dual and triple agonist peptides which activate two or more GPCRs simultaneously. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Isolation and characterization of enterocin W, a novel two-peptide lantibiotic produced by Enterococcus faecalis NKR-4-1.

    Science.gov (United States)

    Sawa, Naruhiko; Wilaipun, Pongtep; Kinoshita, Seisuke; Zendo, Takeshi; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

    2012-02-01

    Enterococcus faecalis NKR-4-1 isolated from pla-ra produces a novel two-peptide lantibiotic, termed enterocin W, comprising Wα and Wβ. The structure of enterocin W exhibited similarity with that of plantaricin W. The two peptides acted synergistically, and their order of binding to the cell membrane was important for their inhibitory activity.

  13. An optimized method for measuring hypocretin-1 peptide in the mouse brain reveals differential circadian regulation of hypocretin-1 levels rostral and caudal to the hypothalamus.

    Science.gov (United States)

    Justinussen, J L; Holm, A; Kornum, B R

    2015-12-03

    The hypocretin/orexin system regulates, among other things, sleep and energy homeostasis. The system is likely regulated by both homeostatic and circadian mechanisms. Little is known about local differences in the regulation of hypocretin activity. The aim of this study was to establish an optimized peptide quantification method for hypocretin-1 extracted from different mouse brain areas and use this method for investigating circadian fluctuations of hypocretin-1 levels in these areas. The results show that hypocretin-1 peptide can be extracted from small pieces of intact tissue, with sufficient yield for measurements in a standard radioimmunoassay. Utilizing the optimized method, it was found that prepro-hypocretin mRNA and peptide show circadian fluctuations in the mouse brain. This study further demonstrates that the hypocretin-1 peptide level in the frontal brain peaks during dark as does prepro-hypocretin mRNA in the hypothalamus. However, in midbrain and brainstem tissue caudal to the hypothalamus, there was less circadian fluctuation and a tendency for higher levels during the light phase. These data suggest that regulation of the hypocretin system differs between brain areas. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Novel Zn2+-chelating peptides selected from a fimbria-displayed random peptide library

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Schembri, Mark; Klemm, Per

    2001-01-01

    The display of peptide sequences on the surface of bacteria is a technology that offers exciting applications in biotechnology and medical research. Type 1 fimbriae are surface organelles of Escherichia coli which mediate D-mannose-sensitive binding to different host surfaces by virtue of the Fim......H adhesin. FimH is a component of the fimbrial organelle that can accommodate and display a diverse range of peptide sequences on the E. coli cell surface. In this study we have constructed a random peptide library in FimH. The library, consisting of similar to 40 million individual clones, was screened...

  15. Peptide array-based interaction assay of solid-bound peptides and anchorage-dependant cells and its effectiveness in cell-adhesive peptide design.

    Science.gov (United States)

    Kato, Ryuji; Kaga, Chiaki; Kunimatsu, Mitoshi; Kobayashi, Takeshi; Honda, Hiroyuki

    2006-06-01

    Peptide array, the designable peptide library covalently synthesized on cellulose support, was applied to assay peptide-cell interaction, between solid-bound peptides and anchorage-dependant cells, to study objective peptide design. As a model case, cell-adhesive peptides that could enhance cell growth as tissue engineering scaffold material, was studied. On the peptide array, the relative cell-adhesion ratio of NIH/3T3 cells was 2.5-fold higher on the RGDS (Arg-Gly-Asp-Ser) peptide spot as compared to the spot with no peptide, thus indicating integrin-mediated peptide-cell interaction. Such strong cell adhesion mediated by the RGDS peptide was easily disrupted by single residue substitution on the peptide array, thus indicating that the sequence recognition accuracy of cells was strictly conserved in our optimized scheme. The observed cellular morphological extension with active actin stress-fiber on the RGD motif-containing peptide supported our strategy that peptide array-based interaction assay of solid-bound peptide and anchorage-dependant cells (PIASPAC) could provide quantitative data on biological peptide-cell interaction. The analysis of 180 peptides obtained from fibronectin type III domain (no. 1447-1629) yielded 18 novel cell-adhesive peptides without the RGD motif. Taken together with the novel candidates, representative rules of ineffective amino acid usage were obtained from non-effective candidate sequences for the effective designing of cell-adhesive peptides. On comparing the amino acid usage of the top 20 and last 20 peptides from the 180 peptides, the following four brief design rules were indicated: (i) Arg or Lys of positively charged amino acids (except His) could enhance cell adhesion, (ii) small hydrophilic amino acids are favored in cell-adhesion peptides, (iii) negatively charged amino acids and small amino acids (except Gly) could reduce cell adhesion, and (iv) Cys and Met could be excluded from the sequence combination since they have

  16. Andrographolide inhibits hypoxia-induced HIF-1α-driven endothelin 1 secretion by activating Nrf2/HO-1 and promoting the expression of prolyl hydroxylases 2/3 in human endothelial cells.

    Science.gov (United States)

    Lin, Hung-Chih; Su, Shih-Li; Lu, Chia-Yang; Lin, Ai-Hsuan; Lin, Wan-Chun; Liu, Chin-San; Yang, Ya-Chen; Wang, Hsiu-Miao; Lii, Chong-Kuei; Chen, Haw-Wen

    2017-03-01

    Andrographolide, the main bioactive component of the medicinal plant Andrographis paniculata, has been shown to possess potent anti-inflammatory activity. Endothelin 1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, displays proinflammatory property. Hypoxia-inducible factor 1α (HIF-1α), the regulatory member of the transcription factor heterodimer HIF-1α/β, is one of the most important molecules that responds to hypoxia. Changes in cellular HIF-1α protein level are the result of altered gene transcription and protein stability, with the latter being dependent on prolyl hydroxylases (PHDs). In this study, inhibition of pro-inflammatory ET-1 expression and changes of HIF-1α gene transcription and protein stability under hypoxia by andrographolide in EA.hy926 endothelial-like cells were investigated. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl 2. We found that hypoxia stimulated the production of reactive oxygen species (ROS), the expression of HIF-1α mRNA and protein, and the expression and secretion of ET-1. These effects, however, were attenuated by co-exposure to andrographolide, bilirubin, and RuCO. Silencing Nrf2 and heme oxygenase 1 (HO-1) reversed the inhibitory effects of andrographolide on hypxoia-induced HIF-1α mRNA and protein expression. Moreover, andrographolide increased the expression of prolyl hydroxylases (PHD) 2/3, which hydroxylate HIF-1α and promotes HIF-1α proteasome degradation, with an increase in HIF-1α hydroxylation was noted under hypoxia. Inhibition of p38 MAPK abrogated the hypoxia-induced increases in HIF-1α mRNA and protein expression as well as ET-1 mRNA expression and secretion. Taken together, these results suggest that andrographolide suppresses hypoxia-induced pro-inflammatory ET-1 expression by activating Nrf2/HO-1, inhibiting p38 MAPK signaling, and promoting PHD2/3 expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 918-930, 2017. © 2016 Wiley

  17. Glucagon-like peptide-1 analogs against antipsychotic-induced weight gain

    DEFF Research Database (Denmark)

    Ebdrup, Bjørn H; Knop, Filip K; Ishøy, Pelle L

    2012-01-01

    between schizophrenia and overweight patients. DISCUSSION: Current interventions against antipsychotic-induced weight gain do not facilitate a substantial and lasting weight loss. GLP-1 analogues used in the treatment of type 2 diabetes are associated with significant and sustained weight loss...... are already compromised in normal weight patients with schizophrenia. Here we outline the current strategies against antipsychotic-induced weight gain, and we describe peripheral and cerebral effects of the gut hormone glucagon-like peptide-1 (GLP-1). Moreover, we account for similarities in brain changes...... in overweight patients. Potential effects of treating schizophrenia patients with antipsychotic-induced weight gain with GLP-1 analogues are discussed. CONCLUSIONS: We propose that adjunctive treatment with GLP-1 analogues may constitute a new avenue to treat and prevent metabolic and cerebral deficiencies...

  18. Interference with RUNX1/ETO Leukemogenic Function by Cell-Penetrating Peptides Targeting the NHR2 Oligomerization Domain

    Directory of Open Access Journals (Sweden)

    Yvonne Bartel

    2013-01-01

    Full Text Available The leukemia-associated fusion protein RUNX1/ETO is generated by the chromosomal translocation t(8;21 which appears in about 12% of all de novo acute myeloid leukemias (AMLs. Essential for the oncogenic potential of RUNX1/ETO is the oligomerization of the chimeric fusion protein through the nervy homology region 2 (NHR2 within ETO. In previous studies, we have shown that the intracellular expression of peptides containing the NHR2 domain inhibits RUNX1/ETO oligomerization, thereby preventing cell proliferation and inducing differentiation of RUNX1/ETO transformed cells. Here, we show that introduction of a recombinant TAT-NHR2 fusion polypeptide into the RUNX1/ETO growth-dependent myeloid cell line Kasumi-1 results in decreased cell proliferation and increased numbers of apoptotic cells. This effect was highly specific and mediated by binding the TAT-NHR2 peptide to ETO sequences, as TAT-polypeptides containing the oligomerization domain of BCR did not affect cell proliferation or apoptosis in Kasumi-1 cells. Thus, the selective interference with NHR2-mediated oligomerization by peptides represents a challenging but promising strategy for the inhibition of the leukemogenic potential of RUNX1/ETO in t(8;21-positive leukemia.

  19. Albumin-derived peptides efficiently reduce renal uptake of radiolabelled peptides

    International Nuclear Information System (INIS)

    Vegt, Erik; Eek, Annemarie; Oyen, Wim J.G.; Gotthardt, Martin; Boerman, Otto C.; Jong, Marion de

    2010-01-01

    In peptide-receptor radionuclide therapy (PRRT), the maximum activity dose that can safely be administered is limited by high renal uptake and retention of radiolabelled peptides. The kidney radiation dose can be reduced by coinfusion of agents that competitively inhibit the reabsorption of radiolabelled peptides, such as positively charged amino acids, Gelofusine, or trypsinised albumin. The aim of this study was to identify more specific and potent inhibitors of the kidney reabsorption of radiolabelled peptides, based on albumin. Albumin was fragmented using cyanogen bromide and six albumin-derived peptides with different numbers of electric charges were selected and synthesised. The effect of albumin fragments (FRALB-C) and selected albumin-derived peptides on the internalisation of 111 In-albumin, 111 In-minigastrin, 111 In-exendin and 111 In-octreotide by megalin-expressing cells was assessed. In rats, the effect of Gelofusine and albumin-derived peptides on the renal uptake and biodistribution of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide was determined. FRALB-C significantly reduced the uptake of all radiolabelled peptides in vitro. The albumin-derived peptides showed different potencies in reducing the uptake of 111 In-albumin, 111 In-exendin and 111 In-minigastrin in vitro. The most efficient albumin-derived peptide (peptide 6), was selected for in vivo testing. In rats, 5 mg of peptide 6 very efficiently inhibited the renal uptake of 111 In-minigastrin, by 88%. Uptake of 111 In-exendin and 111 In-octreotide was reduced by 26 and 33%, respectively. The albumin-derived peptide 6 efficiently inhibited the renal reabsorption of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide and is a promising candidate for kidney protection in PRRT. (orig.)

  20. Membrane interactions of a self-assembling model peptide that mimics the self-association, structure and toxicity of Aβ(1-40)

    Science.gov (United States)

    Salay, Luiz C.; Qi, Wei; Keshet, Ben; Tamm, Lukas K.; Fernandez, Erik J.

    2013-01-01

    β-amyloid peptide (Aβ) is a primary protein component of senile plaques in Alzheimer’s disease (AD) and plays an important, but not fully understood role in neurotoxicity. Model peptides with the demonstrated ability to mimic the structural and toxicity behavior of Aβ could provide a means to evaluate the contributions to toxicity that are common to self–associating peptides from many disease states. In this work, we have studied the peptide-membrane interactions of a model β-sheet peptide, P11-2 (CH3CO-Gln-Gln-Arg-Phe-Gln-Trp-Gln-Phe-Glu-Gln-Gln-NH2), by fluorescence, infrared spectroscopy, and hydrogen-deuterium exchange. Like Aβ(1-40), the peptide is toxic, and conditions which produce intermediate oligomers show higher toxicity against cells than either monomeric forms or higher aggregates of the peptide. Further, P11-2 also binds to both zwitterionic (POPC) and negatively charged (POPC:POPG) liposomes, acquires a partial β-sheet conformation in presence of lipid, and is protected against deuterium exchange in the presence of lipids. The results show that a simple rationally designed model β-sheet peptide recapitulates many important features of Aβ peptide structure and function, reinforcing the idea that toxicity arises, at least in part, from a common mode of action on membranes that is independent of specific aspects of the amino acid sequence. Further studies of such well-behaved model peptide systems will facilitate the investigation of the general principles that govern the molecular interactions of aggregation-prone disease-associated peptides with cell and/or membrane surfaces. PMID:19393615

  1. Mutational analysis of hepatitis B virus pre-S1 (9–24) fusogenic peptide

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qiushi; Somiya, Masaharu [The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047 (Japan); Shimada, Naohiko; Sakamoto, Wakako [Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 B-57, Nagatsuta, Midori, Yokohama 226-8501 (Japan); Yoshimoto, Nobuo; Iijima, Masumi; Tatematsu, Kenji; Nakai, Tadashi; Okajima, Toshihide [The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047 (Japan); Maruyama, Atsushi [Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 B-57, Nagatsuta, Midori, Yokohama 226-8501 (Japan); Kuroda, Shuńichi, E-mail: skuroda@sanken.osaka-u.ac.jp [The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047 (Japan)

    2016-05-27

    A hollow nanoparticle known as a bio-nanocapsule (BNC) consisting of hepatitis B virus (HBV) envelope L protein and liposome (LP) can encapsulate drugs and genes and thereby deliver them in vitro and in vivo to human hepatic tissues, specifically by utilizing the HBV-derived infection machinery. Recently, we identified a low pH-dependent fusogenic domain at the N-terminal part of the pre-S1 region of the HBV L protein (amino acid residues 9 to 24; NPLGFFPDHQLDPAFG), which shows membrane destabilizing activity (i.e., membrane fusion, membrane disruption, and payload release) upon interaction with target LPs. In this study, instead of BNC and HBV, we generated LPs displaying a mutated form of the pre-S1 (9–24) peptide, and performed a membrane disruption assay using target LPs containing pyranine (fluorophore) and p-xylene-bis (N-pyridinium bromide) (DPX) as a quencher. The membrane disruption activity was found to correlate with the hydrophobicity of the whole structure, while the peptide retained a random-coil structure even under low pH condition. One large hydrophobic cluster (I) and one small hydrophobic cluster (II) residing in the peptide would be connected by the protonation of residues D16 and D20, and thereby exhibit strong membrane disruption activity in a low pH-dependent manner. Furthermore, the introduction of a positively charged residue enhanced the activity significantly, suggesting that a sole positively charged residue (H17) may be important for the interaction with target LPs by electrostatic interaction. Collectively, these results suggest that the pre-S1 (9–24) peptide may be involved in the endosomal escape of the BNC's payloads, as well as in the HBV uncoating process. -- Highlights: •Low pH-dependent fusogenic domain of hepatitis B virus pre-S1 region is analyzed. •The domain resides in pre-S1 (9–24) region, exhibiting random-coil structure. •Membrane disruption activity of the domain is mainly driven by its hydrophobicity

  2. Peptide profiling of bovine kefir reveals 236 unique peptides released from caseins during its production by starter culture or kefir grains.

    Science.gov (United States)

    Ebner, Jennifer; Aşçı Arslan, Ayşe; Fedorova, Maria; Hoffmann, Ralf; Küçükçetin, Ahmet; Pischetsrieder, Monika

    2015-03-18

    Kefir has a long tradition in human nutrition due to its presupposed health promoting effects. To investigate the potential contribution of bioactive peptides to the physiological effects of kefir, comprehensive analysis of the peptide profile was performed by nano-ESI-LTQ-Orbitrap MS coupled to nano-ultrahigh-performance liquid chromatography. Thus, 257 peptides were identified, mainly released from β-casein, followed by αS1-, κ-, and αS2-casein. Most (236) peptides were uniquely detected in kefir, but not in raw milk indicating that the fermentation step does not only increase the proteolytic activity 1.7- to 2.4-fold compared to unfermented milk, but also alters the composition of the peptide fraction. The influence of the microflora was determined by analyzing kefir produced from traditional kefir grains or commercial starter culture. Kefir from starter culture featured 230 peptide sequences and showed a significantly, 1.4-fold higher proteolytic activity than kefir from kefir grains with 127 peptides. A match of 97 peptides in both varieties indicates the presence of a typical kefir peptide profile that is not influenced by the individual composition of the microflora. Sixteen of the newly identified peptides were previously described as bioactive, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, immunomodulating, opioid, mineral binding, antioxidant, and antithrombotic effects. The present study describes a comprehensive peptide profile of kefir comprising 257 sequences. The peptide list was used to identify 16 bioactive peptides with ACE-inhibitory, antioxidant, antithrombotic, mineral binding, antimicrobial, immunomodulating and opioid activity in kefir. Furthermore, it was shown that a majority of the kefir peptides were not endogenously present in the raw material milk, but were released from milk caseins by proteases of the microbiota and are therefore specific for the product. Consequently, the proteolytic activity and the

  3. PeptideNavigator: An interactive tool for exploring large and complex data sets generated during peptide-based drug design projects.

    Science.gov (United States)

    Diller, Kyle I; Bayden, Alexander S; Audie, Joseph; Diller, David J

    2018-01-01

    There is growing interest in peptide-based drug design and discovery. Due to their relatively large size, polymeric nature, and chemical complexity, the design of peptide-based drugs presents an interesting "big data" challenge. Here, we describe an interactive computational environment, PeptideNavigator, for naturally exploring the tremendous amount of information generated during a peptide drug design project. The purpose of PeptideNavigator is the presentation of large and complex experimental and computational data sets, particularly 3D data, so as to enable multidisciplinary scientists to make optimal decisions during a peptide drug discovery project. PeptideNavigator provides users with numerous viewing options, such as scatter plots, sequence views, and sequence frequency diagrams. These views allow for the collective visualization and exploration of many peptides and their properties, ultimately enabling the user to focus on a small number of peptides of interest. To drill down into the details of individual peptides, PeptideNavigator provides users with a Ramachandran plot viewer and a fully featured 3D visualization tool. Each view is linked, allowing the user to seamlessly navigate from collective views of large peptide data sets to the details of individual peptides with promising property profiles. Two case studies, based on MHC-1A activating peptides and MDM2 scaffold design, are presented to demonstrate the utility of PeptideNavigator in the context of disparate peptide-design projects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. A liver metalloendopeptidase which degrades the circulating hypotensive peptide hormones bradykinin and atrial natriuretic peptide

    Directory of Open Access Journals (Sweden)

    Carvalho K.M.

    1999-01-01

    Full Text Available A new metalloendopeptidase was purified to apparent homogeneity from a homogenate of normal human liver using successive steps of chromatography on DEAE-cellulose, hydroxyapatite and Sephacryl S-200. The purified enzyme hydrolyzed the Pro7-Phe8 bond of bradykinin and the Ser25-Tyr26 bond of atrial natriuretic peptide. No cleavage was produced in other peptide hormones such as vasopressin, oxytocin or Met- and Leu-enkephalin. This enzyme activity was inhibited by 1 mM divalent cation chelators such as EDTA, EGTA and o-phenanthroline and was insensitive to 1 µM phosphoramidon and captopril, specific inhibitors of neutral endopeptidase (EC 3.4.24.11 and angiotensin-converting enzyme (EC 3.4.15.1, respectively. With Mr 85 kDa, the enzyme exhibits optimal activity at pH 7.5. The high affinity of this endopeptidase for bradykinin (Km = 10 µM and for atrial natriuretic peptide (Km = 5 µM suggests that it may play a physiological role in the inactivation of these circulating hypotensive peptide hormones.

  5. Peptide YY receptors in the brain

    International Nuclear Information System (INIS)

    Inui, A.; Oya, M.; Okita, M.

    1988-01-01

    Radiolabelled ligand binding studies demonstrated that specific receptors for peptide YY are present in the porcine as well as the canine brains. Peptide YY was bound to brain tissue membranes via high-affinity (dissociation constant, 1.39 X 10(-10)M) and low-affinity (dissociation constant, 3.72 X 10(-8)M) components. The binding sites showed a high specificity for peptide YY and neuropeptide Y, but not for pancreatic polypeptide or structurally unrelated peptides. The specific activity of peptide YY binding was highest in the hippocampus, followed by the pituitary gland, the hypothalamus, and the amygdala of the porcine brain, this pattern being similarly observed in the canine brain. The results suggest that peptide YY and neuropeptide Y may regulate the function of these regions of the brain through interaction with a common receptor site

  6. Circulating fibroblast growth factor-23 is associated with increased risk for metachronous colorectal adenoma

    Directory of Open Access Journals (Sweden)

    Elizabeth Jacobs

    2011-01-01

    Full Text Available Background: Fibroblast growth factor-23 (FGF-23 is a phosphaturic peptide and a key component of an endocrine feedback loop along with the hormonal vitamin D metabolite 1,25(OH 2 D. Vitamin D has been shown to be inversely related to colorectal neoplasia; therefore, we hypothesized that the effect of FGF-23 on vitamin D metabolite concentrations could have implications for the risk of colorectal neoplasia. Materials and Methods: The purpose of this study was to prospectively evaluate the association between circulating concentrations of FGF-23 and the risk of metachronous (recurrent colorectal adenomas. FGF-23 levels were assessed in 100 male and female participants from the Ursodeoxycholic Acid Trial, 50 of whom had a metachronous colorectal adenoma and 50 who did not. Results: Compared to the lowest tertile of FGF-23, the adjusted odds ratios (95% CIs for the second and third tertiles were 2.80 (0.94 to 8.31 and 3.41 (1.09 to 10.67, respectively (P-trend=.03. In a linear regression model, there was also a statistically significant inverse relationship between FGF-23 and 1,25(OH 2 D (β-coefficient=-1.2; P=.001. In contrast, no statistically significant trend was observed between FGF-23 and 25(OHD concentrations (β-coefficient=0.55; P=.10. Conclusions: The current work presents novel preliminary evidence of a relationship between FGF-23 and the risk for colorectal neoplasia. FGF-23 activity may be mediated through biologic effects on individual serum and colonic 1,25(OH 2 D levels, or it may be independent from the vitamin D pathway. Further studies in larger populations are necessary for confirmation and expansion of these hypothesis-generating results.

  7. Water accessibility in a membrane-inserting peptide comparing Overhauser DNP and pulse EPR methods

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Takuya F., E-mail: takuya.segawa@alumni.ethz.ch; Doppelbauer, Maximilian; Garbuio, Luca; Doll, Andrin; Polyhach, Yevhen O.; Jeschke, Gunnar, E-mail: gjeschke@ethz.ch [Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich (Switzerland)

    2016-05-21

    Water accessibility is a key parameter for the understanding of the structure of biomolecules, especially membrane proteins. Several experimental techniques based on the combination of electron paramagnetic resonance (EPR) spectroscopy with site-directed spin labeling are currently available. Among those, we compare relaxation time measurements and electron spin echo envelope modulation (ESEEM) experiments using pulse EPR with Overhauser dynamic nuclear polarization (DNP) at X-band frequency and a magnetic field of 0.33 T. Overhauser DNP transfers the electron spin polarization to nuclear spins via cross-relaxation. The change in the intensity of the {sup 1}H NMR spectrum of H{sub 2}O at a Larmor frequency of 14 MHz under a continuous-wave microwave irradiation of the nitroxide spin label contains information on the water accessibility of the labeled site. As a model system for a membrane protein, we use the hydrophobic α-helical peptide WALP23 in unilamellar liposomes of DOPC. Water accessibility measurements with all techniques are conducted for eight peptides with different spin label positions and low radical concentrations (10–20 μM). Consistently in all experiments, the water accessibility appears to be very low, even for labels positioned near the end of the helix. The best profile is obtained by Overhauser DNP, which is the only technique that succeeds in discriminating neighboring positions in WALP23. Since the concentration of the spin-labeled peptides varied, we normalized the DNP parameter ϵ, being the relative change of the NMR intensity, by the electron spin concentration, which was determined from a continuous-wave EPR spectrum.

  8. Effects of amantadine on the dynamics of membrane-bound influenza A M2 transmembrane peptide studied by NMR relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Cady, Sarah D.; Hong Mei [Iowa State University, Department of Chemistry (United States)], E-mail: mhong@iastate.edu

    2009-09-15

    The molecular motions of membrane proteins in liquid-crystalline lipid bilayers lie at the interface between motions in isotropic liquids and in solids. Specifically, membrane proteins can undergo whole-body uniaxial diffusion on the microsecond time scale. In this work, we investigate the {sup 1}H rotating-frame spin-lattice relaxation (T{sub 1{rho}}) caused by the uniaxial diffusion of the influenza A M2 transmembrane peptide (M2TMP), which forms a tetrameric proton channel in lipid bilayers. This uniaxial diffusion was proved before by {sup 2}H, {sup 15}N and {sup 13}C NMR lineshapes of M2TMP in DLPC bilayers. When bound to an inhibitor, amantadine, the protein exhibits significantly narrower linewidths at physiological temperature. We now investigate the origin of this line narrowing through temperature-dependent {sup 1}H T{sub 1{rho}} relaxation times in the absence and presence of amantadine. Analysis of the temperature dependence indicates that amantadine decreases the correlation time of motion from 2.8 {+-} 0.9 {mu}s for the apo peptide to 0.89 {+-} 0.41 {mu}s for the bound peptide at 313 K. Thus the line narrowing of the bound peptide is due to better avoidance of the NMR time scale and suppression of intermediate time scale broadening. The faster diffusion of the bound peptide is due to the higher attempt rate of motion, suggesting that amantadine creates better-packed and more cohesive helical bundles. Analysis of the temperature dependence of ln (T{sub 1{rho}}{sup -1}) indicates that the activation energy of motion increased from 14.0 {+-} 4.0 kJ/mol for the apo peptide to 23.3 {+-} 6.2 kJ/mol for the bound peptide. This higher activation energy indicates that excess amantadine outside the protein channel in the lipid bilayer increases the membrane viscosity. Thus, the protein-bound amantadine speeds up the diffusion of the helical bundles while the excess amantadine in the bilayer increases the membrane viscosity.

  9. Control of phospholipid flip-flop by transmembrane peptides

    International Nuclear Information System (INIS)

    Kaihara, Masanori; Nakao, Hiroyuki; Yokoyama, Hirokazu; Endo, Hitoshi; Ishihama, Yasushi; Handa, Tetsurou; Nakano, Minoru

    2013-01-01

    Highlights: ► Phospholipid flip-flop in transmembrane peptide-containing vesicles was investigated. ► Peptides that contained polar residues in the center of the transmembrane region promoted phospholipid flip-flop. ► A bioinformatics approach revealed the presence of polar residues in the transmembrane region of ER membrane proteins. ► Polar residues in ER membrane proteins possibly provide flippase-like activity. - Abstract: We designed three types of transmembrane model peptides whose sequence originates from a frequently used model peptide KALP23, and we investigated their effects on phospholipid flip-flop. Time-resolved small-angle neutron scattering and a dithionite fluorescent quenching assay demonstrated that TMP-L, which has a fully hydrophobic transmembrane region, did not enhance phospholipid flip-flop, whereas TMP-K and TMP-E, which have Lys and Glu, respectively, in the center of their transmembrane regions, enhanced phospholipid flip-flop. Introduction of polar residues in the membrane-spanning helices is considered to produce a locally polar region and enable the lipid head group to interact with the polar side-chain inside the bilayers, thereby reducing the activation energy for the flip-flop. A bioinformatics approach revealed that acidic and basic residues account for 4.5% of the central region of the transmembrane domain in human ER membrane proteins. Therefore, polar residues in ER membrane proteins are considered to provide flippase-like activity

  10. CopA3 Peptide Prevents Ultraviolet-Induced Inhibition of Type-I Procollagen and Induction of Matrix Metalloproteinase-1 in Human Skin Fibroblasts

    Directory of Open Access Journals (Sweden)

    Dong-Hee Kim

    2014-05-01

    Full Text Available Ultraviolet (UV exposure is well-known to induce premature aging, which is mediated by matrix metalloproteinase-1 (MMP-1 activity. A 9-mer peptide, CopA3 (CopA3 was synthesized from a natural peptide, coprisin, which is isolated from the dung beetle Copris tripartitus. As part of our continuing search for novel bioactive natural products, CopA3 was investigated for its in vitro anti-skin photoaging activity. UV-induced inhibition of type-I procollagen and induction of MMP-1 were partially prevented in human skin fibroblasts by CopA3 peptide in a dose-dependent manner. At a concentration of 25 μM, CopA3 nearly completely inhibited MMP-1 expression. These results suggest that CopA3, an insect peptide, is a potential candidate for the prevention and treatment of skin aging.

  11. Annexin A1 N-terminal derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions.

    Directory of Open Access Journals (Sweden)

    Valentina Bizzarro

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we have evaluated whether Annexin A1 derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions. Using normal human skin fibroblasts WS1 in low glucose (LG or high glucose (HG we observed the enrichment of Annexin A1 protein at cell movement structures like lamellipodial extrusions and interestingly, a significant decrease in levels of the protein in HG conditions. The analysis of the translocation of Annexin A1 to cell membrane showed lower levels of Annexin A1 in both membrane pool and supernatants of WS1 cells treated with HG. Wound-healing assays using cell line transfected with Annexin A1 siRNAs indicated a slowing down in migration speed of cells suggesting that Annexin A1 has a role in the migration of WS1 cells. In order to analyze the role of extracellular Annexin A1 in cell migration, we have performed wound-healing assays using Ac2-26 showing that peptide was able to increase fibroblast cell migration in HG conditions. Experiments on the mobilization of intracellular calcium and analysis of p-ERK expression confirmed the activity of the FPR1 following stimulation with the peptide Ac2-26. A wound-healing assay on WS1 cells in the presence of the FPR agonist fMLP, of the FPR antagonist CsH and in the presence of Ac2-26 indicated that Annexin A1 influences fibroblast cell migration under HG conditions acting through FPR receptors whose expression was slightly increased in HG. In conclusion, these data demonstrate that (i Annexin A1 is involved in migration of WS1 cells, through interaction with FPRs; (ii N- terminal peptide of Annexin A1 Ac2-26 is able to stimulate direct migration of WS1 cells in high glucose treatment possibly due to the increased receptor expression observed in hyperglycemia conditions.

  12. Interactions of Bio-Inspired Membranes with Peptides and Peptide-Mimetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael Sebastiano

    2015-08-01

    Full Text Available Via Dissipative Particle Dynamics (DPD and implicit solvent coarse-grained (CG Molecular Dynamics (MD we examine the interaction of an amphiphilic cell-penetrating peptide PMLKE and its synthetic counterpart with a bio-inspired membrane. We use the DPD technique to investigate the interaction of peptide-mimetic nanoparticles, or nanopins, with a three-component membrane. The CG MD approach is used to investigate the interaction of a cell-penetrating peptide PMLKE with single-component membrane. We observe the spontaneous binding and subsequent insertion of peptide and nanopin in the membrane by using CG MD and DPD approaches, respectively. In addition, we find that the insertion of peptide and nanopins is mainly driven by the favorable enthalpic interactions between the hydrophobic components of the peptide, or nanopin, and the membrane. Our study provides insights into the mechanism underlying the interactions of amphiphilic peptide and peptide-mimetic nanoparticles with a membrane. The result of this study can be used to guide the functional integration of peptide and peptide-mimetic nanoparticles with a cell membrane.

  13. THE USE OF DEDICATED PEPTIDE LIBRARIES PERMITS THE DISCOVERY OF HIGH-AFFINITY BINDING PEPTIDES

    NARCIS (Netherlands)

    DEKOSTER, HS; AMONS, R; BENCKHUIJSEN, WE; FEIJLBRIEF, M; SCHELLEKENS, GA; DRIJFHOUT, JW

    1995-01-01

    The motif for peptide binding to monoclonal antibody mAb A16, which is known to be directed against glycoprotein D of Herpes simplex virus type 1, was determined using two dedicated peptide libraries. As a starting point for this study we used an A-16 binding lead sequence, which had previously been

  14. Stability of transmembrane amyloid β-peptide and membrane integrity tested by molecular modeling of site-specific Aβ42 mutations.

    Directory of Open Access Journals (Sweden)

    Chetan Poojari

    Full Text Available Interactions of the amyloid β-protein (Aβ with neuronal cell membranes, leading to the disruption of membrane integrity, are considered to play a key role in the development of Alzheimer's disease. Natural mutations in Aβ42, such as the Arctic mutation (E22G have been shown to increase Aβ42 aggregation and neurotoxicity, leading to the early-onset of Alzheimer's disease. A correlation between the propensity of Aβ42 to form protofibrils and its effect on neuronal dysfunction and degeneration has been established. Using rational mutagenesis of the Aβ42 peptide it was further revealed that the aggregation of different Aβ42 mutants in lipid membranes results in a variety of polymorphic aggregates in a mutation dependent manner. The mutant peptides also have a variable ability to disrupt bilayer integrity. To further test the connection between Aβ42 mutation and peptide-membrane interactions, we perform molecular dynamics simulations of membrane-inserted Aβ42 variants (wild-type and E22G, D23G, E22G/D23G, K16M/K28M and K16M/E22G/D23G/K28M mutants as β-sheet monomers and tetramers. The effects of charged residues on transmembrane Aβ42 stability and membrane integrity are analyzed at atomistic level. We observe an increased stability for the E22G Aβ42 peptide and a decreased stability for D23G compared to wild-type Aβ42, while D23G has the largest membrane-disruptive effect. These results support the experimental observation that the altered toxicity arising from mutations in Aβ is not only a result of the altered aggregation propensity, but also originates from modified Aβ interactions with neuronal membranes.

  15. Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa biofilm formation.

    Science.gov (United States)

    Schillaci, Domenico; Cusimano, Maria Grazia; Spinello, Angelo; Barone, Giampaolo; Russo, Debora; Vitale, Maria; Parrinello, Daniela; Arizza, Vincenzo

    2014-01-01

    The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiofilm properties against reference strains of Gram positive and Gram negative. The Paracentrin 1 was active against planktonic form of staphylococcal strains (reference and isolates) and Pseudomonas aeruginosa ATCC 15442 at concentrations ranging from 12.5 to 6.2 mg/ml. The Paracentrin 1 was able to inhibit biofilm formation of staphylococcal and Pseudomonas aeruginosa strains at concentrations ranging from 3.1 to 0.75 mg/ml. We consider the tested peptide as a good starting molecule for novel synthetic derivatives with improved pharmaceutical potential.

  16. Peptide Based Radiopharmaceuticals: Specific Construct Approach

    Energy Technology Data Exchange (ETDEWEB)

    Som, P; Rhodes, B A; Sharma, S S

    1997-10-21

    The objective of this project was to develop receptor based peptides for diagnostic imaging and therapy. A series of peptides related to cell adhesion molecules (CAM) and immune regulation were designed for radiolabeling with 99mTc and evaluated in animal models as potential diagnostic imaging agents for various disease conditions such as thrombus (clot), acute kidney failure, and inflection/inflammation imaging. The peptides for this project were designed by the industrial partner, Palatin Technologies, (formerly Rhomed, Inc.) using various peptide design approaches including a newly developed rational computer assisted drug design (CADD) approach termed MIDAS (Metal ion Induced Distinctive Array of Structures). In this approach, the biological function domain and the 99mTc complexing domain are fused together so that structurally these domains are indistinguishable. This approach allows construction of conformationally rigid metallo-peptide molecules (similar to cyclic peptides) that are metabolically stable in-vivo. All the newly designed peptides were screened in various in vitro receptor binding and functional assays to identify a lead compound. The lead compounds were formulated in a one-step 99mTc labeling kit form which were studied by BNL for detailed in-vivo imaging using various animals models of human disease. Two main peptides usingMIDAS approach evolved and were investigated: RGD peptide for acute renal failure and an immunomodulatory peptide derived from tuftsin (RMT-1) for infection/inflammation imaging. Various RGD based metallopeptides were designed, synthesized and assayed for their efficacy in inhibiting ADP-induced human platelet aggregation. Most of these peptides displayed biological activity in the 1-100 µM range. Based on previous work by others, RGD-I and RGD-II were evaluated in animal models of acute renal failure. These earlier studies showed that after acute ischemic injury the renal cortex displays

  17. Diagnostic value of C-peptide determination. [Radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Kober, G; Rainer, O H [Landeskrankenhaus Klagenfurt (Austria). Nuklearmedizinische Abt.

    1983-01-01

    C-peptide and insulin serum determinations were performed in 94 glucagon-stimulated diabetics and in 15 healthy persons. A minimal increase of 1.5 ng C-peptide/ml serum after glucagon injection (1 mg i.v.) was found to be a useful parameter for the differentiation of insulin dependent and non-insulin dependent diabetics. The maximal response to glucagon occurred during the first 10-minutes after the injection (blood was drawn at 2-minutes intervals). Serum insulin levels and basal C-peptide concentrations were of no value in predicting insulin-dependency. Basal C-peptide levels were significantly different from control in juvenile insulin dependent diabetics (decrease) only.

  18. Novel Inhibitor Cystine Knot Peptides from Momordica charantia

    Science.gov (United States)

    Clark, Richard J.; Tang, Jun; Zeng, Guang-Zhi; Franco, Octavio L.; Cantacessi, Cinzia; Craik, David J.; Daly, Norelle L.; Tan, Ning-Hua

    2013-01-01

    Two new peptides, MCh-1 and MCh-2, along with three known trypsin inhibitors (MCTI-I, MCTI-II and MCTI-III), were isolated from the seeds of the tropical vine Momordica charantia. The sequences of the peptides were determined using mass spectrometry and NMR spectroscopy. Using a strategy involving partial reduction and stepwise alkylation of the peptides, followed by enzymatic digestion and tandem mass spectrometry sequencing, the disulfide connectivity of MCh-1 was elucidated to be CysI-CysIV, CysII-CysV and CysIII-CysVI. The three-dimensional structures of MCh-1 and MCh-2 were determined using NMR spectroscopy and found to contain the inhibitor cystine knot (ICK) motif. The sequences of the novel peptides differ significantly from peptides previously isolated from this plant. Therefore, this study expands the known peptide diversity in M. charantia and the range of sequences that can be accommodated by the ICK motif. Furthermore, we show that a stable two-disulfide intermediate is involved in the oxidative folding of MCh-1. This disulfide intermediate is structurally homologous to the proposed ancestral fold of ICK peptides, and provides a possible pathway for the evolution of this structural motif, which is highly prevalent in nature. PMID:24116036

  19. Novel inhibitor cystine knot peptides from Momordica charantia.

    Directory of Open Access Journals (Sweden)

    Wen-Jun He

    Full Text Available Two new peptides, MCh-1 and MCh-2, along with three known trypsin inhibitors (MCTI-I, MCTI-II and MCTI-III, were isolated from the seeds of the tropical vine Momordica charantia. The sequences of the peptides were determined using mass spectrometry and NMR spectroscopy. Using a strategy involving partial reduction and stepwise alkylation of the peptides, followed by enzymatic digestion and tandem mass spectrometry sequencing, the disulfide connectivity of MCh-1 was elucidated to be CysI-CysIV, CysII-CysV and CysIII-CysVI. The three-dimensional structures of MCh-1 and MCh-2 were determined using NMR spectroscopy and found to contain the inhibitor cystine knot (ICK motif. The sequences of the novel peptides differ significantly from peptides previously isolated from this plant. Therefore, this study expands the known peptide diversity in M. charantia and the range of sequences that can be accommodated by the ICK motif. Furthermore, we show that a stable two-disulfide intermediate is involved in the oxidative folding of MCh-1. This disulfide intermediate is structurally homologous to the proposed ancestral fold of ICK peptides, and provides a possible pathway for the evolution of this structural motif, which is highly prevalent in nature.

  20. STAT1, STAT3 and p38MAPK are involved in the apoptotic effect induced by a chimeric cyclic interferon-{alpha}2b peptide

    Energy Technology Data Exchange (ETDEWEB)

    Blank, Viviana C.; Pena, Clara [Institute of Biochemistry and Biophysics (UBA-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956-C1113AAD Buenos Aires (Argentina); Roguin, Leonor P., E-mail: rvroguin@qb.ffyb.uba.ar [Institute of Biochemistry and Biophysics (UBA-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956-C1113AAD Buenos Aires (Argentina)

    2010-02-15

    In the search of mimetic peptides of the interferon-{alpha}2b molecule (IFN-{alpha}2b), we have previously designed and synthesized a chimeric cyclic peptide of the IFN-{alpha}2b that inhibits WISH cell proliferation by inducing an apoptotic response. Here, we first studied the ability of this peptide to activate intracellular signaling pathways and then evaluated the participation of some signals in the induction of apoptosis. Stimulation of WISH cells with the cyclic peptide showed tyrosine phosphorylation of Jak1 and Tyk2 kinases, tyrosine and serine phosphorylation of STAT1 and STAT3 transcription factors and activation of p38 MAPK pathway, although phosphorylation levels or kinetics were in some conditions different to those obtained under IFN-{alpha}2b stimulus. JNK and p44/42 pathways were not activated by the peptide in WISH cells. We also showed that STAT1 and STAT3 downregulation by RNA interference decreased the antiproliferative activity and the amount of apoptotic cells induced by the peptide. Pharmacological inhibition of p38 MAPK also reduced the peptide growth inhibitory activity and the apoptotic effect. Thus, we demonstrated that the cyclic peptide regulates WISH cell proliferation through the activation of Jak/STAT signaling pathway. In addition, our results indicate that p38 MAPK may also be involved in cell growth regulation. This study suggests that STAT1, STAT3 and p38 MAPK would be mediating the antitumor and apoptotic response triggered by the cyclic peptide in WISH cells.

  1. STAT1, STAT3 and p38MAPK are involved in the apoptotic effect induced by a chimeric cyclic interferon-α2b peptide

    International Nuclear Information System (INIS)

    Blank, Viviana C.; Pena, Clara; Roguin, Leonor P.

    2010-01-01

    In the search of mimetic peptides of the interferon-α2b molecule (IFN-α2b), we have previously designed and synthesized a chimeric cyclic peptide of the IFN-α2b that inhibits WISH cell proliferation by inducing an apoptotic response. Here, we first studied the ability of this peptide to activate intracellular signaling pathways and then evaluated the participation of some signals in the induction of apoptosis. Stimulation of WISH cells with the cyclic peptide showed tyrosine phosphorylation of Jak1 and Tyk2 kinases, tyrosine and serine phosphorylation of STAT1 and STAT3 transcription factors and activation of p38 MAPK pathway, although phosphorylation levels or kinetics were in some conditions different to those obtained under IFN-α2b stimulus. JNK and p44/42 pathways were not activated by the peptide in WISH cells. We also showed that STAT1 and STAT3 downregulation by RNA interference decreased the antiproliferative activity and the amount of apoptotic cells induced by the peptide. Pharmacological inhibition of p38 MAPK also reduced the peptide growth inhibitory activity and the apoptotic effect. Thus, we demonstrated that the cyclic peptide regulates WISH cell proliferation through the activation of Jak/STAT signaling pathway. In addition, our results indicate that p38 MAPK may also be involved in cell growth regulation. This study suggests that STAT1, STAT3 and p38 MAPK would be mediating the antitumor and apoptotic response triggered by the cyclic peptide in WISH cells.

  2. Alpha S1-casein polymorphisms in camel (Camelus dromedarius) and descriptions of biological active peptides and allergenic epitopes.

    Science.gov (United States)

    Erhardt, Georg; Shuiep, El Tahir Salih; Lisson, Maria; Weimann, Christina; Wang, Zhaoxin; El Zubeir, Ibtisam El Yas Mohamed; Pauciullo, Alfredo

    2016-06-01

    Milk samples of 193 camels (Camelus dromedarius) from different regions of Sudan were screened for casein variability by isoelectric focusing. Kappa-casein and beta-casein were monomorphic, whereas three protein patterns named αs1-casein A, C, and D were identified. The major allele A revealed frequencies of 0.79 (Lahaoi), 0.75 (Shanbali), 0.90 (Arabi Khali), and 0.88 (Arabi Gharbawi) in the different ecotypes. CSN1S1*C shows a single G > T nucleotide substitution in the exon 5, leading to a non-synonymous amino acid exchange (p.Glu30 > Asp30) in comparison to CSN1S1*A and D. At cDNA level, no further single nucleotide polymorphisms could be identified in CSN1S1* A, C, and D, whereas the variants CSN1S1*A and CSN1S1*C are characterized by missing of exon 18 compared to the already described CSN1S1*B, as consequence of DNA insertion of 11 bp at intron 17 which alter the pre-mRNA spliceosome machinery. A polymerase chain-restriction fragment length polymorphism method (PCR-RFLP) was established to type for G > T nucleotide substitution at genomic DNA level. The occurrence and differences of IgE-binding epitopes and bioactive peptides between αs1-casein A, C, and D after digestion were analyzed in silico. The amino acid substitutions and deletion affected the arising peptide pattern and thus modifications between IgE-binding epitopes and bioactive peptides of the variants were found. The allergenic potential of these different peptides will be investigated by microarray immunoassay using sera from milk-sensitized individuals, as it was already demonstrated for bovine αs1-casein variants.

  3. Glucagon-like peptide-1 (GLP-1) raises blood-brain glucose transfer capacity and hexokinase activity in human brain

    OpenAIRE

    Gejl, Michael; Lerche, Susanne; Egefjord, L?rke; Brock, Birgitte; M?ller, Niels; Vang, Kim; Rodell, Anders B.; Bibby, Bo M.; Holst, Jens J.; Rungby, J?rgen; Gjedde, Albert

    2013-01-01

    In hyperglycemia, glucagon-like peptide-1 (GLP-1) lowers brain glucose concentration together with increased net blood-brain clearance and brain metabolism, but it is not known whether this effect depends on the prevailing plasma glucose (PG) concentration. In hypoglycemia, glucose depletion potentially impairs brain function. Here, we test the hypothesis that GLP-1 exacerbates the effect of hypoglycemia. To test the hypothesis, we determined glucose transport and consumption rates in seven h...

  4. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  5. How can a beta-sheet peptide be both a potent antimicrobial and harmfully toxic? Molecular dynamics simulations of protegrin-1 in micelles

    DEFF Research Database (Denmark)

    Langham, Allison A; Khandelia, Himanshu; Kaznessis, Yiannis N

    2006-01-01

    In this work, the naturally occurring beta-hairpin antimicrobial peptide protegrin-1 (PG-1) is studied by molecular dynamics simulation in all-atom sodium dodecylsulfate and dodecylphosphocholine micelles. These simulations provide a high-resolution picture of the interactions between the peptide...

  6. GLP-1 and exendin-4 for imaging endocrine pancreas. A review. Labelled glucagon-like peptide-1 analogues: past, present and future

    International Nuclear Information System (INIS)

    Hubalewska-Dydejczyk, A.; Sowa-Staszczak, A.; Tomaszuk, M.; Stefańska, A.

    2015-01-01

    Glucagon-like peptide 1 (GLP-1) receptors expression has been found on many types of cancer cells. In case of benign insulinoma the density of those receptors is even higher than the density of somatostatin receptors. This article presents the results of clinical trials proving the utility of GLP-1 receptors imaging. Scintigraphy or positron emission tomography with the use of GLP-1 analogues labelled with appropriate radioisotopes ( 111I n, 99m Tc, 68 Ga, 18 F or 64 Cu) seem to be superior compared with other available techniques in diagnosis of hardly detectable benign insulinoma. While surgery is the only effective therapy for insulinoma patients, therefore proper preoperative localization of the tumor allows sparing operation. Glucagon-like peptide 1 receptors might become also a target for imaging of other tumors such as gastrinoma, pheochromocytoma and medullary thyroid cancer (MTC), which also were shown to over express this type of receptors. However, studies with larger groups of patients are required to prove the clinical usefulness of this indication. Moreover GLP-1 receptor imaging seems to be a potential tool to evaluate pancreatic beta cell mass (BCM). It may be useful in the early diagnosis of beta cell loss in preclinical phases of diabetes. The panceratic beta cells imaging may influence the prophylaxis of diabetes and management of diabetic patients. Presented results of clinical trials prove that glucagon-like peptide 1 receptor imaging might become helpful diagnostic strategy particularly in case of patients with benign insulinoma tumors, but also patients with gastrinoma, pheochromocytoma, medullary thyroid cancer and diabetes.

  7. Ethiopian Pharmaceutical Journal - Vol 23, No 1 (2005)

    African Journals Online (AJOL)

    Antibacterial activity of honey produced by honeybees (Apis mellifera) on bacterial species isolated from infected wound · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Andargachew Mulu, Afework Kassu, Belay Tessema, 1-6. http://dx.doi.org/10.4314/epj.v23i1.35085 ...

  8. Entrapment of Aβ1-40 peptide in unstructured aggregates

    International Nuclear Information System (INIS)

    Corsale, C; Carrotta, R; Mangione, M R; Vilasi, S; Provenzano, A; Bulone, D; San Biagio, P L; Cavallaro, G

    2012-01-01

    Recognizing the complexity of the fibrillogenesis process provides a solid ground for the development of therapeutic strategies aimed at preventing or inhibiting protein-protein aggregation. Under this perspective, it is meaningful to identify the possible aggregation pathways and their relative products. We found that Aβ-peptide dissolved in a pH 7.4 solution at small peptide concentration and low ionic strength forms globular aggregates without typical amyloid β-conformation. ThT binding kinetics was used to monitor aggregate formation. Circular dichroism spectroscopy, AFM imaging, static and dynamic light scattering were used for structural and morphological characterization of the aggregates. They appear stable or at least metastable with respect to fiber growth, therefore appearing as an incidental product in the pathway of fibrillogenesis. (paper)

  9. An UHPLC-MS/MS method for simultaneous quantification of human amyloid beta peptides1-38, Aβ1-40 and Aβ1-42 in cerebrospinal fluid using micro-elution solid phase extraction.

    Science.gov (United States)

    Lin, Ping-Ping; Chen, Wei-Li; Yuan, Fei; Sheng, Lei; Wu, Yu-Jia; Zhang, Wei-Wei; Li, Guo-Qing; Xu, Hong-Rong; Li, Xue-Ning

    2017-12-01

    Amyloid beta (Aβ) peptides in cerebrospinal fluid are extensively estimated for identification of Alzheimer's disease (AD) as diagnostic biomarkers. Unfortunately, their pervasive application is hampered by interference from Aβ propensity of self-aggregation, nonspecifically bind to surfaces and matrix proteins, and by lack of quantitive standardization. Here we report on an alternative Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous measurement of human amyloid beta peptides1-38, Aβ1-40 and Aβ1-42 in cerebrospinal fluid (CSF) using micro-elution solid phase extraction (SPE). Samples were pre-processing by the mixed-mode micro-elution solid phase extraction and quantification was performed in the positive ion multiple reaction monitoring (MRM) mode using electrospray ionization. The stable-isotope labeled Aβ peptides 15 N 51 - Aβ1-38, 15 N 53 - Aβ1-40 and 15 N 55 - Aβ1-42 peptides were used as internal standards. And the artificial cerebrospinal fluid (ACSF) containing 5% rat plasma was used as a surrogate matrix for calibration curves. The quality control (QC) samples at 0.25, 2 and 15ng/mL were prepared. A "linear" regression (1/x 2 weighting): y=ax+b was used to fit the calibration curves over the concentration range of 0.1-20ng/mL for all three peptides. Coefficient of variation (CV) of intra-batch and inter-batch assays were all less than 6.44% for Aβ1-38, 6.75% for Aβ1-40 and 10.74% for Aβ1-42. The precision values for all QC samples of three analytes met the acceptance criteria. Extract recoveries of Aβ1-38, Aβ1-40 and Aβ1-42 were all greater than 70.78%, both in low and high QC samples. The stability assessments showed that QC samples at both low and high levels could be stable for at least 24h at 4°C, 4h at room temperature and through three freeze-thaw cycles without sacrificing accuracy or precision. And no significant carryover effect was observed. This validated UHPLC

  10. Effect of chenodeoxycholic acid and the bile acid sequestrant colesevelam on glucagon-like peptide-1 secretion

    DEFF Research Database (Denmark)

    Hansen, Morten; Scheltema, Matthijs J; Sonne, David P

    2016-01-01

    AIMS: In patients with type 2 diabetes, rectal administration of bile acids increases glucagon-like peptide-1 (GLP-1) secretion and reduces plasma glucose. In addition, oral bile acid sequestrants (BASs) reduce blood glucose by an unknown mechanism. In this study we evaluated the effects...... of the primary human bile acid, chenodeoxycholic acid (CDCA), and the BAS, colesevelam, instilled into the stomach, on plasma levels of GLP-1, glucose-dependent insulinotropic polypeptide, glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin as well as gastric emptying, gallbladder volume, appetite......, and delayed gastric emptying. We speculate that bile acid-induced activation of TGR5 on L cells increases GLP-1 secretion, which in turn may result in amplification of glucose-stimulated insulin secretion. Furthermore our data suggest that colesevelam does not have an acute effect on GLP-1 secretion in humans....

  11. Value of Adjusted Blood Requirement Index in determining failure to control bleed in patients with variceal bleeding.

    Science.gov (United States)

    Abid, Shahab; Khalid, Abdullah B; Awan, Safia; Shah, Hasnain A; Hamid, Saeed; Jafri, Wasim

    2015-03-01

    Variceal bleeding is a serious complication in patients with cirrhosis. Among the criteria that were proposed in Baveno conferences, the Adjusted Blood Requirement Index (ABRI) has not been validated prospectively in clinical practice. We therefore aim to evaluate the measurement of ABRI as a marker of failure to control bleeding and to evaluate the consistency of ABRI in relation to other criteria of failure to control variceal bleeding. All patients with variceal bleeding who presented to Aga Khan University Hospital from January 2010 to December 2012 who were administered transfusion of packed red blood cells were included after obtaining informed consent. All patients were managed as per the standard protocol with intravenous terlipressin along with band ligation and injection of cyanoacrylate in cases of esophageal and fundal varices, respectively. Hemoglobin and hematocrit were measured every 6 h for 48 h and then every 12 h until 5 days of index bleed in each patient. Packed cells were transfused if hemoglobin decreased below 8 g/dl. The number of blood units transfused, change in hemoglobin values, and ABRI were calculated after each unit of blood transfusion till 120 h. In patients in whom bleed could not be controlled, an ABRI value of 0.75 or more was compared with other Baveno IV-based parameters that define failure to control variceal bleeding. During the study period, 137 eligible patients with variceal bleed were admitted. The mean age of the patients was 52±12 years. The majority of patients (50.4%) were in Child-Pugh class B, followed by 38% in Child-Pugh class C. According to the Baveno IV criteria, overall failure to control acute variceal bleeding occurred in 52 (37.9%) patients. Excluding ABRI, failure to control bleeding was found in 22/137 (16%) patients, whereas ABRI-based criteria showed that in 34/137 (24.8%) patients, bleeding could not be controlled. There were only four (2.9%) patients with variceal bleeding in whom ABRI and

  12. Peripherally applied synthetic peptide isoAsp7-Aβ(1-42) triggers cerebral β-amyloidosis.

    Science.gov (United States)

    Kozin, S A; Cheglakov, I B; Ovsepyan, A A; Telegin, G B; Tsvetkov, P O; Lisitsa, A V; Makarov, A A

    2013-10-01

    Intracerebral and intraperitoneal inoculation with β-amyloid-rich brain extracts originating from patients with Alzheimer's disease as well as intracerebral injection of aggregates composed of synthetic Aβ can induce cerebral β-amyloidosis, and associated cognitive dysfunctions in susceptible animal hosts. We have found that repetitive intravenous administration of 100 μg of synthetic peptide corresponding to isoAsp7-containing Aβ(1-42), an abundant age-dependent Aβ isoform present both in the pathological brain and in synthetic Aβ preparations, robustly accelerates formation of classic dense-core congophilic amyloid plaques in the brain of β-amyloid precursor protein transgenic mice. Our findings indicate this peptide as an inductive agent of cerebral β-amyloidosis in vivo.

  13. Neoglycolipids for Prolonging the Effects of Peptides

    DEFF Research Database (Denmark)

    van Witteloostuijn, Søren Blok; Mannerstedt, Karin Margareta Sophia; Wismann, Pernille

    2017-01-01

    Novel principles for optimizing the properties of peptide-based drugs are needed in order to leverage their full pharmacological potential. We present the design, synthesis, and evaluation of a library of neoglycolipidated glucagon-like peptide 1 (GLP-1) analogues, which are valuable drug...... was maintained or even improved compared to native GLP-1. This translated into pronounced in vivo efficacy in terms of both decreased acute food intake and improved glucose homeostasis in mice. Thus, we propose neoglycolipidation as a novel, general method for modulating the properties of therapeutic peptides...

  14. Corn Silk Extract and Its Bioactive Peptide Ameliorated Lipopolysaccharide-Induced Inflammation in Mice via the Nuclear Factor-κB Signaling Pathway.

    Science.gov (United States)

    Ho, Tin-Yun; Li, Chia-Cheng; Lo, Hsin-Yi; Chen, Feng-Yuan; Hsiang, Chien-Yun

    2017-02-01

    Bioactive peptides derived from foods have shown beneficial anti-inflammatory potential. Inhibitory κB kinase-β (IKKβ) plays a crucial role in the activation of nuclear factor-κB (NF-κB), a transcription factor involved in inflammation. Here we applied proteomic and bioinformatics approaches to identify anti-inflammatory peptides that target IKKβ from corn silk. Corn silk extract significantly suppressed lipopolysaccharide (LPS)-induced NF-κB activities [(1.7 ± 0.2)-fold vs (3.0 ± 0.6)-fold, p corn silk also suppressed LPS-induced NF-κB activities [(1.1 ± 0.3)-fold vs 3.3 ± 0.5 fold, p corn silk extract and trypsin hydrolysate significantly inhibited LPS-induced interleukin-1β (IL-1β) production by 58.3 ± 4.5 and 55.1 ± 7.4%, respectively. A novel peptide, FK2, docked into the ATP-binding pocket of IKKβ, was further identified from trypsin hydrolysis of corn silk. FK2 inhibited IKKβ activities, IκB phosphorylation, and subsequent NF-κB activation [(2.3 ± 0.4)-fold vs (5.5 ± 0.4)-fold, p corn silk displayed anti-inflammatory abilities. In addition, we first identified an anti-inflammatory peptide FK2 from corn silk. Moreover, the anti-inflammatory effect of FK2 might be through IKKβ-NF-κB signaling pathways.

  15. Peptides Interfering 3A Protein Dimerization Decrease FMDV Multiplication.

    Directory of Open Access Journals (Sweden)

    Mónica González-Magaldi

    Full Text Available Nonstructural protein 3A is involved in relevant functions in foot-and-mouth disease virus (FMDV replication. FMDV 3A can form homodimers and preservation of the two hydrophobic α-helices (α1 and α2 that stabilize the dimer interface is essential for virus replication. In this work, small peptides mimicking residues involved in the dimer interface were used to interfere with dimerization and thus gain insight on its biological function. The dimer interface peptides α1, α2 and that spanning the two hydrophobic α-helices, α12, impaired in vitro dimer formation of a peptide containing the two α-helices, this effect being higher with peptide α12. To assess the effect of dimer inhibition in cultured cells, the interfering peptides were N-terminally fused to a heptaarginine (R7 sequence to favor their intracellular translocation. Thus, when fused to R7, interference peptides (100 μM were able to inhibit dimerization of transiently expressed 3A, the higher inhibitions being found with peptides α1 and α12. The 3A dimerization impairment exerted by the peptides correlated with significant, specific reductions in the viral yield recovered from peptide-treated FMDV infected cells. In this case, α2 was the only peptide producing significant reductions at concentrations lower than 100 μM. Thus, dimer interface peptides constitute a tool to understand the structure-function relationship of this viral protein and point to 3A dimerization as a potential antiviral target.

  16. Mixed Fibronectin-Derived Peptides Conjugated to a Chitosan Matrix Effectively Promotes Biological Activities through Integrins, α4β1, α5β1, αvβ3, and Syndecan

    Directory of Open Access Journals (Sweden)

    Hozumi Kentaro

    2016-11-01

    Full Text Available Mimicking the biological function of the extracellular matrix is an approach to developing cell adhesive biomaterials. The RGD peptide, derived from fibronectin (Fn, mainly binds to integrin αvβ3 and has been widely used as a cell adhesive peptide on various biomaterials. However, cell adhesion to Fn is thought to be mediated by several integrin subtypes and syndecans. In this study, we synthesized an RGD-containing peptide (FIB1 and four integrin α4β1-binding-related motif-containing peptides (LDV, IDAPS, KLDAPT, and PRARI and constructed peptide-chitosan matrices. The FIB1-chitosan matrix promoted human dermal fibroblast (HDF attachment, and the C-terminal elongated PRARI (ePRARI-C-conjugated chitosan matrix significantly promoted HDF attachment through integrin α4β1 and syndecan binding. Next, we constructed a mixed ePRARI-C- and FIB1-chitosan matrix to develop a Fn mimetic biomaterial. The mixed ePRARI-C/FIB1-chitosan matrix promoted significantly better cell attachment and neurite outgrowth compared to those of either ePRARI-C- or FIB1-chitosan matrices. HDF adhesion to the ePRARI-C/FIB1-chitosan matrix was mediated by integrin, α4β1, α5β1, and αvβ3, similar to HDF adhesion to Fn. These data suggest that an ePRARI-C/FIB1-chitosan matrix can be used as a tool to analyze the multiple functions of Fn and can serve as a Fn-mimetic biomaterial.

  17. Mathematical Modelling of Glucose-Dependent Insulinotropic Polypeptide and Glucagon-like Peptide-1 following Ingestion of Glucose

    DEFF Research Database (Denmark)

    Røge, Rikke M; Bagger, Jonatan I; Alskär, Oskar

    2017-01-01

    The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), play an important role in glucose homeostasis by potentiating glucose-induced insulin secretion. Furthermore, GLP-1 has been reported to play a role in glucose homeostasis by inhibiting ...

  18. Primary and secondary structure dependence of peptide flexibility assessed by fluorescence-based measurement of end-to-end collision rates.

    Science.gov (United States)

    Huang, Fang; Hudgins, Robert R; Nau, Werner M

    2004-12-22

    The intrachain fluorescence quenching of the fluorophore 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) is measured in short peptide fragments, namely the two strands and the turn of the N-terminal beta-hairpin of ubiquitin. The investigated peptides adopt a random-coil conformation in aqueous solution according to CD and NMR experiments. The combination of quenchers with different quenching efficiencies, namely tryptophan and tyrosine, allows the extrapolation of the rate constants for end-to-end collision rates as well as the dissociation of the end-to-end encounter complex. The measured activation energies for fluorescence quenching demonstrate that the end-to-end collision process in peptides is partially controlled by internal friction within the backbone, while measurements in solvents of different viscosities (H2O, D2O, and 7.0 M guanidinium chloride) suggest that solvent friction is an additional important factor in determining the collision rate. The extrapolated end-to-end collision rates, which are only slightly larger than the experimental rates for the DBO/Trp probe/quencher system, provide a measure of the conformational flexibility of the peptide backbone. The chain flexibility is found to be strongly dependent on the type of secondary structure that the peptides represent. The collision rates for peptides derived from the beta-strand motifs (ca. 1 x 10(7) s(-1)) are ca. 4 times slower than that derived from the beta-turn. The results provide further support for the hypothesis that chain flexibility is an important factor in the preorganization of protein fragments during protein folding. Mutations to the beta-turn peptide show that subtle sequence changes strongly affect the flexibility of peptides as well. The protonation and charge status of the peptides, however, are shown to have no significant effect on the flexibility of the investigated peptides. The meaning and definition of end-to-end collision rates in the context of protein folding are critically

  19. Diagnostic performance of Baveno IV criteria in cirrhotic patients with upper gastrointestinal bleeding: analysis of the F7 liver-1288 study population

    DEFF Research Database (Denmark)

    Thabut, D; D'Amico, G; Tan, P

    2010-01-01

    The definition of failure to control bleeding agreed upon at the Baveno IV consensus meeting, included the Adjusted Blood Requirement Index [ABRI: number of blood units/(final-initial hematocrit+0.01)]. ABRI =0.75 denotes failure. However, timing for hematocrit measurements was not defined....... The aims of this study were: (1) to assess the Baveno IV criteria performance to classify treatment success or failure to control bleeding at 5 days, (2) to determine the appropriate timing for hematocrit....

  20. Diagnostic performance of Baveno IV criteria in cirrhotic patients with upper gastrointestinal bleeding: analysis of the F7 liver-1288 study population

    DEFF Research Database (Denmark)

    Thabut, D; D'Amico, G; Tan, P

    2010-01-01

    The definition of failure to control bleeding agreed upon at the Baveno IV consensus meeting, included the Adjusted Blood Requirement Index [ABRI: number of blood units/(final-initial hematocrit+0.01)]. ABRI ≥0.75 denotes failure. However, timing for hematocrit measurements was not defined....... The aims of this study were: (1) to assess the Baveno IV criteria performance to classify treatment success or failure to control bleeding at 5 days, (2) to determine the appropriate timing for hematocrit....

  1. Glucagon-like peptide-1 receptor overexpression in cancer and its impact on clinical applications

    Directory of Open Access Journals (Sweden)

    Meike eKörner

    2012-12-01

    Full Text Available Peptide hormones of the glucagon-like peptide (GLP family play an increasing clinical role, such as GLP-1 in diabetes therapy. Moreover, GLP receptors are over-expressed in various human tumor types and therefore represent molecular targets for important clinical applications. In particular, virtually all benign insulinomas highly over-express GLP-1 receptors (GLP-1R. Targeting GLP-1R with the stable GLP-1 analogs 111In-DOTA/ DPTA-exendin-4 offers a new approach to successfully localize these small tumors. This non-invasive technique has the potential to replace the invasive localization of insulinomas by selective arterial stimulation and venous sampling. Malignant insulinomas, in contrast to their benign counterparts, express GLP-1R in only one third of the cases, while they more often express the somatostatin type 2 receptors. Importantly, one of the two receptors appears to be always expressed in malignant insulinomas. The GLP-1R overexpression in selected cancers is worth to be kept in mind with regard to the increasing use of GLP-1 analogs for diabetes therapy. While the functional role of GLP-1R in neoplasia is not known yet, it may be safe to monitore patients undergoing GLP-1 therapy carefully.

  2. TIA-1 RRM23 binding and recognition of target oligonucleotides.

    Science.gov (United States)

    Waris, Saboora; García-Mauriño, Sofía M; Sivakumaran, Andrew; Beckham, Simone A; Loughlin, Fionna E; Gorospe, Myriam; Díaz-Moreno, Irene; Wilce, Matthew C J; Wilce, Jacqueline A

    2017-05-05

    TIA-1 (T-cell restricted intracellular antigen-1) is an RNA-binding protein involved in splicing and translational repression. It mainly interacts with RNA via its second and third RNA recognition motifs (RRMs), with specificity for U-rich sequences directed by RRM2. It has recently been shown that RRM3 also contributes to binding, with preferential binding for C-rich sequences. Here we designed UC-rich and CU-rich 10-nt sequences for engagement of both RRM2 and RRM3 and demonstrated that the TIA-1 RRM23 construct preferentially binds the UC-rich RNA ligand (5΄-UUUUUACUCC-3΄). Interestingly, this binding depends on the presence of Lys274 that is C-terminal to RRM3 and binding to equivalent DNA sequences occurs with similar affinity. Small-angle X-ray scattering was used to demonstrate that, upon complex formation with target RNA or DNA, TIA-1 RRM23 adopts a compact structure, showing that both RRMs engage with the target 10-nt sequences to form the complex. We also report the crystal structure of TIA-1 RRM2 in complex with DNA to 2.3 Å resolution providing the first atomic resolution structure of any TIA protein RRM in complex with oligonucleotide. Together our data support a specific mode of TIA-1 RRM23 interaction with target oligonucleotides consistent with the role of TIA-1 in binding RNA to regulate gene expression. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  4. Effects of subcutaneous glucagon-like peptide 1 (GLP-1 [7-36 amide]) in patients with NIDDM

    DEFF Research Database (Denmark)

    Nauck, M A; Wollschläger, D; Werner, J

    1996-01-01

    with the indicator-dilution method and phenol red. Repeated measures ANOVA was used for statistical analysis. GLP-1 injection led to a short-lived increment in GLP-1 concentrations (peak at 30-60 min, then return to basal levels after 90-120 min). Each GLP-1 injection stimulated insulin (insulin, C-peptide, p ....0001, respectively) and inhibited glucagon secretion (p ... emptying for 30-45 min (p statistically different from placebo) followed by emptying at a normal rate. As a consequence, integrated incremental glucose responses were reduced by 40% (p = 0.051). In conclusion, subcutaneous GLP-1 [7-36 amide] has similar effects in NIDDM patients as an intravenous...

  5. Development and use of engineered peptide deformylase in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia

    2012-01-01

    Deze thesis beschrijft het onderzoek naar potentieel van het gebruik van het peptide deformylase (PDF) in chemo enzymatische peptide synthese. PDF is geschikt voor selective N terminale deformylatie van bepaalde N-formyl-peptides zonder gelijktijdige hydrolyse van de peptide binding. Door de

  6. Bioactivity of a modified human Glucagon-like peptide-1.

    Directory of Open Access Journals (Sweden)

    Fangfang Xu

    Full Text Available Diabetes has become the third largest cause of death in humans worldwide. Therefore, effective treatment for this disease remains a critical issue. Glucagon-like peptide-1 (GLP-1 plays an important role in glucose homeostasis, and therefore represents a promising candidate to use for the treatment of diabetes. Native GLP-1, however, is quickly degraded in in the circulatory system; which limits its clinical application. In the present study, a chemically-synthesized, modified analogue of human GLP-1 (mGLP-1 was designed. Our analyses indicated that, relative to native GLP-1, mGLP-1 is more resistant to trypsin and pancreatin degradation. mGLP-1 promotes mouse pancreatic β-cell proliferation by up-regulating the expression level of cyclin E, CDK2, Bcl-2 and down-regulating Bax, p21, and stimulates insulin secretion. An oral glucose tolerance test indicated that mGLP-1 significantly improved glucose tolerance in mice. Intraperitoneal injections of mGLP-1 into streptozotocin (STZ-induced type 2 diabetic mice significantly reduced blood sugar levels and stimulated insulin secretion. Oral gavages of mGLP-1 in diabetic mice did not result in significant hypoglycemic activity.

  7. Real-time trafficking and signaling of the glucagon-like peptide-1 receptor

    DEFF Research Database (Denmark)

    Roed, Sarah Noerklit; Wismann, Pernille; Underwood, Christina Rye

    2014-01-01

    The glucagon-like peptide-1 incretin receptor (GLP-1R) of family B G protein-coupled receptors (GPCRs) is a major drug target in type-2-diabetes due to its regulatory effect on post-prandial blood-glucose levels. The mechanism(s) controlling GLP-1R mediated signaling are far from fully understood....... A fundamental mechanism controlling the signaling capacity of GPCRs is the post-endocytic trafficking of receptors between recycling and degradative fates. Here, we combined microscopy with novel real-time assays to monitor both receptor trafficking and signaling in living cells. We find that the human GLP-1R...

  8. Folding Topology of a Short Coiled-Coil Peptide Structure Templated by an Oligonucleotide Triplex

    DEFF Research Database (Denmark)

    Lou, Chenguang; Christensen, Niels Johan; Martos Maldonado, Manuel Cristo

    2017-01-01

    by oligonucleotide duplex and triplex formation. POC synthesis was achieved by copper-free alkyne-azide cycloaddition between three oligonucleotides and a 23-mer peptide, which by itself exhibited multiple oligomeric states in solution. The oligonucleotide domain was designed to furnish a stable parallel triplex......, small-angle X-ray scattering (SAXS), and molecular modeling. Stabilizing cooperativity was observed between the trimeric peptide and the oligonucleotide triplex domains, and the overall molecular size (ca. 12nm) in solution was revealed to be independent of concentration. The topological folding...

  9. Self-assembly of fibronectin mimetic peptide-amphiphile nanofibers

    Science.gov (United States)

    Rexeisen, Emilie Lynn

    Many therapeutic strategies incorporate peptides into their designs to mimic the natural protein ligands found in vivo. A few examples are the short peptide sequences RGD and PHSRN that mimic the primary and synergy-binding domains of the extracellular matrix protein, fibronectin, which is recognized by the cell surface receptor, alpha5beta 1 integrin. Even though scaffold modification with biomimetic peptides remains one of the most promising approaches for tissue engineering, the use of these peptides in therapeutic tissue-engineered products and drug delivery systems available on the commercial market is limited because the peptides are not easily able to mimic the natural protein. The design of a peptide that can effectively target the alpha5beta1 integrin would greatly increase biomimetic scaffold therapeutic potential. A novel peptide containing both the RGD primary binding domain and PHSRN synergy-binding domain for fibronectin joined with the appropriate linker should bind alpha 5beta1 integrin more efficiently and lead to greater cell adhesion over RGD alone. Several fibronectin mimetic peptides were designed and coupled to dialkyl hydrocarbon tails to make peptide-amphiphiles. The peptides contained different linkers connecting the two binding domains and different spacers separating the hydrophobic tails from the hydrophilic headgroups. The peptide-amphiphiles were deposited on mica substrates using the Langmuir-Blodgett technique. Langmuir isotherms indicated that the peptide-amphiphiles that contained higher numbers of serine residues formed a more tightly packed monolayer, but the increased number of serines also made transferring the amphiphiles to the mica substrate more difficult. Atomic force microscopy (AFM) images of the bilayers showed that the headgroups might be bent, forming small divots in the surface. These divots may help expose the PHSRN synergy-binding domain. Parallel studies undertaken by fellow group members showed that human

  10. Novel Antimicrobial Peptides EeCentrocins 1, 2 and EeStrongylocin 2 from the Edible Sea Urchin Echinus esculentus Have 6-Br-Trp Post-Translational Modifications.

    Directory of Open Access Journals (Sweden)

    Runar Gjerp Solstad

    Full Text Available The global problem of microbial resistance to antibiotics has resulted in an urgent need to develop new antimicrobial agents. Natural antimicrobial peptides are considered promising candidates for drug development. Echinoderms, which rely on innate immunity factors in the defence against harmful microorganisms, are sources of novel antimicrobial peptides. This study aimed to isolate and characterise antimicrobial peptides from the Edible sea urchin Echinus esculentus. Using bioassay-guided purification and cDNA cloning, three antimicrobial peptides were characterised from the haemocytes of the sea urchin; two heterodimeric peptides and a cysteine-rich peptide. The peptides were named EeCentrocin 1 and 2 and EeStrongylocin 2, respectively, due to their apparent homology to the published centrocins and strongylocins isolated from the green sea urchin Strongylocentrotus droebachiensis. The two centrocin-like peptides EeCentrocin 1 and 2 are intramolecularly connected via a disulphide bond to form a heterodimeric structure, containing a cationic heavy chain of 30 and 32 amino acids and a light chain of 13 amino acids. Additionally, the light chain of EeCentrocin 2 seems to be N-terminally blocked by a pyroglutamic acid residue. The heavy chains of EeCentrocins 1 and 2 were synthesised and shown to be responsible for the antimicrobial activity of the natural peptides. EeStrongylocin 2 contains 6 cysteines engaged in 3 disulphide bonds. A fourth peptide (Ee4635 was also discovered but not fully characterised. Using mass spectrometric and NMR analyses, EeCentrocins 1 and 2, EeStrongylocin 2 and Ee4635 were all shown to contain post-translationally brominated Trp residues in the 6 position of the indole ring.

  11. Synthesis and evaluation of amphiphilic peptides as nanostructures and drug delivery tools

    Science.gov (United States)

    Sayeh, Naser Ali

    us to explore requirements for generating peptides with optimized drug encapsulation and to establish correlations between the structure of peptides with their drug entrapment properties. Thus, the general objective of this dissertation was to design and evaluate additional cyclic or amphiphilic peptides as nanostructures, compare their efficiency in delivery of small molecules with the previously reported cyclic peptides containing tryptophan and arginine residues. This dissertation consists of three chapters. Chapter 1. MANUSCRIPT (published in Current Organic Chemistry 2014). The objective of this work was to design amphiphilic linear and cyclic peptides containing hydrophobic tryptophan W residues that were linked through a triazole ring to positively charged arginine R and lysine (K) residues. The peptides were synthesized through click chemistry between hydrophobic peptides containing alkyne and positively charged peptides containing azide groups. Characterization of their structures like solubility, CD, TEM, cytotoxicity were investigated. The conjugates were showed minimal cytotoxicity at two cell lines. The secondary structures of both peptides were similar to a distorted α-helix as shown by CD spectroscopy. TEM imaging also showed that linear-linear (WG(triazole-KR-NH2))3 and cyclic-linear [WG(triazole-KR-NH2)]3 peptides formed nano-sized structures. Chapter 2. MANUSCRIPT I (Submitted to Journal of Molecular Modeling). In this work, we investigated the structural and dynamical aspects of cyclic-linear peptide ([WG(triazole-KR-NH2)] 3 and linear-linear peptide (WG(triazole-KR-NH2))3) formed nanostructures compared to a drug delivery system with [WR]4. While [WR]4 was found to be an efficient molecular transporter for small molecule drugs, such as lamivudine and dasatinib, cyclic-linear peptide ([WG(triazole-KR-NH2)]3 was inefficient. Molecular modeling was used to explain the differential behavior of these peptides. We showed how the morphology of these

  12. Expression of a novel antimicrobial peptide Penaeidin4-1 in creeping bentgrass (Agrostis stolonifera L. enhances plant fungal disease resistance.

    Directory of Open Access Journals (Sweden)

    Man Zhou

    Full Text Available BACKGROUND: Turfgrass species are agriculturally and economically important perennial crops. Turfgrass species are highly susceptible to a wide range of fungal pathogens. Dollar spot and brown patch, two important diseases caused by fungal pathogens Sclerotinia homoecarpa and Rhizoctonia solani, respectively, are among the most severe turfgrass diseases. Currently, turf fungal disease control mainly relies on fungicide treatments, which raises many concerns for human health and the environment. Antimicrobial peptides found in various organisms play an important role in innate immune response. METHODOLOGY/PRINCIPAL FINDINGS: The antimicrobial peptide - Penaeidin4-1 (Pen4-1 from the shrimp, Litopenaeus setiferus has been reported to possess in vitro antifungal and antibacterial activities against various economically important fungal and bacterial pathogens. In this study, we have studied the feasibility of using this novel peptide for engineering enhanced disease resistance into creeping bentgrass plants (Agrostis stolonifera L., cv. Penn A-4. Two DNA constructs were prepared containing either the coding sequence of a single peptide, Pen4-1 or the DNA sequence coding for the transit signal peptide of the secreted tobacco AP24 protein translationally fused to the Pen4-1 coding sequence. A maize ubiquitin promoter was used in both constructs to drive gene expression. Transgenic turfgrass plants containing different DNA constructs were generated by Agrobacterium-mediated transformation and analyzed for transgene insertion and expression. In replicated in vitro and in vivo experiments under controlled environments, transgenic plants exhibited significantly enhanced resistance to dollar spot and brown patch, the two major fungal diseases in turfgrass. The targeting of Pen4-1 to endoplasmic reticulum by the transit peptide of AP24 protein did not significantly impact disease resistance in transgenic plants. CONCLUSION/SIGNIFICANCE: Our results

  13. New dendrimer - Peptide host - Guest complexes: Towards dendrimers as peptide carriers

    DEFF Research Database (Denmark)

    Boas, Ulrik; Sontjens, S.H.M.; Jensen, Knud Jørgen

    2002-01-01

    Adamantyl urea and adamantyl thiourea modified poly(propylene imine) dendrimers act as hosts for N-terminal tert-butoxycarbonyl (Boc)-protected peptides and form chloroform-soluble complexes. investigations with NMR spectroscopy show that the peptide is bound to the dendrimer by ionic interactions...... between the dendrimer outer shell tertiary amines and the C-terminal carboxylic acid of the peptide, and also through host-urea to peptide-amide hydrogen bonding. The hydrogen-bonding nature of the peptide dendrimer interactions was further confirmed by using Fourier transform IR spectroscopy, for which...... the NH- and CO-stretch signals of the peptide amide moieties shift towards lower wave-numbers upon complexation with the dendrimer. Spatial analysis of the complexes with NOESY spectroscopy generally shows close proximity of the N-terminal Boc group of the peptide to the peripheral adamantyl groups...

  14. The glucagon-like peptide-1 metabolite GLP-1-(9-36) amide reduces postprandial glycemia independently of gastric emptying and insulin secretion in humans

    DEFF Research Database (Denmark)

    Meier, Juris J; Gethmann, Arnica; Nauck, Michael A

    2006-01-01

    Glucagon-like peptide 1 (GLP-1) lowers glycemia by modulating gastric emptying and endocrine pancreatic secretion. Rapidly after its secretion, GLP-1-(7-36) amide is degraded to the metabolite GLP-1-(9-36) amide. The effects of GLP-1-(9-36) amide in humans are less well characterized. Fourteen...... healthy volunteers were studied with intravenous infusion of GLP-1-(7-36) amide, GLP-1-(9-36) amide, or placebo over 390 min. After 30 min, a solid test meal was served, and gastric emptying was assessed. Blood was drawn for GLP-1 (total and intact), glucose, insulin, C-peptide, and glucagon measurements....... Administration of GLP-1-(7-36) amide and GLP-1-(9-36) amide significantly raised total GLP-1 plasma levels. Plasma concentrations of intact GLP-1 increased to 21 +/- 5 pmol/l during the infusion of GLP-1-(7-36) amide but remained unchanged during GLP-1-(9-36) amide infusion [5 +/- 3 pmol/l; P

  15. Multi-structure docking analysis of BACE1 crystal structures and non-peptidic ligands.

    Science.gov (United States)

    Haghighijoo, Zahra; Hemmateenejad, Bahram; Edraki, Najmeh; Miri, Ramin; Emami, Saeed

    2017-09-01

    In order to design novel non-peptidic inhibitors of BACE1, many research groups have attempted using computational studies including docking analyses. Since there are too many 3D structures for BACE1 in the protein database, the selection of suitable crystal structures is a key prerequisite for the successful application of molecular docking. We employed a multi-structure docking protocol. In which 615 ligands' structures were docked into 150 BACE1 structures. The large number of the resultant docking scores were post-processed by different data analysis methods including exploratory data analysis, regression analysis and discriminant analysis. It was found that using one crystal structure for docking did not result in high accuracy for predicting activity of the BACE1 inhibitors. Instead, using of the multi-structural docking scores, post-processed by chemometrics methods arrived to highly accurate predictive models. In this regards, the PDB accession codes of 4B70, 4DVF and 2WEZ could discriminate between active and inactive compounds, with higher accuracy. Clustering of the BACE1 structures based on principal component analysis of the crystallographic structures the revealed that the discriminant structures are in the center of the clusters. Thus, these structures can be selected as predominant crystal structures for docking studies of non-peptidic BACE1 inhibitors. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Cox1 mutation abrogates need for Cox23 in cytochrome c oxidase biogenesis

    Directory of Open Access Journals (Sweden)

    Richard Dela Cruz

    2016-06-01

    Full Text Available Cox23 is a known conserved assembly factor for cytochrome c oxidase, although its role in cytochrome c oxidase (CcO biogenesis remains unresolved. To gain additional insights into its role, we isolated spontaneous suppressors of the respiratory growth defect in cox23∆ yeast cells. We recovered independent colonies that propagated on glycerol/lactate medium for cox23∆ cells at 37°C. We mapped these mutations to the mitochondrial genome and specifically to COX1 yielding an I101F substitution. The I101F Cox1 allele is a gain-of-function mutation enabling yeast to respire in the absence of Cox23. CcO subunit steady-state levels were restored with the I101F Cox1 suppressor mutation and oxygen consumption and CcO activity were likewise restored. Cells harboring the mitochondrial genome encoding I101F Cox1 were used to delete genes for other CcO assembly factors to test the specificity of the Cox1 mutation as a suppressor of cox23∆ cells. The Cox1 mutant allele fails to support respiratory growth in yeast lacking Cox17, Cox19, Coa1, Coa2, Cox14 or Shy1, demonstrating its specific suppressor activity for cox23∆ cells.

  17. de Thymus fontanesii Boiss & Reut

    African Journals Online (AJOL)

    AKA BOKO

    Les huiles essentielles sont conservées à 4°C et à l'abri de la lumière. 2-3. Analyse physicochimique de l'huile essentielle du. Thymus fontanesii. Ces analyses sont faites en conformité aux normes A.F.N.O.R [4] Nous avons déterminé les: Caractères physiques : densité, indice de réfraction, pouvoir rotatoire, solubilité dans.

  18. Penetration of polymeric nanoparticles loaded with an HIV-1 inhibitor peptide derived from GB virus C in a vaginal mucosa model.

    Science.gov (United States)

    Ariza-Sáenz, Martha; Espina, Marta; Bolaños, Nuria; Calpena, Ana Cristina; Gomara, María José; Haro, Isabel; García, María Luisa

    2017-11-01

    Despite the great effort to decrease the HIV infectivity rate, current antiretroviral therapy has several weaknesses; poor bioavailability, development of drug resistance and poor ability to access tissues. However, molecules such as peptides have emerged asa new expectative to HIV eradication. The vaginal mucosa is the main spreading point of HIV. There are natural barriers such as the vaginal fluid which protects the vaginal epithelium from any foreign agents reaching it. This work has developed and characterized Nanoparticles (NPs) coated with glycol chitosan (GC), loaded with an HIV-1 inhibitor peptide (E2). In vitro release and ex vivo studies were carried out using the vaginal mucosa of swine and the peptide was determined by HPLC MS/MS validated method. Moreover, the peptide was labeled with 5(6)-carboxyfluoresceine and entrapped into the NPs to carried out in vivo studies and to evaluate the NPs penetration and toxicity in the vaginal mucosa of the swine. The mean size of the NPs, ξ and the loading percentage were fundamental features for to reach the vaginal tissue and to release the peptide within intercellular space. The obtained results suggesting that the fusion inhibitor peptides loaded into the NPs coated with GC might be a new way to fight the HIV-1, due to the formulation might reach the human epithelial mucosa and release peptide without any side effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The Equine Antimicrobial Peptide eCATH1 Is Effective against the Facultative Intracellular Pathogen Rhodococcus equi in Mice

    Science.gov (United States)

    Schlusselhuber, Margot; Torelli, Riccardo; Martini, Cecilia; Leippe, Matthias; Cattoir, Vincent; Leclercq, Roland; Laugier, Claire; Grötzinger, Joachim; Sanguinetti, Maurizio

    2013-01-01

    Rhodococcus equi, the causal agent of rhodococcosis, is a major pathogen of foals and is also responsible for severe infections in immunocompromised humans. Of great concern, strains resistant to currently used antibiotics have emerged. As the number of drugs that are efficient in vivo is limited because of the intracellular localization of the bacterium inside macrophages, new active but cell-permeant drugs will be needed in the near future. In the present study, we evaluated, by in vitro and ex vivo experiments, the ability of the alpha-helical equine antimicrobial peptide eCATH1 to kill intracellular bacterial cells. Moreover, the therapeutic potential of the peptide was assessed in experimental rhodococcosis induced in mice, while the in vivo toxicity was evaluated by behavioral and histopathological analysis. The study revealed that eCATH1 significantly reduced the number of bacteria inside macrophages. Furthermore, the bactericidal potential of the peptide was maintained in vivo at doses that appeared to have no visible deleterious effects for the mice even after 7 days of treatment. Indeed, daily subcutaneous injections of 1 mg/kg body weight of eCATH1 led to a significant reduction of the bacterial load in organs comparable to that obtained after treatment with 10 mg/kg body weight of rifampin. Interestingly, the combination of the peptide with rifampin showed a synergistic interaction in both ex vivo and in vivo experiments. These results emphasize the therapeutic potential that eCATH1 represents in the treatment of rhodococcosis. PMID:23817377

  20. Crystal structure of glucagon-like peptide-1 in complex with the extracellular domain of the glucagon-like peptide-1 receptor.

    Science.gov (United States)

    Underwood, Christina Rye; Garibay, Patrick; Knudsen, Lotte Bjerre; Hastrup, Sven; Peters, Günther H; Rudolph, Rainer; Reedtz-Runge, Steffen

    2010-01-01

    GLP-1 (glucagon-like peptide-1) is an incretin released from intestinal L-cells in response to food intake. Activation of the GLP-1 receptor potentiates the synthesis and release of insulin from pancreatic beta-cells in a glucose-dependent manner. The GLP-1 receptor belongs to class B of the G-protein-coupled receptors, a subfamily characterized by a large N-terminal extracellular ligand binding domain. Exendin-4 and GLP-1 are 50% identical, and exendin-4 is a full agonist with similar affinity and potency for the GLP-1 receptor. We recently solved the crystal structure of the GLP-1 receptor extracellular domain in complex with the competitive antagonist exendin-4(9-39). Interestingly, the isolated extracellular domain binds exendin-4 with much higher affinity than the endogenous agonist GLP-1. Here, we have solved the crystal structure of the extracellular domain in complex with GLP-1 to 2.1 Aresolution. The structure shows that important hydrophobic ligand-receptor interactions are conserved in agonist- and antagonist-bound forms of the extracellular domain, but certain residues in the ligand-binding site adopt a GLP-1-specific conformation. GLP-1 is a kinked but continuous alpha-helix from Thr(13) to Val(33) when bound to the extracellular domain. We supplemented the crystal structure with site-directed mutagenesis to link the structural information of the isolated extracellular domain with the binding properties of the full-length receptor. The data support the existence of differences in the binding modes of GLP-1 and exendin-4 on the full-length GLP-1 receptor.

  1. A glucagon-like peptide-1 receptor agonist reduces intracranial pressure in a rat model of hydrocephalus

    DEFF Research Database (Denmark)

    Botfield, Hannah F; Uldall, Maria S; Westgate, Connar S J

    2017-01-01

    Current therapies for reducing raised intracranial pressure (ICP) under conditions such as idiopathic intracranial hypertension or hydrocephalus have limited efficacy and tolerability. Thus, there is a pressing need to identify alternative drugs. Glucagon-like peptide-1 receptor (GLP-1R) agonists...

  2. FGF23 inhibits extra-renal synthesis of 1,25-dihydroxyvitamin D in human monocytes

    Science.gov (United States)

    Bacchetta, Justine; Sea, Jessica L; Chun, Rene F; Lisse, Thomas S; Wesseling-Perry, Katherine; Gales, Barbara; Adams, John S.; Salusky, Isidro B; Hewison, Martin

    2012-01-01

    Vitamin D is a potent stimulator of monocyte innate immunity, with this effect being mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)2D). In the kidney synthesis of 1,25(OH)2D is suppressed by fibroblast growth factor 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)2D. Monocytes from healthy donor peripheral blood mononuclear cells (PBMCm) and from peritoneal dialysate effluent from kidney disease patients (PDm) were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed co-expression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated MAP kinase (MAPK) and Akt pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)2D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-15 to stimulate synthesis of 1,25(OH)2D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)2D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with CKD. PMID:22886720

  3. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  4. De-novo design of antimicrobial peptides for plant protection.

    Directory of Open Access Journals (Sweden)

    Benjamin Zeitler

    Full Text Available This work describes the de-novo design of peptides that inhibit a broad range of plant pathogens. Four structurally different groups of peptides were developed that differ in size and position of their charged and hydrophobic clusters and were assayed for their ability to inhibit bacterial growth and fungal spore germination. Several peptides are highly active at concentrations between 0,1 and 1 µg/ml against plant pathogenic bacteria, such as Pseudomonas syringae, Pectobacterium carotovorum, and Xanthomonas vesicatoria. Importantly, no hemolytic activity could be detected for these peptides at concentrations up to 200 µg/ml. Moreover, the peptides are also active after spraying on the plant surface demonstrating a possible way of application. In sum, our designed peptides represent new antimicrobial agents and with the increasing demand for antimicrobial compounds for production of "healthy" food, these peptides might serve as templates for novel antibacterial and antifungal agents.

  5. Glucagon-like peptide-2, but not glucose-dependent insulinotropic polypeptide, stimulates glucagon release in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Christensen, Mikkel; Knop, Filip K; Vilsbøll, Tina

    2010-01-01

    This study investigated the glucagon-releasing properties of the hormones glucagon-like peptide-2 (GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) in 8 patients with type 1 diabetes mellitus (T1DM) without paracrine intraislet influence of insulin (C-peptide negative following a 5 g...... intravenous arginine stimulation; on study days only treated with basal insulin substitution). On 3 study days, 180-minute two-step glucose clamps were performed. Plasma glucose (PG) was clamped at fasting values, with a mean of 7.4+/-0.5 mM in the first 90 min (period 1) and raised 1.5 times the fasting...

  6. Non-peptidic antagonists of the CGRP receptor, BIBN4096BS and MK-0974, interact with the calcitonin receptor-like receptor via methionine-42 and RAMP1 via tryptophan-74.

    Science.gov (United States)

    Miller, Philip S; Barwell, James; Poyner, David R; Wigglesworth, Mark J; Garland, Stephen L; Donnelly, Dan

    2010-01-01

    The receptor for calcitonin gene-related peptide (CGRP) has been the target for the development of novel small molecule antagonists for the treatment of migraine. Two such antagonists, BIBN4096BS and MK-0974, have shown great promise in clinical trials and hence a deeper understanding of the mechanism of their interaction with the receptor is now required. The structure of the CGRP receptor is unusual since it is comprised of a hetero-oligomeric complex between the calcitonin receptor-like receptor (CRL) and an accessory protein (RAMP1). Both the CLR and RAMP1 components have extracellular domains which interact with each other and together form part of the peptide-binding site. It seems likely that the antagonist binding site will also be located on the extracellular domains and indeed Trp-74 of RAMP1 has been shown to form part of the binding site for BIBN4096BS. However, despite a chimeric study demonstrating the role of the N-terminal domain of CLR in antagonist binding, no specific residues have been identified. Here we carry out a mutagenic screen of the extreme N-terminal domain of CLR (residues 23-63) and identify a mutant, Met-42-Ala, which displays 48-fold lower affinity for BIBN4096BS and almost 900-fold lower affinity for MK-0974. In addition, we confirm that the Trp-74-Lys mutation at human RAMP1 reduces BIBN4096BS affinity by over 300-fold and show for the first time a similar effect for MK-0974 affinity. The data suggest that the non-peptide antagonists occupy a binding site close to the interface of the N-terminal domains of CLR and RAMP1. Copyright 2009 Elsevier Inc. All rights reserved.

  7. High cleavage efficiency of a 2A peptide derived from porcine teschovirus-1 in human cell lines, zebrafish and mice.

    Directory of Open Access Journals (Sweden)

    Jin Hee Kim

    Full Text Available When expression of more than one gene is required in cells, bicistronic or multicistronic expression vectors have been used. Among various strategies employed to construct bicistronic or multicistronic vectors, an internal ribosomal entry site (IRES has been widely used. Due to the large size and difference in expression levels between genes before and after IRES, however, a new strategy was required to replace IRES. A self-cleaving 2A peptide could be a good candidate to replace IRES because of its small size and high cleavage efficiency between genes upstream and downstream of the 2A peptide. Despite the advantages of the 2A peptides, its use is not widespread because (i there are no publicly available cloning vectors harboring a 2A peptide gene and (ii comprehensive comparison of cleavage efficiency among various 2A peptides reported to date has not been performed in different contexts. Here, we generated four expression plasmids each harboring different 2A peptides derived from the foot-and-mouth disease virus, equine rhinitis A virus, Thosea asigna virus and porcine teschovirus-1, respectively, and evaluated their cleavage efficiency in three commonly used human cell lines, zebrafish embryos and adult mice. Western blotting and confocal microscopic analyses revealed that among the four 2As, the one derived from porcine teschovirus-1 (P2A has the highest cleavage efficiency in all the contexts examined. We anticipate that the 2A-harboring cloning vectors we generated and the highest efficiency of the P2A peptide we demonstrated would help biomedical researchers easily adopt the 2A technology when bicistronic or multicistronic expression is required.

  8. Bicyclic peptide inhibitor of urokinase-type plasminogen activator

    DEFF Research Database (Denmark)

    Roodbeen, Renée; Jensen, Berit Paaske; Jiang, Longguang

    2013-01-01

    The development of protease inhibitors for pharmacological intervention has taken a new turn with the use of peptide-based inhibitors. Here, we report the rational design of bicyclic peptide inhibitors of the serine protease urokinase-type plasminogen activator (uPA), based on the established...... investigated the solution structures of the bicyclic peptide by NMR spectroscopy to map possible conformations. An X-ray structure of the bicyclic-peptide-uPA complex confirmed an interaction similar to that for the previous upain-1/upain-2-uPA complexes. These physical studies of the peptide...

  9. Comparison Review of Short-Acting and Long-Acting Glucagon-like Peptide-1 Receptor Agonists

    OpenAIRE

    Uccellatore, Annachiara; Genovese, Stefano; Dicembrini, Ilaria; Mannucci, Edoardo; Ceriello, Antonio

    2015-01-01

    Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs) are useful tools for treating type 2 diabetes mellitus. In their recent position statement, the American Diabetes Association and European Association for the Study of Diabetes recommend GLP1-RAs as add-on to metformin when therapeutic goals are not achieved with monotherapy, particularly for patients who wish to avoid weight gain or hypoglycemia. GLP1-RAs differ substantially in their duration of action, frequency of administratio...

  10. Intravenous glucagon-like peptide 1 normalizes blood glucose after major surgery in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Meier, Juris J; Weyhe, Dirk; Michaely, Mark

    2004-01-01

    of GLP-1 (1.2 pmol x kg x min) and placebo over 8 hrs, each administered in randomized order in the fasting state. C-reactive protein concentrations of 4.9+/-4.2 mg/dL indicated a systemic inflammation. Blood was drawn in 30-min intervals for glucose (glucose oxidase), insulin, C-peptide, glucagon...... practicability and the risk of hypoglycemia. Therefore, the glucose-lowering effect of the incretin hormone glucagon-like peptide 1 (GLP-1) was investigated in patients with type 2 diabetes after major surgery. DESIGN: Randomised clinical study. SETTING: A surgical unit of a university hospital. PATIENTS......, and GLP-1 (specific immunoassays). Statistics were done with repeated-measures analysis of variance and Duncan's post hoc tests. MAIN RESULTS: During the intravenous infusion of GLP-1, plasma glucose concentrations were significantly lowered, reaching the normoglycemic fasting glucose range within 150...

  11. Exendin-4, a glucagon-like peptide-1 receptor agonist, reduces intimal thickening after vascular injury

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Hiromasa [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Nomiyama, Takashi, E-mail: tnomiyama@fukuoka-u.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Mita, Tomoya; Yasunari, Eisuke; Azuma, Kosuke; Komiya, Koji; Arakawa, Masayuki; Jin, Wen Long; Kanazawa, Akio [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Kawamori, Ryuzo [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Sportology Center, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Center for Beta Cell Biology and Regeneration, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Fujitani, Yoshio; Hirose, Takahisa [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Watada, Hirotaka, E-mail: hwatada@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan); Sportology Center, Juntendo University Graduate School of Medicine, Tokyo 113-8421 (Japan)

    2011-02-04

    Research highlights: {yields} Exendin-4 reduces neointimal formation after vascular injury in a mouse model. {yields} Exendin-4 dose not alter metabolic parameters in non-diabetic, non-obese mouse model. {yields} Exendin-4 reduces PDGF-induced cell proliferation in cultured SMCs. {yields} Exendin-4 may reduces neointimal formation after vascular injury at least in part through its direct action on SMCs. -- Abstract: Glucagon-like peptide-1 is a hormone secreted by L cells of the small intestine and stimulates glucose-dependent insulin response. Glucagon-like peptide-1 receptor agonists such as exendin-4 are currently used in type 2 diabetes, and considered to have beneficial effects on the cardiovascular system. To further elucidate the effect of glucagon-like peptide-1 receptor agonists on cardiovascular diseases, we investigated the effects of exendin-4 on intimal thickening after endothelial injury. Under continuous infusion of exendin-4 at 24 nmol/kg/day, C57BL/6 mice were subjected to endothelial denudation injury of the femoral artery. Treatment of mice with exendin-4 reduced neointimal formation at 4 weeks after arterial injury without altering body weight or various metabolic parameters. In addition, in vitro studies of isolated murine, rat and human aortic vascular smooth muscle cells showed the expression of GLP-1 receptor. The addition of 10 nM exendin-4 to cultured smooth muscle cells significantly reduced their proliferation induced by platelet-derived growth factor. Our results suggested that exendin-4 reduced intimal thickening after vascular injury at least in part by the suppression of platelet-derived growth factor-induced smooth muscle cells proliferation.

  12. Exendin-4, a glucagon-like peptide-1 receptor agonist, reduces intimal thickening after vascular injury

    International Nuclear Information System (INIS)

    Goto, Hiromasa; Nomiyama, Takashi; Mita, Tomoya; Yasunari, Eisuke; Azuma, Kosuke; Komiya, Koji; Arakawa, Masayuki; Jin, Wen Long; Kanazawa, Akio; Kawamori, Ryuzo; Fujitani, Yoshio; Hirose, Takahisa; Watada, Hirotaka

    2011-01-01

    Research highlights: → Exendin-4 reduces neointimal formation after vascular injury in a mouse model. → Exendin-4 dose not alter metabolic parameters in non-diabetic, non-obese mouse model. → Exendin-4 reduces PDGF-induced cell proliferation in cultured SMCs. → Exendin-4 may reduces neointimal formation after vascular injury at least in part through its direct action on SMCs. -- Abstract: Glucagon-like peptide-1 is a hormone secreted by L cells of the small intestine and stimulates glucose-dependent insulin response. Glucagon-like peptide-1 receptor agonists such as exendin-4 are currently used in type 2 diabetes, and considered to have beneficial effects on the cardiovascular system. To further elucidate the effect of glucagon-like peptide-1 receptor agonists on cardiovascular diseases, we investigated the effects of exendin-4 on intimal thickening after endothelial injury. Under continuous infusion of exendin-4 at 24 nmol/kg/day, C57BL/6 mice were subjected to endothelial denudation injury of the femoral artery. Treatment of mice with exendin-4 reduced neointimal formation at 4 weeks after arterial injury without altering body weight or various metabolic parameters. In addition, in vitro studies of isolated murine, rat and human aortic vascular smooth muscle cells showed the expression of GLP-1 receptor. The addition of 10 nM exendin-4 to cultured smooth muscle cells significantly reduced their proliferation induced by platelet-derived growth factor. Our results suggested that exendin-4 reduced intimal thickening after vascular injury at least in part by the suppression of platelet-derived growth factor-induced smooth muscle cells proliferation.

  13. A conserved chloramphenicol binding site at the entrance to the ribosomal peptide exit tunnel

    DEFF Research Database (Denmark)

    Long, Katherine S; Porse, Bo T

    2003-01-01

    , of E.coli 23S rRNA and G2084 (2058 in E.coli numbering) in domain V of H.halobium 23S rRNA. The modification sites overlap with a portion of the macrolide binding site and cluster at the entrance to the peptide exit tunnel. The data correlate with the recently reported chloramphenicol binding site...... on an archaeal ribosome and suggest that a similar binding site is present on the E.coli ribosome....

  14. Disturbed release of gastrointestinal peptides in anorexia nervosa and in obesity.

    Science.gov (United States)

    Baranowska, B; Radzikowska, M; Wasilewska-Dziubinska, E; Roguski, K; Borowiec, M

    2000-04-01

    It is commonly accepted that some neuropeptides play an important role in the control of appetite and hormonal secretion. Several gastrointestinal peptides may affect on central control of appetite via vagal and spinal nerves. The aim of this study was to evaluate the release of gastrointestinal peptides in anorexia nervosa and in obesity, because in these diseases the disturbances in the control of appetite and hormonal secretion were found. Material consisted of 30 women with anorexia nervosa aged 16-29 years (mean 22 years) and 23 women with obesity aged 19-33 years (mean 29 years) and 25 lean women of control group. In women with anorexia nervosa as compared with control group we observed a significant increase of plasma vasoactive intestinal peptide (VIP) levels (p anorexia nervosa. These findings suggests that dysfunction of brain-gut axis may be also an important factor in the abnormal control of appetite axcept of hypothalamic dysfunction.

  15. The differences in heparin binding for the C-terminal basic-sequence-rich peptides of HPV-16 and HPV-18 capsid protein L1

    International Nuclear Information System (INIS)

    Sun Jian; Yu Jisheng; Yu Zhiwu; Zha Xiao; Wu Yuqing

    2012-01-01

    Graphial abstract: The differences in heparin binding for the C-terminal basic-sequence-rich peptides of HPV-16 and HPV-18 capsid protein L1. Highlights: ► Several driving forces contribute to the interaction between heparin and peptides. ► C-terminal of HPV L1 is a potential candidate for the attachment to host cells. ► The C-terminal peptides of HPV-16 and -18 L1 have different heparin-binding. ► The different heparin-binding provides an explanation for the distinct prevalences. - Abstract: The high-risk types of human papillomaviruses (HPV) HPV-16 and -18 are the predominant types associated with cervical cancer. HPV-16 and -18 account for about 50% and 20%, respectively, of cervical cancers worldwide. While the reason and molecular mechanism of the distinct prevalence and distributions between them remain poorly understood, the binding affinity of cell surface receptor with capsid proteins, especially L1, may be involved. We examined heparin binding with two synthetic peptides corresponding to the 14 amino acid C-terminal peptides of HPV-16 and -18 L1 with the goal of comparing the equivalent residues in different HPV types. Using isothermal titration calorimetry (ITC) and static right-angle light scattering (SLS), we determined the binding constant K, reaction enthalpy ΔH, and other thermodynamic parameters in the interaction. Especially, we assessed the role of specific residues in binding with heparin by comparing the NMR spectra of free and heparin-bound peptides.

  16. Human neutrophil peptide-1 promotes alcohol-induced hepatic fibrosis and hepatocyte apoptosis.

    Directory of Open Access Journals (Sweden)

    Rie Ibusuki

    Full Text Available Neutrophil infiltration of the liver is a typical feature of alcoholic liver injury. Human neutrophil peptide (HNP-1 is an antimicrobial peptide secreted by neutrophils. The aim of this study was to determine if HNP-1 affects ethanol-induced liver injury and to examine the mechanism of liver injury induced by HNP-1.Transgenic (TG mice expressing HNP-1 under the control of a β-actin-based promoter were established. Ethanol was orally administered to HNP-1 TG or wild-type C57BL/6N (WT mice. SK-Hep1 hepatocellular carcinoma cells were used to investigate the effect of HNP-1 on hepatocytes in vitro.After 24 weeks of ethanol intake, hepatic fibrosis and hepatocyte apoptosis were significantly more severe in TG mice than in WT mice. Levels of CD14, TLR4, and IL-6 in liver tissues were higher in TG mice than in WT mice. Apoptosis was accompanied by higher protein levels of caspase-3, caspase-8, and cleaved PARP in liver tissue. In addition, phosphorylated ASK1, ASK1, phosphorylated JNK, JNK1, JNK2, Bax, Bak and Bim were all more abundant in TG mice than in WT mice. In contrast, the level of anti-apoptotic Bcl2 in the liver was significantly lower in TG mice than in WT mice. Analysis of microRNAs in liver tissue showed that miR-34a-5p expression was significantly higher in TG mice than in WT mice. Furthermore, in the presence of ethanol, HNP-1 increased the apoptosis with the decreased level of Bcl2 in a concentration-dependent manner in vitro.HNP-1 secreted by neutrophils may exacerbate alcohol-induced hepatic fibrosis and hepatocyte apoptosis with a decrease in Bcl2 expression and an increase in miR-34a-5p expression.

  17. Sustained glucagon-like peptide 1 expression from encapsulated transduced cells to treat obese diabetic rats.

    Science.gov (United States)

    Moralejo, Daniel; Yanay, Ofer; Kernan, Kelly; Bailey, Adam; Lernmark, Ake; Osborne, William

    2011-04-01

    Obesity and type 2 diabetes (T2D) are two prevalent chronic diseases that have become a major public health concern in industrialized countries. T2D is characterized by hyperglycemia and islet beta cell dysfunction. Glucagon-like peptide 1 (GLP-1) promotes β cell proliferation and neogenesis and has a potent insulinotropic effect. Leptin receptor deficient male rats are obese and diabetic and provide a model of T2D. We hypothesized that their treatment by sustained expression of GLP-1 using encapsulated cells may prevent or delay diabetes onset. Vascular smooth muscle cells (VSMC) retrovirally transduced to secrete GLP-1 were seeded into TheraCyte(TM) encapsulation devices, implanted subcutaneously and rats were monitored for diabetes. Rats that received cell implants showed mean plasma GLP-1 level of 119.3 ± 10.2pM that was significantly elevated over control values of 32.4 ± 2.9pM (P<0.001). GLP-1 treated rats had mean insulin levels of 45.9 ± 2.3ng/ml that were significantly increased over control levels of 7.3±1.5ng/ml (P<0.001). In rats treated before diabetes onset elevations in blood glucose were delayed and rats treated after onset became normoglycemic and showed improved glucose tolerance tests. Untreated diabetic rats possess abnormal islet structures characterized by enlarged islets with α-cell infiltration and multifocal vacuolization. GLP-1 treatment induced normalization of islet structures including a mantle of α-cells and increased islet mass. These data suggest that encapsulated transduced cells may offer a potential long term treatment of patients. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  18. Tumor-Triggered Geometrical Shape Switch of Chimeric Peptide for Enhanced in Vivo Tumor Internalization and Photodynamic Therapy.

    Science.gov (United States)

    Han, Kai; Zhang, Jin; Zhang, Weiyun; Wang, Shibo; Xu, Luming; Zhang, Chi; Zhang, Xianzheng; Han, Heyou

    2017-03-28

    Geometrical shape of nanoparticles plays an important role in cellular internalization. However, the applicability in tumor selective therapeutics is still scarcely reported. In this article, we designed a tumor extracellular acidity-responsive chimeric peptide with geometrical shape switch for enhanced tumor internalization and photodynamic therapy. This chimeric peptide could self-assemble into spherical nanoparticles at physiological condition. While at tumor extracellular acidic microenvironment, chimeric peptide underwent detachment of acidity-sensitive 2,3-dimethylmaleic anhydride groups. The subsequent recovery of ionic complementarity between chimeric peptides resulted in formation of rod-like nanoparticles. Both in vitro and in vivo studies demonstrated that this acidity-triggered geometrical shape switch endowed chimeric peptide with accelerated internalization in tumor cells, prolonged accumulation in tumor tissue, enhanced photodynamic therapy, and minimal side effects. Our results suggested that fusing tumor microenvironment with geometrical shape switch should be a promising strategy for targeted drug delivery.

  19. Mapping of Epitopes Occurring in Bovine α(s1)-Casein Variants by Peptide Microarray Immunoassay.

    Science.gov (United States)

    Lisson, Maria; Erhardt, Georg

    2016-01-01

    Immunoglobulin E epitope mapping of milk proteins reveals important information about their immunologic properties. Genetic variants of αS1-casein, one of the major allergens in bovine milk, are until now not considered when discussing the allergenic potential. Here we describe the complete procedure to assess the allergenicity of αS1-casein variants B and C, which are frequent in most breeds, starting from milk with identification and purification of casein variants by isoelectric focusing (IEF) and anion-exchange chromatography, followed by in vitro gastrointestinal digestion of the casein variants, identification of the resulting peptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), in silico analysis of the variant-specific peptides as allergenic epitopes, and determination of their IgE-binding properties by microarray immunoassay with cow's milk allergic human sera.

  20. Identification of novel dipeptidyl peptidase-IV and angiotensin-I-converting enzyme inhibitory peptides from meat proteins using in silico analysis.

    Science.gov (United States)

    Lafarga, Tomas; O'Connor, Paula; Hayes, Maria

    2014-09-01

    Angiotensin-I-converting enzyme (ACE-I, EC 3.4.15.1), renin (EC 3.4.23.15), and dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) play key roles in the control of hypertension and the development of type-2 diabetes and other diseases associated with metabolic syndrome. The aim of this work was to utilize known in silico methodologies, peptide databases and software including ProtParam (http://web.expasy.org/protparam/), Basic Local Alignment Tool (BLAST), ExPASy PeptideCutter (http://web.expasy.org/peptide_cutter/) and BIOPEP (http://www.uwm.edu.pl/biochemia/index.php/pl/biopep) to assess the release of potentially bioactive DPP-IV, renin and ACE-I inhibitory peptides from bovine and porcine meat proteins including hemoglobin, collagen and serum albumin. These proteins were chosen as they are found commonly in meat by-products such as bone, blood and low-value meat cuts. In addition, the bioactivities of identified peptides were confirmed using chemical synthesis and in vitro bioassays. The concentration of peptide required to inhibit the activity of ACE-I and DPP-IV by 50% was determined for selected, active peptides. Novel ACE-I and DPP-IV inhibitory peptides were identified in this study using both in silico analysis and a literature search to streamline enzyme selection for peptide production. These novel peptides included the ACE-I inhibitory tri-peptide Ile-Ile-Tyr and the DPP-IV inhibitory tri-peptide Pro-Pro-Leu corresponding to sequences f (182-184) and f (326-328) of both porcine and bovine serum albumin which can be released following hydrolysis with the enzymes papain and pepsin, respectively. This work demonstrates that meat proteins are a suitable resource for the generation of bioactive peptides and further demonstrates the usefulness of in silico methodologies to streamline identification and generation of bioactive peptides. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Taylor Dispersion Analysis as a promising tool for assessment of peptide-peptide interactions.

    Science.gov (United States)

    Høgstedt, Ulrich B; Schwach, Grégoire; van de Weert, Marco; Østergaard, Jesper

    2016-10-10

    Protein-protein and peptide-peptide (self-)interactions are of key importance in understanding the physiochemical behavior of proteins and peptides in solution. However, due to the small size of peptide molecules, characterization of these interactions is more challenging than for proteins. In this work, we show that protein-protein and peptide-peptide interactions can advantageously be investigated by measurement of the diffusion coefficient using Taylor Dispersion Analysis. Through comparison to Dynamic Light Scattering it was shown that Taylor Dispersion Analysis is well suited for the characterization of protein-protein interactions of solutions of α-lactalbumin and human serum albumin. The peptide-peptide interactions of three selected peptides were then investigated in a concentration range spanning from 0.5mg/ml up to 80mg/ml using Taylor Dispersion Analysis. The peptide-peptide interactions determination indicated that multibody interactions significantly affect the PPIs at concentration levels above 25mg/ml for the two charged peptides. Relative viscosity measurements, performed using the capillary based setup applied for Taylor Dispersion Analysis, showed that the viscosity of the peptide solutions increased with concentration. Our results indicate that a viscosity difference between run buffer and sample in Taylor Dispersion Analysis may result in overestimation of the measured diffusion coefficient. Thus, Taylor Dispersion Analysis provides a practical, but as yet primarily qualitative, approach to assessment of the colloidal stability of both peptide and protein formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Harnessing supramolecular peptide nanotechnology in biomedical applications

    Directory of Open Access Journals (Sweden)

    Chan KH

    2017-02-01

    Full Text Available Kiat Hwa Chan,1 Wei Hao Lee,2 Shuangmu Zhuo,3 Ming Ni3 1Division of Science, Yale-NUS College, Singapore; 2Department of Chemistry, Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD, USA; 3Fujian Provincial Key Laboratory for Photonics Technology, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Normal University, Fuzhou, People’s Republic of China Abstract: The harnessing of peptides in biomedical applications is a recent hot topic. This arises mainly from the general biocompatibility of peptides, as well as from the ease of tunability of peptide structure to engineer desired properties. The ease of progression from laboratory testing to clinical trials is evident from the plethora of examples available. In this review, we compare and contrast how three distinct self-assembled peptide nanostructures possess different functions. We have 1 nanofibrils in biomaterials that can interact with cells, 2 nanoparticles that can traverse the bloodstream to deliver its payload and also be bioimaged, and 3 nanotubes that can serve as cross-membrane conduits and as a template for nanowire formation. Through this review, we aim to illustrate how various peptides, in their various self-assembled nanostructures, possess great promise in a wide range of biomedical applications and what more can be expected. Keywords: peptides, self-assembly, nanotechnology

  3. Functionalized D-form self-assembling peptide hydrogels for bone regeneration

    Directory of Open Access Journals (Sweden)

    He B

    2016-04-01

    Full Text Available Bin He,1 Yunsheng Ou,1 Ao Zhou,1 Shuo Chen,1 Weikang Zhao,1 Jinqiu Zhao,2 Hong Li,3 Yong Zhu,1 Zenghui Zhao,1 Dianming Jiang1 1Department of Orthopedics, 2Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 3School of Physical Science and Technology, Sichuan University, Chengdu, People’s Republic of China Abstract: Bone defects are very common in orthopedics, and there is great need to develop suitable bone grafts for transplantation in vivo. However, current bone grafts still encounter some limitations, including limited availability, immune rejection, poor osteoinduction and osteoconduction, poor biocompatibility and degradation properties, etc. Self-assembling peptide nanofiber scaffolds have emerged as an important substrate for cell culture and bone regeneration. We report on the structural features (eg, Congo red staining, circular dichroism spectroscopy, transmission electron microscopy, and rheometry assays and osteogenic ability of D-RADA16-RGD peptide hydrogels (with or without basic fibroblast growth factor due to the better stability of peptide bonds formed by these peptides compared with those formed by L-form peptides, and use them to fill the femoral condyle defect of Sprague Dawley rat model. The bone morphology change, two-dimensional reconstructions using microcomputed tomography, quantification of the microcomputed tomography analyses as well as histological analyses have demonstrated that RGD-modified D-form peptide scaffolds are able to enhance extensive bone regeneration. Keywords: bone defect, functionalized D-form self-assembling peptide, D-RADA16-RGD, peptide hydrogel, bone regeneration

  4. The Hsp90 co-chaperones Sti1, Aha1, and P23 regulate adaptive responses to antifungal azoles

    Directory of Open Access Journals (Sweden)

    Xiaokui Gu

    2016-10-01

    Full Text Available Heat Shock Protein 90 (Hsp90 is essential for tumor progression in humans and drug resistance in fungi. However, the roles of its many co-chaperones in antifungal resistance are unknown. In this study, by susceptibility test of Neurospora crassa mutants lacking each of 18 Hsp90/Calcineurin system member genes (including 8 Hsp90 co-chaperone genes to antifungal drugs and other stresses, we demonstrate that the Hsp90 co-chaperones Sti1 (Hop1 in yeast, Aha1, and P23 (Sba1 in yeast were required for the basal resistance to antifungal azoles and heat stress. Deletion of any of them resulted in hypersensitivity to azoles and heat. Liquid chromatography–mass spectrometry (LC-MS analysis showed that the toxic sterols eburicol and 14α-methyl-3,6-diol were significantly accumulated in the sti1 and p23 deletion mutants after ketoconazole treatment, which has been shown before to led to cell membrane stress. At the transcriptional level, Aha1, Sti1, and P23 positively regulate responses to ketoconazole stress by erg11 and erg6, key genes in the ergosterol biosynthetic pathway. Aha1, Sti1, and P23 are highly conserved in fungi, and sti1 and p23 deletion also increased the susceptibility to azoles in Fusarium verticillioides. These results indicate that Hsp90-cochaperones Aha1, Sti1, and P23 are critical for the basal azole resistance and could be potential targets for developing new antifungal agents.

  5. FGF-23 dysregulates calcium homeostasis and electrophysiological properties in HL-1 atrial cells.

    Science.gov (United States)

    Kao, Yu-Hsun; Chen, Yao-Chang; Lin, Yung-Kuo; Shiu, Rong-Jie; Chao, Tze-Fan; Chen, Shih-Ann; Chen, Yi-Jen

    2014-08-01

    Fibroblast growth factor (FGF)-23 is a key regulator of phosphate homeostasis. Higher FGF-23 levels are correlated with poor outcomes in cardiovascular diseases. FGF-23 can produce cardiac hypertrophy and increase intracellular calcium, which can change cardiac electrical activity. However, it is not clear whether FGF-23 possesses arrhythmogenic potential through calcium dysregulation. Therefore, the purposes of this study were to evaluate the electrophysiological effects of FGF-23 and identify the underlying mechanisms. Patch clamp, confocal microscope with Fluo-4 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, calcium homeostasis and calcium regulatory proteins in HL-1 atrial myocytes with and without FGF-23 (10 and 25 ng/mL) incubation for 24 h. FGF-23 (25 ng/mL) increased L-type calcium currents, calcium transient and sarcoplasmic reticulum Ca(2+) contents in HL-1 cells. FGF-23 (25 ng/mL)-treated cells (n = 14) had greater incidences (57%, 17% and 15%, P calcium/calmodulin-dependent protein kinase IIδ and phospholamban (PLB) at threonine 17 but had similar phosphorylation extents of PLB at serine 16, total PLB and sarcoplasmic reticulum Ca(2+) -ATPase protein. Moreover, the FGF receptor inhibitor (PD173074, 10 nM), calmodulin inhibitor (W7, 5 μM) and phospholipase C inhibitor (U73122, 1 μM) attenuated the effects of FGF-23 on calcium/calmodulin-dependent protein kinase II phosphorylation. FGF-23 increases HL-1 cells arrhythmogenesis with calcium dysregulation through modulating calcium-handling proteins. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

  6. Panurgines, novel antimicrobial peptides from the venom of communal bee Panurgus calcaratus (Hymenoptera: Andrenidae).

    Science.gov (United States)

    Čujová, Sabína; Slaninová, Jiřina; Monincová, Lenka; Fučík, Vladimír; Bednárová, Lucie; Štokrová, Jitka; Hovorka, Oldřich; Voburka, Zdeněk; Straka, Jakub; Čeřovský, Václav

    2013-07-01

    Three novel antimicrobial peptides (AMPs), named panurgines (PNGs), were isolated from the venom of the wild bee Panurgus calcaratus. The dodecapeptide of the sequence LNWGAILKHIIK-NH₂ (PNG-1) belongs to the category of α-helical amphipathic AMPs. The other two cyclic peptides containing 25 amino acid residues and two intramolecular disulfide bridges of the pattern Cys8-Cys23 and Cys11-Cys19 have almost identical sequence established as LDVKKIICVACKIXPNPACKKICPK-OH (X=K, PNG-K and X=R, PNG-R). All three peptides exhibited antimicrobial activity against Gram-positive bacteria and Gram-negative bacteria, antifungal activity, and low hemolytic activity against human erythrocytes. We prepared a series of PNG-1 analogs to study the effects of cationicity, amphipathicity, and hydrophobicity on the biological activity. Several of them exhibited improved antimicrobial potency, particularly those with increased net positive charge. The linear analogs of PNG-K and PNG-R having all Cys residues substituted by α-amino butyric acid were inactive, thus indicating the importance of disulfide bridges for the antimicrobial activity. However, the linear PNG-K with all four cysteine residues unpaired, exhibited antimicrobial activity. PNG-1 and its analogs induced a significant leakage of fluorescent dye entrapped in bacterial membrane-mimicking large unilamellar vesicles as well as in vesicles mimicking eukaryotic cell membrane. On the other hand, PNG-K and PNG-R exhibited dye-leakage activity only from vesicles mimicking bacterial cell membrane.

  7. Neutrophil formyl-peptide receptors. Relationship to peptide-induced responses and emphysema.

    Science.gov (United States)

    Stockley, R A; Grant, R A; Llewellyn-Jones, C G; Hill, S L; Burnett, D

    1994-02-01

    A reproducible assay was established to assess the number of formyl-peptide receptors expressed on the surface of human polymorphonuclear leukocytes (PMN). Using this assay the number of receptors was shown to demonstrate wide within- and between-subject variability. However, the receptor numbers were related to the chemotactic response (r = 0.572) and degranulation response (r = 0.512) to the peptide formyl-methionyl-leucyl-phenylalanine. Subsequent studies showed increased receptor numbers on PMN from patients with emphysema (median, 459 x 10(3)/cell; range, 207 to 1,080) as compared with age-matched control subjects (median, 288; range, 168 to 519; p < 0.02), which may explain the increased chemotactic response of the PMN to formyl peptides. This difference was not observed in patients with bronchiectasis, suggesting that the increased receptor number is a feature of emphysema. Furthermore, the increase was largely a feature of smokers with emphysema (median, 463; range, 362 to 1,080), whereas age-matched smokers without emphysema had lower numbers of receptors (p < 0.001; median, 332; range, 243 to 411). This observation suggests a mechanism that may explain the susceptibility of some smokers to the development of emphysema.

  8. Studies on peptide amidase-catalysed C-terminal peptide amidation in organic media with respect to its substrate specificity

    Czech Academy of Sciences Publication Activity Database

    Čeřovský, Václav; Kula, M. R.

    2001-01-01

    Roč. 33, - (2001), s. 183-187 ISSN 0885-4513 R&D Projects: GA ČR GA203/99/1458 Keywords : enzymic amidation * peptide amides * peptide synthesis Subject RIV: CC - Organic Chemistry Impact factor: 1.408, year: 2001

  9. Glycosylation analysis and protein structure determination of murine fetal antigen 1 (mFA1)--the circulating gene product of the delta-like protein (dlk), preadipocyte factor 1 (Pref-1) and stromal-cell-derived protein 1 (SCP-1) cDNAs

    DEFF Research Database (Denmark)

    Krogh, T N; Bachmann, E; Teisner, B

    1997-01-01

    By means of sequence analysis, murine fetal antigen 1 (mFA1) isolated from Mus musculus amniotic fluid was shown to be the circulating protein of the delta-like protein, stromal-cell-derived protein 1 (SCP-1) and preadipocyte factor 1 (Pref-1) gene products. The protein contains 36 cysteine...... residues arranged in six epidermal-growth-factor-like domains. The purification of several C-terminal peptides of varying lengths showed mFA1 to be C-terminal heterogeneous. O-linked glycosylations of the NeuNAc alpha2-3Gal beta1-3(NeuNAc alpha2-6)GalNAc type were present on all C-terminal peptides...... at residues Thr235, Thr244 and Thr248, although glycosylation on Thr244 was only partial. Three N-linked glycosylations were localized in mFA1 (Asn77, Asn142 and Asn151), two of which (Asn142 and Asn151) were in the unusual Asn-Xaa-Cys motif. Fucosylated biantennary complex-type and small amounts (less than 5...

  10. Structures of peptide families by nuclear magnetic resonance spectroscopy and distance geometry

    Energy Technology Data Exchange (ETDEWEB)

    Pease, J.H.

    1989-12-01

    The three dimensional structures of several small peptides were determined using a combination of {sup 1}H nuclear magnetic resonance (NMR) and distance geometry calculations. These techniques were found to be particularly helpful for analyzing structural differences between related peptides since all of the peptides' {sup 1}H NMR spectra are very similar. The structures of peptides from two separate classes are presented. Peptides in the first class are related to apamin, an 18 amino acid peptide toxin from honey bee venom. The {sup 1}H NMR assignments and secondary structure determination of apamin were done previously. Quantitative NMR measurements and distance geometry calculations were done to calculate apamin's three dimensional structure. Peptides in the second class are 48 amino acid toxins from the sea anemone Radianthus paumotensis. The {sup 1}H NMR assignments of toxin II were done previously. The {sup 1}H NMR assignments of toxin III and the distance geometry calculations for both peptides are presented.

  11. BDNF pro-peptide regulates dendritic spines via caspase-3

    OpenAIRE

    Guo, J; Ji, Y; Ding, Y; Jiang, W; Sun, Y; Lu, B; Nagappan, G

    2016-01-01

    The precursor of brain-derived neurotrophic factor (BDNF) (proBDNF) is enzymatically cleaved, by either intracellular (furin/PC1) or extracellular proteases (tPA/plasmin/MMP), to generate mature BDNF (mBDNF) and its pro-peptide (BDNF pro-peptide). Little is known about the function of BDNF pro-peptide. We have developed an antibody that specifically detects cleaved BDNF pro-peptide, but not proBDNF or mBDNF. Neuronal depolarization elicited a marked increase in extracellular BDNF pro-peptide,...

  12. Crystal Structure of Glucagon-like Peptide-1 in Complex with the Extracellular Domain of the Glucagon-like Peptide-1 Receptor*

    Science.gov (United States)

    Underwood, Christina Rye; Garibay, Patrick; Knudsen, Lotte Bjerre; Hastrup, Sven; Peters, Günther H.; Rudolph, Rainer; Reedtz-Runge, Steffen

    2010-01-01

    GLP-1 (glucagon-like peptide-1) is an incretin released from intestinal L-cells in response to food intake. Activation of the GLP-1 receptor potentiates the synthesis and release of insulin from pancreatic β-cells in a glucose-dependent manner. The GLP-1 receptor belongs to class B of the G-protein-coupled receptors, a subfamily characterized by a large N-terminal extracellular ligand binding domain. Exendin-4 and GLP-1 are 50% identical, and exendin-4 is a full agonist with similar affinity and potency for the GLP-1 receptor. We recently solved the crystal structure of the GLP-1 receptor extracellular domain in complex with the competitive antagonist exendin-4(9–39). Interestingly, the isolated extracellular domain binds exendin-4 with much higher affinity than the endogenous agonist GLP-1. Here, we have solved the crystal structure of the extracellular domain in complex with GLP-1 to 2.1 Åresolution. The structure shows that important hydrophobic ligand-receptor interactions are conserved in agonist- and antagonist-bound forms of the extracellular domain, but certain residues in the ligand-binding site adopt a GLP-1-specific conformation. GLP-1 is a kinked but continuous α-helix from Thr13 to Val33 when bound to the extracellular domain. We supplemented the crystal structure with site-directed mutagenesis to link the structural information of the isolated extracellular domain with the binding properties of the full-length receptor. The data support the existence of differences in the binding modes of GLP-1 and exendin-4 on the full-length GLP-1 receptor. PMID:19861722

  13. Radiolabeled peptides: experimental and clinical applications

    International Nuclear Information System (INIS)

    Thakur, M.L.; Pallela, V.R.

    1998-01-01

    Radiolabeled receptor specific biomolecules hold unlimited potential in nuclear medicine. During the past few years much attention has been drawn to the development radiolabeled peptides for a variety of diagnostic applications, as well as for therapy of malignant tumors. Although only one peptide, In-111-DTPA-(D)-Phe 1 -octreotide, is available commercially for oncologic imaging, many more have been examined in humans with hematological disorders, and the early results appear to be promising. Impetus generated by these results have prompted investigators to label peptides with such radionuclides as Tc-99m, I-123, F-18, Cu-64, and Y-90. This review is intended to highlight the qualities of peptides, summarize the clinical results, and address some important issues associated with radiolabeling of highly potent peptides. While doing so, various methods of radiolabeling have been described, and their strengths and weaknesses have also been discussed. (author)

  14. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  15. 2-d and 1-d Nanomaterials Construction through Peptide Computational Design and Solution Assembly

    Science.gov (United States)

    Pochan, Darrin

    Self-assembly of molecules is an attractive materials construction strategy due to its simplicity in application. By considering peptidic molecules in the bottom-up materials self-assembly design process, one can take advantage of inherently biomolecular attributes; intramolecular folding events, secondary structure, and electrostatic/H-bonding/hydrophobic interactions to define hierarchical material structure and consequent properties. Importantly, while biomimicry has been a successful strategy for the design of new peptide molecules for intermolecular assembly, computational tools have been developed to de novo design peptide molecules required for construction of pre-determined, desired nanostructures and materials. A new system comprised of coiled coil bundle motifs theoretically designed to assemble into designed, one and two-dimensional nanostructures will be introduced. The strategy provides the opportunity for arbitrary nanostructure formation, i.e. structures not observed in nature, with peptide molecules. Importantly, the desired nanostructure was chosen first while the peptides needed for coiled coil formation and subsequent nanomaterial formation were determined computationally. Different interbundle, two-dimensional nanostructures are stabilized by differences in amino acid composition exposed on the exterior of the coiled coil bundles. Computation was able to determine molecules required for different interbundle symmetries within two-dimensional sheets stabilized by subtle differences in amino acid composition of the inherent peptides. Finally, polymers were also created through covalent interactions between bundles that allowed formation of architectures spanning flexible network forming chains to ultra-stiff polymers, all with the same building block peptides. The success of the computational design strategy is manifested in the nanomaterial results as characterized by electron microscopy, scattering methods, and biophysical techniques. Support

  16. Rac1 Regulates the Proliferation, Adhesion, Migration, and Differentiation of MDPC-23 Cells.

    Science.gov (United States)

    Ren, Jing; Liang, Guobin; Gong, Li; Guo, Bing; Jiang, Hongwei

    2017-04-01

    Stem cells are responsible for replacing damaged pulp tissue; therefore, promoting their survival and inducing their adhesion to dentin are vital. As a member of the Rho family of guanosine triphosphatases, Rac1 is an important regulator of osteoblast functions. However, little is known about its role in regenerative endodontic procedures. The current study examined the role of Rac1 in the proliferation, migration, and odontoblastic differentiation of MDPC-23 cells. MDPC-23 cells were transfected with small interfering RNA to knock down Rac1 expression, and then their proliferation, migration, adhesion, and odontoblastic differentiation were examined in vitro. MDPC-23 cells transfected with si-Rac1 exhibited the increased expression of several key odontogenic protein markers, including Dmp1, Dspp, Runx2, and alkaline phosphatase, as well as decreased proliferation and migration in vitro. The results suggest that Rac1 might regulate nuclear factor kappa B signaling in MDPC-23 cells. Rac1 may have vital roles in the proliferation, migration, adhesion, and odontoblastic differentiation of MDPC-23 cells. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Peptides in fermented Finnish milk products

    Directory of Open Access Journals (Sweden)

    Minna Kahala

    1993-09-01

    Full Text Available This study was conducted to investigate the rate of proteolysis and peptide profiles of different Finnish fermented milk products. The highest rate of proteolysis was observed in Biokefir, while the greatest change in the rate of proteolysis was observed in Gefilus®. Differences in starters and manufacturing processes reflected on the peptide profiles of the products. Most of the identified peptides originated from either the N- or C-terminal region of β-casein or from the N-terminal region of αs1-casein.

  18. Comparison of the amyloid pore forming properties of rat and human Alzheimer’s beta-amyloid peptide 1-42: Calcium imaging data

    Directory of Open Access Journals (Sweden)

    Coralie Di Scala

    2016-03-01

    Full Text Available The data here consists of calcium imaging of human neuroblastoma SH-SY5Y cells treated with the calcium-sensitive dye Fluo-4AM and then incubated with nanomolar concentrations of either human or rat Alzheimer’s β-amyloid peptide1-42. These data are both of a qualitative (fluorescence micrographs and semi-quantitative nature (estimation of intracellular calcium concentrations of cells probed by Aβ1-42 peptides vs. control untreated cells. Since rat Aβ1-42 differs from its human counterpart at only three amino acid positions, this comparative study is a good assessment of the specificity of the amyloid pore forming assay. The interpretation of this dataset is presented in the accompanying study “Broad neutralization of calcium-permeable amyloid pore channels with a chimeric Alzheimer/Parkinson peptide targeting brain gangliosides” [1].

  19. Cloning of human basic A1, a distinct 59-kDa dystrophin-associated protein encoded on chromosome 8q23-24

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, A.H. [Harvard Medical School, Boston, MA (United States); Yoshida, Mikiharu; Hagiwara, Yasuko; Ozawa, Eijiro [National Institute of Neuroscience, Ogawa Higashi, Kodaira (Japan); Anderson, M.S.; Feener, C.A.; Selig, S. [Howard Hughes Medical Institute at Children`s Hospital, Boston, MA (United States); Kunkel, L.M. [Harvard Medical School, Boston, MA (United States)]|[Howard Hughes Medical Institute at Children`s Hosptial, Boston, MA (United States)

    1994-05-10

    Duchenne and Becker muscular dystrophies are caused by defects of dystrophin, which forms a part of the membrane cytoskeleton of specialized cells such as muscle. It has been previously shown that the dystrophin-associated protein A1 (59-kDa DAP) is actually a heterogeneous group of phosphorylated proteins consisting of an acidic ({alpha}-A1) and a distinct basic ({beta}-A1) component. Partial peptide sequence of the A1 complex purified from rabbit muscle permitted the design of oligonucleotide probes that were used to isolate a cDNA for one human isoform of A1. This cDNA encodes a basic A1 isoform that is distinct from the recently described syntrophins in Torpedo and mouse and is expressed in many tissues with at least five distinct mRNA species of 5.9, 4.8, 4.3, 3.1, and 1.5 kb. A comparison of the human cDNA sequence with the GenBank expressed sequence tag (EST) data base has identified a relative from human skeletal muscle, EST25263, which is probably a human homologue of the published mouse syntrophin 2. The authors have mapped the human basic component of A1 and EST25263 genes to chromosomes 8q23-24 and 16, respectively.

  20. Feasibility of Cancer Immunotherapy with WT1 Peptide Vaccination for Solid and Hematological Malignancies in Children.

    Science.gov (United States)

    Sawada, Akihisa; Inoue, Masami; Kondo, Osamu; Yamada-Nakata, Kayo; Ishihara, Takashi; Kuwae, Yuko; Nishikawa, Masanori; Ammori, Yasuhiro; Tsuboi, Akihiro; Oji, Yusuke; Koyama-Sato, Maho; Oka, Yoshihiro; Yasui, Masahiro; Sugiyama, Haruo; Kawa, Keisei

    2016-02-01

    Advances in cancer immunotherapy in the pediatric field are needed in order to improve the prognosis of children with malignancies. We conducted a prospective phase I/II study of WT1 peptide vaccination for children with relapsed or refractory malignancies. The main eligibility criteria were affected tissues or leukemic cells expressing the WT1 gene, and patients (and donors for allogeneic hematopoietic stem cell transplantation) having HLA-A*24:02. Vaccination using the WT1 peptide (CYTWNQMNL), which was modified for higher affinity to this HLA-type molecule with the adjuvant Montanide ISA51, was performed weekly 12 times. Twenty-six patients were enrolled and 13 (50.0%) completed the vaccination 12 times. Evidence for the induction of WT1-specific cytotoxic T-lymphocyte (CTL) responses without severe systemic side effects was obtained. Two out of 12 patients with bulky disease exhibited a transient clinical effect (one mixed response and one stable disease), three out of six patients with minimal residual disease achieved transient molecular remission, and five out of eight patients without a detectable level of the molecular marker, but with a high risk of relapse, had the best outcome of long-term continuous complete remission. WT1 vaccination is a safe immunotherapy and induced WT1-specific CTL responses in children; however, as a single agent, vaccination only provided patients in remission, but with a high risk of relapse, with "long-term benefits" in the context of its use for relapse prevention. WT1 peptide-based treatments in combination with other modalities, such as anti-tumor drugs or immunomodulating agents, need to be planned. © 2015 Wiley Periodicals, Inc.

  1. In vitro fibrillization of Alzheimer’s amyloid-β peptide (1-42)

    Energy Technology Data Exchange (ETDEWEB)

    Tiiman, Ann [Department of Gene Technology, Tallinn University of Technology, Tallinn 12618 (Estonia); Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Stockholm, 106 91 (Sweden); Krishtal, Jekaterina; Palumaa, Peep; Tõugu, Vello, E-mail: vello.tougu@ttu.ee [Department of Gene Technology, Tallinn University of Technology, Tallinn 12618 (Estonia)

    2015-09-15

    The amyloid deposition in the form of extracellular fibrillar aggregates of amyloid-β (Aβ) peptide is a critical pathological event in Alzheimer’s disease. Here, we report a systematic investigation of the effects of environmental factors on the kinetics of Aβ fibrillization in vitro. The effects of Aβ42 peptide concentration, temperature, pH, added solvents and the ratio of Aβ40 and Aβ42 on the peptide fibrillization under agitated conditions was studied. The analysis show that the rate of fibril growth by monomer addition is not limited by diffusion but by rearrangement in the monomer structure, which is enhanced by low concentrations of fluorinated alcohols and characterized by the activation energy of 12 kcal/mol. Fibrillization rate decreases at pH values below 7.0 where simultaneous protonation of His 13 and 14 inhibits fibril formation. The lag period for Aβ42 was only twofold shorter and the fibril growth rate twofold faster than those of Aβ40. Lag period was shortened and the fibrillization rate was increased only at 90% content of Aβ42.

  2. Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

    African Journals Online (AJOL)

    Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

  3. Solution structure of the 45-residue MgATP-binding peptide of adenylate kinase as examined by 2-D NMR, FTIR, and CD spectroscopy

    International Nuclear Information System (INIS)

    Fry, D.C.; Byler, D.M.; Susi, H.; Brown, M.; Kuby, S.A.; Mildvan, A.S.

    1988-01-01

    The structure of a synthetic peptide corresponding to residues 1-45 of rabbit muscle adenylate kinase has been studied in aqueous solution by two-dimensional NMR, FTIR, and CD spectroscopy. This peptide, which binds MgATP and is believed to represent most of the MgATP-binding site of the enzyme, appears to maintain a conformation similar to that of residues 1-45 in the X-ray structure of intact porcine adenylate kinase, with 42% of the residues of the peptide showing NOEs indicative of phi and psi angles corresponding to those found in the protein. The NMR studies suggest that the peptide is composed of two helical regions of residues 4-7 and 23-29, and three stretches of β-strand at residues 8-15, 30-32, and 35-40, yielding an overall secondary structure consisting of 24% α-helix, 38% β-structure, and 38% aperiodic. Although the resolution-enhanced amide I band of the peptide FTIR spectrum is broad and rather featureless, possible due to disorder, it can be fit by using methods developed on well-characterized globular proteins. The CD spectrum is best fit by assuming the presence of at most 13% α-helix in the peptide, 24 +/- 2% β-structure, and 66 +/- 4% aperiodic. The inability of the high-frequency FTIR and CD methods to detect helices in the amount found by NMR may result from the short helical lengths as well as from static and dynamic disorder in the peptide. Upon binding of MgATP, numerous conformation changes in the backbone of the peptide are detected by NMR, with smaller alterations in the overall secondary structure as assess by CD

  4. Peptide folding in the presence of interacting protein crowders

    Energy Technology Data Exchange (ETDEWEB)

    Bille, Anna, E-mail: anna.bille@thep.lu.se; Irbäck, Anders, E-mail: anders@thep.lu.se [Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, SE-223 62 Lund (Sweden); Mohanty, Sandipan, E-mail: s.mohanty@fz-juelich.de [Jülich Supercomputing Centre, Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-05-07

    Using Monte Carlo methods, we explore and compare the effects of two protein crowders, BPTI and GB1, on the folding thermodynamics of two peptides, the compact helical trp-cage and the β-hairpin-forming GB1m3. The thermally highly stable crowder proteins are modeled using a fixed backbone and rotatable side-chains, whereas the peptides are free to fold and unfold. In the simulations, the crowder proteins tend to distort the trp-cage fold, while having a stabilizing effect on GB1m3. The extent of the effects on a given peptide depends on the crowder type. Due to a sticky patch on its surface, BPTI causes larger changes than GB1 in the melting properties of the peptides. The observed effects on the peptides stem largely from attractive and specific interactions with the crowder surfaces, and differ from those seen in reference simulations with purely steric crowder particles.

  5. Proteinase-Activated Receptor-1 and Immunomodulatory Effects of a PAR1-Activating Peptide in a Mouse Model of Prostatitis

    Science.gov (United States)

    Stanton, M. Mark; Nelson, Lisa K.; Benediktsson, Hallgrimur; Hollenberg, Morley D.; Buret, Andre G.; Ceri, Howard

    2013-01-01

    Background. Nonbacterial prostatitis has no established etiology. We hypothesized that proteinase-activated receptor-1 (PAR1) can play a role in prostatitis. We therefore investigated the effects of PAR1 stimulation in the context of a new model of murine nonbacterial prostatitis. Methods. Using a hapten (ethanol-dinitrobenzene sulfonic acid- (DNBS-)) induced prostatitis model with both wild-type and PAR1-null mice, we examined (1) the location of PAR1 in the mouse prostate and (2) the impact of a PAR1-activating peptide (TFLLR-NH2: PAR1-TF) on ethanol-DNBS-induced inflammation. Results. Ethanol-DNBS-induced inflammation was maximal at 2 days. In the tissue, PAR1 was expressed predominantly along the apical acini of prostatic epithelium. Although PAR1-TF on its own did not cause inflammation, its coadministration with ethanol-DNBS reduced all indices of acute prostatitis. Further, PAR1-TF administration doubled the prostatic production of interleukin-10 (IL-10) compared with ethanol-DNBS treatment alone. This enhanced IL-10 was not observed in PAR1-null mice and was not caused by the reverse-sequence receptor-inactive peptide, RLLFT-NH2. Surprisingly, PAR1-TF, also diminished ethanol-DNBS-induced inflammation in PAR1-null mice. Conclusions. PAR1 is expressed in the mouse prostate and its activation by PAR1-TF elicits immunomodulatory effects during ethanol-DNBS-induced prostatitis. However, PAR1-TF also diminishes ethanol-DNBS-induced inflammation via a non-PAR1 mechanism by activating an as-yet unknown receptor. PMID:24459330

  6. Propensity of a single-walled carbon nanotube-peptide to mimic a KK10 peptide in an HLA-TCR complex

    Science.gov (United States)

    Feng, Mei; Bell, David R.; Zhou, Ruhong

    2017-12-01

    The application of nanotechnology to improve disease diagnosis, treatment, monitoring, and prevention is the goal of nanomedicine. We report here a theoretical study of a functionalized single-walled carbon nanotube (CNT) mimic binding to a human leukocyte antigen-T cell receptor (HLA-TCR) immune complex as a first attempt of a potential nanomedicine for human immunodeficiency virus (HIV) vaccine development. The carbon nanotube was coated with three arginine residues to imitate the HIV type 1 immunodominant viral peptide KK10 (gag 263-272: KRWIILGLNK), named CNT-peptide hereafter. Through molecular dynamics simulations, we explore the CNT-peptide and KK10 binding to an important HLA-TCR complex. Our results suggest that the CNT-peptide and KK10 bind comparably to the HLA-TCR complex, but the CNT-peptide forms stronger interactions with the TCR. Desorption simulations highlight the innate flexibility of KK10 over the CNT-peptide, resulting in a slightly higher desorption energy required for KK10 over the CNT-peptide. Our findings indicate that the designed CNT-peptide mimic has favorable propensity to activate TCR pathways and should be further explored to understand therapeutic potential.

  7. Electrostatic interaction energy and factor 1.23

    Science.gov (United States)

    Rubčić, A.; Arp, H.; Rubčić, J.

    The factor F≫1.23 has originally been found in the redshift of quasars. Recently, it has been found in very different physical phenomena: the life-time of muonium, the masses of elementary particles (leptons, quarks,...), the correlation of atomic weight (A) and atomic number (Z) and the correlation of the sum of masses of all orbiting bodies with the mass of the central body in gravitational systems.

  8. Peptide-Functionalized Luminescent Iridium Complexes for Lifetime Imaging of CXCR4 Expression

    NARCIS (Netherlands)

    Kuil, J.; Steunenberg, P.; Chin, P.T.K.; Oldenburg, J.; Jalink, K.; Velders, A.H.; Leeuwen, F.W.B. van

    2011-01-01

    The chemokine receptor 4 (CXCR4) is over-expressed in 23 types of cancer in which it plays a role in, among others, the metastatic spread. For this reason it is a potential biomarker for the field of diagnostic oncology. The antagonistic Ac-TZ14011 peptide, which binds to CXCR4, has been conjugated

  9. Glucagon-like peptide-1 inhibits blood-brain glucose transfer in humans

    DEFF Research Database (Denmark)

    Lerche, Susanne; Brock, Birgitte; Rungby, Jørgen

    2008-01-01

    OBJECTIVE: Glucagon-like peptide-1 (GLP-1) has many effects on glucose homeostasis, and GLP-1 receptors are broadly represented in many tissues including the brain. Recent research in rodents suggests a protective effect of GLP-1 on brain tissue. The mechanism is unknown. We therefore tested......-independent effect of GLP-1 on unidirectional glucose transport into the brain during a pituitary-pancreatic normoglycemic (plasma glucose approximately 4.5 mmol/l) clamp with 18-fluoro-deoxy-glucose as tracer. RESULTS: On average, GLP-1 reduced cerebral glucose transport by 27% in total cerebral gray matter (P = 0...... that a hormone involved in postprandial glucose regulation also limits glucose delivery to brain tissue and hence provides a possible regulatory mechanism for the link between plasma glucose and brain glucose. Because GLP-1 reduces glucose uptake across the intact blood-brain barrier at normal glycemia, GLP-1...

  10. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  11. Amyloid–β peptides time-dependent structural modifications: AFM and voltammetric characterization

    Energy Technology Data Exchange (ETDEWEB)

    Enache, Teodor Adrian; Chiorcea-Paquim, Ana-Maria; Oliveira-Brett, Ana Maria, E-mail: brett@ci.uc.pt

    2016-07-05

    The human amyloid beta (Aβ) peptides, Aβ{sub 1-40} and Aβ{sub 1-42}, structural modifications, from soluble monomers to fully formed fibrils through intermediate structures, were investigated, and the results were compared with those obtained for the inverse Aβ{sub 40-1} and Aβ{sub 42-1}, mutant Aβ{sub 1-40}Phe{sup 10} and Aβ{sub 1-40}Nle{sup 35}, and rat Aβ{sub 1-40}Rat peptide sequences. The aggregation was followed at a slow rate, in chloride free media and room temperature, and revealed to be a sequence-structure process, dependent on the physicochemical properties of each Aβ peptide isoforms, and occurring at different rates and by different pathways. The fibrilization process was investigated by atomic force microscopy (AFM), via changes in the adsorption morphology from: (i) initially random coiled structures of ∼0.6 nm height, corresponding to the Aβ peptide monomers in random coil or in α-helix conformations, to (ii) aggregates and protofibrils of 1.5–6.0 nm height and (iii) two types of fibrils, corresponding to the Aβ peptide in a β-sheet configuration. The reactivity of the carbon electrode surface was considered. The hydrophobic surface induced rapid changes of the Aβ peptide conformations, and differences between the adsorbed fibrils, formed at the carbon surface (beaded, thin, <2.0 nm height) or in solution (long, smooth, thick, >2.0 nm height), were detected. Differential pulse voltammetry showed that, according to their primary structure, the Aβ peptides undergo oxidation in one or two steps, the first step corresponding to the tyrosine amino acids oxidation, and the second one to the histidine and methionine amino acids oxidation. The fibrilization process was electrochemically detected via the decrease of the Aβ peptide oxidation peak currents that occurred in a time dependent manner. - Highlights: • The Aβ peptide fibrilization process was followed by AFM and DP voltammetry. • The human Aβ{sub 1-40} and Aβ{sub 1

  12. Structure and dynamics of the peptide strand KRFK from the thrombospondin TSP-1 in water.

    Science.gov (United States)

    Taleb Bendiab, W; Benomrane, B; Bounaceur, B; Dauchez, M; Krallafa, A M

    2018-02-14

    Theoretical investigations of a solute in liquid water at normal temperature and pressure can be performed at different levels of theory. Static quantum calculations as well as classical and ab initio molecular dynamics are used to completely explore the conformational space for large solvated molecular systems. In the classical approach, it is essential to describe all of the interactions of the solute and the solvent in detail. Water molecules are very often described as rigid bodies when the most commonly used interaction potentials, such as the SPCE and the TIP4P models, are employed. Recently, a physical model based upon a cluster of rigid water molecules with a tetrahedral architecture (AB 4 ) was proposed that describes liquid water as a mixture of both TIP4P and SPCE molecular species that occur in the proportions implied by the tetrahedral architecture (one central molecule versus four outer molecules; i.e., 20% TIP4P versus 80% SPCE molecules). In this work, theoretical spectroscopic data for a peptide strand were correlated with the structural properties of the peptide strand solvated in water, based on data calculated using different theoretical approaches and physical models. We focused on a particular peptide strand, KRFK (lysine-arginine-phenylalanine-lysine), found in the thrombospondin TSP-1, due to its interesting properties. As the activity and electronic structure of this system is strongly linked to its structure, we correlated its structure with charge-density maps obtained using different semi-empirical charge Q eq equations. The structural and thermodynamic properties obtained from classical simulations were correlated with ab initio molecular dynamics (AIMD) data. Structural changes in the peptide strand were rationalized in terms of the motions of atoms and groups of atoms. To achieve this, conformational changes were investigated using calculated infrared spectra for the peptide in the gas phase and in water solvent. The calculated AIMD

  13. Changes of serum leptin and c-peptide level in children with type 1 diabetic mellitus

    International Nuclear Information System (INIS)

    Du Tongxin; Wang Zizheng; Sun Junjiang; Wang Shukui; Qi Shaokang

    2001-01-01

    To deplore the relationship between leptin and c-peptide in children with type 1 diabetic mellitus (DM). The levels of serum leptin and c-peptide (C-P) in 65 type 1 DM children (including 31 before and after insulin treatment) and 30 normal controls were measured by radioimmunoassay (RIA). The results found that there was significant differences (P < 0.01) in leptin and C-P between DM children and normal controls, also in 31 DM children before and after treatment. It showed a positive correlation between leptin and C-P. The changes of the leptin/C-P ratio in DM children compared with normal controls and that before and after treatment were also significantly different. It suggested that leptin may have close relationship in the development, progress and the occurrence of complications in children with DM and also provide a new clue for their diagnosis treatment and complication occurrence

  14. Highly selective enrichment of phosphorylated peptides from peptide mixtures using titanium dioxide microcolumns

    DEFF Research Database (Denmark)

    Larsen, Martin Røssel; Thingholm, Tine E; Jensen, Ole N

    2005-01-01

    based on TiO2microcolumns and peptide loading in 2,5-dihydroxybenzoic acid (DHB). The effect of DHB was a very efficient reduction in the binding of nonphosphorylated peptides to TiO2 while retaining its high binding affinity for phosphorylated peptides. Thus, inclusion of DHB dramatically increased...... the selectivity of the enrichment of phosphorylated peptides by TiO2. We demonstrated that this new procedure was more selective for binding phosphorylated peptides than IMAC using MALDI mass spectrometry. In addition, we showed that LC-ESI-MSMS was biased toward monophosphorylated peptides, whereas MALDI MS...... was not. Other substituted aromatic carboxylic acids were also capable of specifically reducing binding of nonphosphorylated peptides, whereas phosphoric acid reduced binding of both phosphorylated and nonphosphorylated peptides. A putative mechanism for this intriguing effect is presented....

  15. Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism.

    Science.gov (United States)

    Hansen, Morten S S; Tencerova, Michaela; Frølich, Jacob; Kassem, Moustapha; Frost, Morten

    2018-01-01

    The relationship between gut and skeleton is increasingly recognized as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibit several physiological functions including regulation of islet hormone secretion and glucose levels. A number of GLP-1 receptor agonists (GLP-1RAs) are currently used in treatment of type 2 diabetes and obesity. However, GIP and GLP-1 cognate receptors are widely expressed suggesting that incretin hormones mediate effects beyond control of glucose homeostasis, and reports on associations between incretin hormones and bone metabolism have emerged. The aim of this MiniReview was to provide an overview of current knowledge regarding the in vivo and in vitro effects of GIP and GLP-1 on bone metabolism. We identified a total of 30 pre-clinical and clinical investigations of the effects of GIP, GLP-1 and GLP-1RAs on bone turnover markers, bone mineral density (BMD), bone microarchitecture and fracture risk. Studies conducted in cell cultures and rodents demonstrated that GIP and GLP-1 play a role in regulating skeletal homeostasis, with pre-clinical data suggesting that GIP inhibits bone resorption whereas GLP-1 may promote bone formation and enhance bone material properties. These effects are not corroborated by clinical studies. While there is evidence of effects of GIP and GLP-1 on bone metabolism in pre-clinical investigations, clinical trials are needed to clarify whether similar effects are present and clinically relevant in humans. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  16.  Pleiotropic action of proinsulin C-peptid

    Directory of Open Access Journals (Sweden)

    Michał Usarek

    2012-03-01

    Full Text Available  Proinsulin C-peptide, released in equimolar amounts with insulin by pancreatic β cells, since its discovery in 1967 has been thought to be devoid of biological functions apart from correct insulin processing and formation of disulfide bonds between A and B chains. However, in the last two decades research has brought a substantial amount of data indicating a crucial role of C-peptide in regulating various processes in different types of cells and organs. C-peptide acts presumably via either G-protein-coupled receptor or directly inside the cell, after being internalized. However, a receptor binding this peptide has not been identified yet. This peptide ameliorates pathological changes induced by type 1 diabetes mellitus, including glomerular hyperfiltration, vessel endothelium inflammation and neuron demyelinization. In diabetic patients and diabetic animal models, C-peptide substitution in physiological doses improves the functional and structural properties of peripheral neurons and protects against hyperglycemia-induced apoptosis, promoting neuronal development, regeneration and cell survival. Moreover, it affects glycogen synthesis in skeletal muscles. In vitro C-peptide promotes disaggregation of insulin oligomers, thus enhancing its bioavailability and effects on metabolism. There are controversies concerning the biological action of C-peptide, particularly with respect to its effect on Na /K -ATPase activity. Surprisingly, the excess of circulating peptide associated with diabetes type 2 contributes to atherosclerosis development. In view of these observations, long-term, large-scale clinical investigations using C-peptide physiological doses need to be conducted in order to determine safety and health outcomes of long-term administration of C-peptide to diabetic patients.

  17. The peptide-receptive transition state of MHC-1 molecules: Insight from structure and molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Robinson H.; Mage, M.; Dolan, M.; Wang, R.; Boyd, L.; Revilleza, M.; Natarajan, K.; Myers, N.; Hansen, T.; Margulies, D.

    2012-05-01

    MHC class I (MHC-I) proteins of the adaptive immune system require antigenic peptides for maintenance of mature conformation and immune function via specific recognition by MHC-I-restricted CD8(+) T lymphocytes. New MHC-I molecules in the endoplasmic reticulum are held by chaperones in a peptide-receptive (PR) transition state pending release by tightly binding peptides. In this study, we show, by crystallographic, docking, and molecular dynamics methods, dramatic movement of a hinged unit containing a conserved 3(10) helix that flips from an exposed 'open' position in the PR transition state to a 'closed' position with buried hydrophobic side chains in the peptide-loaded mature molecule. Crystallography of hinged unit residues 46-53 of murine H-2L(d) MHC-I H chain, complexed with mAb 64-3-7, demonstrates solvent exposure of these residues in the PR conformation. Docking and molecular dynamics predict how this segment moves to help form the A and B pockets crucial for the tight peptide binding needed for stability of the mature peptide-loaded conformation, chaperone dissociation, and Ag presentation.

  18. Long-term rescue of dystrophin expression and improvement in muscle pathology and function in dystrophic mdx mice by peptide-conjugated morpholino.

    Science.gov (United States)

    Wu, Bo; Lu, Peijuan; Cloer, Caryn; Shaban, Mona; Grewal, Snimar; Milazi, Stephanie; Shah, Sapana N; Moulton, Hong M; Lu, Qi Long

    2012-08-01

    Exon skipping is capable of correcting frameshift and nonsense mutations in Duchenne muscular dystrophy. Phase 2 clinical trials in the United Kingdom and the Netherlands have reported induction of dystrophin expression in muscle of Duchenne muscular dystrophy patients by systemic administration of both phosphorodiamidate morpholino oligomers (PMO) and 2'-O-methyl phosphorothioate. Peptide-conjugated phosphorodiamidate morpholino offers significantly higher efficiency than phosphorodiamidate morpholino, with the ability to induce near-normal levels of dystrophin, and restores function in both skeletal and cardiac muscle. We examined 1-year systemic efficacy of peptide-conjugated phosphorodiamidate morpholino targeting exon 23 in dystrophic mdx mice. The LD(50) of peptide-conjugated phosphorodiamidate morpholino was determined to be approximately 85 mg/kg. The half-life of dystrophin expression was approximately 2 months in skeletal muscle, but shorter in cardiac muscle. Biweekly injection of 6 mg/kg peptide-conjugated phosphorodiamidate morpholino produced >20% dystrophin expression in all skeletal muscles and ≤5% in cardiac muscle, with improvement in muscle function and pathology and reduction in levels of serum creatine kinase. Monthly injections of 30 mg/kg peptide-conjugated phosphorodiamidate morpholino restored dystrophin to >50% normal levels in skeletal muscle, and 15% in cardiac muscle. This was associated with greatly reduced serum creatine kinase levels, near-normal histology, and functional improvement of skeletal muscle. Our results demonstrate for the first time that regular 1-year administration of peptide-conjugated phosphorodiamidate morpholino can be safely applied to achieve significant therapeutic effects in an animal model. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  19. Novel 2,3-Dihydro-1H-pyrrolo[3,2,1-ij]quinazolin-1-ones: Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Malose J. Mphahlele

    2016-12-01

    Full Text Available Herein we describe the synthesis and evaluation of a series of novel 2,3-dihydro-1H-pyrrolo[3,2,1-ij]quinazolin-1-ones for in vitro cytotoxicity against three human cancer cell lines as well as for potential antimalarial activity against the chloroquine-sensitive strain 3D7 of Plasmodium falciparum. The title compounds were prepared via PdCl2-mediated endo-dig cyclization of 2-aryl-8-(arylethynyl-6-bromo-2,3-dihydroquinazolin-4(1H-ones. The latter were prepared, in turn, via initial Sonogashira cross-coupling of 2-amino-5-bromo-3-iodobenzamide with aryl acetylenes followed by boric acid-mediated cyclocondensation of the intermediate 2-amino-3-(arylethynyl-5-bromobenzamides with benzaldehyde derivatives. The 2,3-dihydro-1H-pyrrolo[3,2,1-ij]quinazolin-1-ones 4a–k were evaluated for potential in vitro cytotoxicity against the breast (MCF-7, melanoma (B16 and endothelioma (sEnd.2 cell lines. All of the compounds except 4h and 4i were found to be inactive against the three cancer cell lines. Compound 4h substituted with a 4-methoxyphenyl and 4-fluorophenyl groups at the 3- and 5-positions was found to exhibit significant cytotoxicity against the three cancer cell lines. The presence of phenyl and 3-chlorophenyl groups at the 3- and 5-posiitons of the pyrroloquinazolinone 4i, on the other hand, resulted in significant cytotoxicity against vascular tumour endothelial cells (sEnd.2, but reduced activity against the melanoma (B16 and breast cancer (MCF-7 cells except at higher concentrations. The 2,3-dihydro-1H-pyrrolo[3,2,1-ij]quinazolin-1-ones 4a–l were found to be inactive against the chloroquine sensitive 3D7 strain of Plasmodium falciparum.

  20. Evaluation of MAP-specific peptides following vaccination of goats

    DEFF Research Database (Denmark)

    Lybeck, Kari; Sjurseth, Siri K.; Melvang, Heidi Mikkelsen

    species or 2) selected based on “experience”. Peptides predicted to bind bovine MHC II by in silico analysis were included in further studies, resulting in two panels 1) genome-based and 2) selected. Initially, two groups of 15 healthy goats were vaccinated with one of the two panels (50 µg/peptide in CAF......01 adjuvant/CAF04 for boosting). Four MAP-infected goats were also vaccinated. In a second vaccination trail, groups of 8 healthy goat kids were vaccinated with genome-based peptides, selected peptides or selected peptides linked together in a recombinant protein (20 µg/peptide or 50 µg protein...... peptides. IFN-γ responses in healthy goats after the first vaccination were low, but testing of T cell lines from MAP-infected goats identified peptides inducing strong proliferative responses. Peptides for a second vaccination were selected by combining results from this study with a parallel cattle study...

  1. A microbially derived tyrosine-sulfated peptide mimics a plant peptide hormone.

    Science.gov (United States)

    Pruitt, Rory N; Joe, Anna; Zhang, Weiguo; Feng, Wei; Stewart, Valley; Schwessinger, Benjamin; Dinneny, José R; Ronald, Pamela C

    2017-07-01

    The biotrophic pathogen Xanthomonas oryzae pv. oryzae (Xoo) produces a sulfated peptide named RaxX, which shares similarity to peptides in the PSY (plant peptide containing sulfated tyrosine) family. We hypothesize that RaxX mimics the growth-stimulating activity of PSY peptides. Root length was measured in Arabidopsis and rice treated with synthetic RaxX peptides. We also used comparative genomic analyses and reactive oxygen species burst assays to evaluate the activity of RaxX and PSY peptides. Here we found that a synthetic sulfated RaxX derivative comprising 13 residues (RaxX13-sY), highly conserved between RaxX and PSY, induces root growth in Arabidopsis and rice in a manner similar to that triggered by PSY. We identified residues that are required for activation of immunity mediated by the rice XA21 receptor but that are not essential for root growth induced by PSY. Finally, we showed that a Xanthomonas strain lacking raxX is impaired in virulence. These findings suggest that RaxX serves as a molecular mimic of PSY peptides to facilitate Xoo infection and that XA21 has evolved the ability to recognize and respond specifically to the microbial form of the peptide. © 2017 UT-Battelle LLC. New Phytologist © 2017 New Phytologist Trust.

  2. Two group A streptococcal peptide pheromones act through opposing Rgg regulators to control biofilm development.

    Directory of Open Access Journals (Sweden)

    Jennifer C Chang

    2011-08-01

    Full Text Available Streptococcus pyogenes (Group A Streptococcus, GAS is an important human commensal that occasionally causes localized infections and less frequently causes severe invasive disease with high mortality rates. How GAS regulates expression of factors used to colonize the host and avoid immune responses remains poorly understood. Intercellular communication is an important means by which bacteria coordinate gene expression to defend against host assaults and competing bacteria, yet no conserved cell-to-cell signaling system has been elucidated in GAS. Encoded within the GAS genome are four rgg-like genes, two of which (rgg2 and rgg3 have no previously described function. We tested the hypothesis that rgg2 or rgg3 rely on extracellular peptides to control target-gene regulation. We found that Rgg2 and Rgg3 together tightly regulate two linked genes encoding new peptide pheromones. Rgg2 activates transcription of and is required for full induction of the pheromone genes, while Rgg3 plays an antagonistic role and represses pheromone expression. The active pheromone signals, termed SHP2 and SHP3, are short and hydrophobic (DI[I/L]IIVGG, and, though highly similar in sequence, their ability to disrupt Rgg3-DNA complexes were observed to be different, indicating that specificity and differential activation of promoters are characteristics of the Rgg2/3 regulatory circuit. SHP-pheromone signaling requires an intact oligopeptide permease (opp and a metalloprotease (eep, supporting the model that pro-peptides are secreted, processed to the mature form, and subsequently imported to the cytoplasm to interact directly with the Rgg receptors. At least one consequence of pheromone stimulation of the Rgg2/3 pathway is increased biogenesis of biofilms, which counteracts negative regulation of biofilms by RopB (Rgg1. These data provide the first demonstration that Rgg-dependent quorum sensing functions in GAS and substantiate the role that Rggs play as peptide

  3. Oxyntomodulin differentially affects glucagon-like peptide-1 receptor beta-arrestin recruitment and signaling through Galpha(s)

    DEFF Research Database (Denmark)

    Jorgensen, Rasmus; Kubale, Valentina; Vrecl, Milka

    2007-01-01

    The glucagon-like peptide (GLP)-1 receptor is a promising target for the treatment of type 2 diabetes and obesity, and there is great interest in characterizing the pharmacology of the GLP-1 receptor and its ligands. In the present report, we have applied bioluminescence resonance energy transfer...

  4. Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion

    DEFF Research Database (Denmark)

    Witte, Anne-Barbara; Grybäck, Per; Jacobsson, Hans

    2011-01-01

    Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma ...

  5. Identification of the IGF-1 processing product human Ec/rodent Eb peptide in various tissues: Evidence for its differential regulation after exercise-induced muscle damage in humans.

    Science.gov (United States)

    Vassilakos, George; Philippou, Anastassios; Koutsilieris, Michael

    2017-02-01

    Insulin-like growth factor-1 (IGF-1) is a pleiotropic factor expressed in various tissues and plays a critical role in skeletal muscle physiology. Alternative splicing of the IGF-1 gene gives rise to different precursor polypeptides (isoforms) which could undergo post-translational cleavage, generating the common mature IGF-1 peptide and different carboxyl terminal extension (E-) peptides, with the fate of the latter being, so far, unknown. The objective if this study was to identify the IGF-1Ec forms or processing product(s), other than mature IGF-1, generated in different human and rodent tissues and particularly in human skeletal muscle after exercise-induced damage. Protein lysates from a wide range of human and rodent tissues were immunoblotted with a rabbit anti-human Ec polyclonal antibody raised against the last 24 amino acids of the C-terminal of the Ec peptide. This antibody can recognize the Ec peptide, both as part of IGF-1Ec and alone, and also the corresponding rodent forms, due to the high homology that the human Ec shares with the rodent Eb. We were able to confirm, for the first time, that the human Ec peptide and its rodent homologous Eb peptide are produced simultaneously with their precursor protein (pro-IGF-1Ec/Eb) in vivo, in a wide range of tissues (e.g. muscle, liver, heart). Proprotein convertase furin digestion of human muscle and liver protein lysates confirmed that the higher molecular form, pro-IGF-1Ec, can be cleaved to produce the free Ec peptide. Furthermore, initial evidence is provided that Ec peptide is differentially regulated during the process of muscle regeneration after exercise-induced damage in humans. The findings of this study possibly imply that the post-translational modification of the IGF-1Ec pro-peptide may regulate the bioavailability and activity of the processing product(s). Copyright © 2016. Published by Elsevier Ltd.

  6. Mathematical Modeling of Interacting Glucose-Sensing Mechanisms and Electrical Activity Underlying Glucagon-Like Peptide 1 Secretion.

    Directory of Open Access Journals (Sweden)

    Michela Riz

    2015-12-01

    Full Text Available Intestinal L-cells sense glucose and other nutrients, and in response release glucagon-like peptide 1 (GLP-1, peptide YY and other hormones with anti-diabetic and weight-reducing effects. The stimulus-secretion pathway in L-cells is still poorly understood, although it is known that GLP-1 secreting cells use sodium-glucose co-transporters (SGLT and ATP-sensitive K+-channels (K(ATP-channels to sense intestinal glucose levels. Electrical activity then transduces glucose sensing to Ca2+-stimulated exocytosis. This particular glucose-sensing arrangement with glucose triggering both a depolarizing SGLT current as well as leading to closure of the hyperpolarizing K(ATP current is of more general interest for our understanding of glucose-sensing cells. To dissect the interactions of these two glucose-sensing mechanisms, we build a mathematical model of electrical activity underlying GLP-1 secretion. Two sets of model parameters are presented: one set represents primary mouse colonic L-cells; the other set is based on data from the GLP-1 secreting GLUTag cell line. The model is then used to obtain insight into the differences in glucose-sensing between primary L-cells and GLUTag cells. Our results illuminate how the two glucose-sensing mechanisms interact, and suggest that the depolarizing effect of SGLT currents is modulated by K(ATP-channel activity. Based on our simulations, we propose that primary L-cells encode the glucose signal as changes in action potential amplitude, whereas GLUTag cells rely mainly on frequency modulation. The model should be useful for further basic, pharmacological and theoretical investigations of the cellular signals underlying endogenous GLP-1 and peptide YY release.

  7. The Involvement of miR-23a/APAF1 Regulation Axis in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Fung Lin Yong

    2014-07-01

    Full Text Available Recent advances in microRNAome have made microRNAs (miRNAs a compelling novel class of biomarker in cancer biology. In the present study, the role of miR-23a in the carcinogenesis of colorectal cancer (CRC was investigated. Cell viability, apoptosis, and caspase 3/7 activation analyses were conducted to determine the potentiality of apoptosis resistance function of miR-23a in CRC. Luciferase assay was performed to verify a putative target site of miR-23a in the 3'-UTR of apoptosis protease activating factor 1 (APAF1 mRNA. The expression levels of miR-23a and APAF1 in CRC cell lines (SW480 and SW620 and clinical samples were assessed using reverse transcription-quantitative real-time PCR (RT-qPCR and Western blot. We found that the inhibition of miR-23a in SW480 and SW620 cell lines resulted in significant reduction of cell viability and promotion of cell apoptosis. Moreover, miR-23a up-regulation was coupled with APAF1 down-regulation in CRC tissue samples. Taken together, miR-23a was identified to regulate apoptosis in CRC. Our study highlights the potential application of miR-23a/APAF1 regulation axis in miRNA-based therapy and prognostication.

  8. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  9. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  10. Mixture-based combinatorial libraries from small individual peptide libraries: a case study on α1-antitrypsin deficiency.

    Science.gov (United States)

    Chang, Yi-Pin; Chu, Yen-Ho

    2014-05-16

    The design, synthesis and screening of diversity-oriented peptide libraries using a "libraries from libraries" strategy for the development of inhibitors of α1-antitrypsin deficiency are described. The major buttress of the biochemical approach presented here is the use of well-established solid-phase split-and-mix method for the generation of mixture-based libraries. The combinatorial technique iterative deconvolution was employed for library screening. While molecular diversity is the general consideration of combinatorial libraries, exquisite design through systematic screening of small individual libraries is a prerequisite for effective library screening and can avoid potential problems in some cases. This review will also illustrate how large peptide libraries were designed, as well as how a conformation-sensitive assay was developed based on the mechanism of the conformational disease. Finally, the combinatorially selected peptide inhibitor capable of blocking abnormal protein aggregation will be characterized by biophysical, cellular and computational methods.

  11. Exendin-4, but not glucagon-like peptide-1, is cleared exclusively by glomerular filtration in anaesthetised pigs

    DEFF Research Database (Denmark)

    Simonsen, L; Holst, Jens Juul; Deacon, C F

    2006-01-01

    AIMS/HYPOTHESIS: The insulinotropic hormone, glucagon-like peptide-1 (GLP-1), is rapidly degraded in vivo as a result of the combination of extensive enzymatic degradation and renal extraction. The GLP-1 receptor agonist, exendin-4, has a longer duration of action, and has recently been approved ...

  12. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  13. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... or an amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  14. Glucagon-like peptide 1 inhibition of gastric emptying outweighs its insulinotropic effects in healthy humans

    DEFF Research Database (Denmark)

    Nauck, M A; Niedereichholz, U; Ettler, R

    1997-01-01

    Glucagon-like peptide 1 (GLP-1) has been shown to inhibit gastric emptying of liquid meals in type 2 diabetic patients. It was the aim of the present study to compare the action of physiological and pharmacological doses of intravenous GLP-1-(7-36) amide and GLP-1-(7-37) on gastric emptying...... (0-240 min), integrated incremental glucose (P inhibits gastric emptying also in normal subjects, 2) physiological doses (0.4 pmol.kg-1.min-1) still have...

  15. Circulating levels of vasoactive peptides in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Strauss, Gitte Irene; Tofteng, Flemming

    2009-01-01

    PURPOSE: The underlying mechanisms for cerebral blood flow (CBF) abnormalities in acute bacterial meningitis (ABM) are largely unknown. Putative mediators include vasoactive peptides, e.g. calcitonin-gene related peptide (CGRP), vasoactive intestinal peptide (VIP), and endothelin-1 (ET-1), all...

  16. Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

    Science.gov (United States)

    Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

    2015-10-01

    The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

  17. The major genetic determinants of HIV-1 control affect HLA class I peptide presentation.

    Science.gov (United States)

    Pereyra, Florencia; Jia, Xiaoming; McLaren, Paul J; Telenti, Amalio; de Bakker, Paul I W; Walker, Bruce D; Ripke, Stephan; Brumme, Chanson J; Pulit, Sara L; Carrington, Mary; Kadie, Carl M; Carlson, Jonathan M; Heckerman, David; Graham, Robert R; Plenge, Robert M; Deeks, Steven G; Gianniny, Lauren; Crawford, Gabriel; Sullivan, Jordan; Gonzalez, Elena; Davies, Leela; Camargo, Amy; Moore, Jamie M; Beattie, Nicole; Gupta, Supriya; Crenshaw, Andrew; Burtt, Noël P; Guiducci, Candace; Gupta, Namrata; Gao, Xiaojiang; Qi, Ying; Yuki, Yuko; Piechocka-Trocha, Alicja; Cutrell, Emily; Rosenberg, Rachel; Moss, Kristin L; Lemay, Paul; O'Leary, Jessica; Schaefer, Todd; Verma, Pranshu; Toth, Ildiko; Block, Brian; Baker, Brett; Rothchild, Alissa; Lian, Jeffrey; Proudfoot, Jacqueline; Alvino, Donna Marie L; Vine, Seanna; Addo, Marylyn M; Allen, Todd M; Altfeld, Marcus; Henn, Matthew R; Le Gall, Sylvie; Streeck, Hendrik; Haas, David W; Kuritzkes, Daniel R; Robbins, Gregory K; Shafer, Robert W; Gulick, Roy M; Shikuma, Cecilia M; Haubrich, Richard; Riddler, Sharon; Sax, Paul E; Daar, Eric S; Ribaudo, Heather J; Agan, Brian; Agarwal, Shanu; Ahern, Richard L; Allen, Brady L; Altidor, Sherly; Altschuler, Eric L; Ambardar, Sujata; Anastos, Kathryn; Anderson, Ben; Anderson, Val; Andrady, Ushan; Antoniskis, Diana; Bangsberg, David; Barbaro, Daniel; Barrie, William; Bartczak, J; Barton, Simon; Basden, Patricia; Basgoz, Nesli; Bazner, Suzane; Bellos, Nicholaos C; Benson, Anne M; Berger, Judith; Bernard, Nicole F; Bernard, Annette M; Birch, Christopher; Bodner, Stanley J; Bolan, Robert K; Boudreaux, Emilie T; Bradley, Meg; Braun, James F; Brndjar, Jon E; Brown, Stephen J; Brown, Katherine; Brown, Sheldon T; Burack, Jedidiah; Bush, Larry M; Cafaro, Virginia; Campbell, Omobolaji; Campbell, John; Carlson, Robert H; Carmichael, J Kevin; Casey, Kathleen K; Cavacuiti, Chris; Celestin, Gregory; Chambers, Steven T; Chez, Nancy; Chirch, Lisa M; Cimoch, Paul J; Cohen, Daniel; Cohn, Lillian E; Conway, Brian; Cooper, David A; Cornelson, Brian; Cox, David T; Cristofano, Michael V; Cuchural, George; Czartoski, Julie L; Dahman, Joseph M; Daly, Jennifer S; Davis, Benjamin T; Davis, Kristine; Davod, Sheila M; DeJesus, Edwin; Dietz, Craig A; Dunham, Eleanor; Dunn, Michael E; Ellerin, Todd B; Eron, Joseph J; Fangman, John J W; Farel, Claire E; Ferlazzo, Helen; Fidler, Sarah; Fleenor-Ford, Anita; Frankel, Renee; Freedberg, Kenneth A; French, Neel K; Fuchs, Jonathan D; Fuller, Jon D; Gaberman, Jonna; Gallant, Joel E; Gandhi, Rajesh T; Garcia, Efrain; Garmon, Donald; Gathe, Joseph C; Gaultier, Cyril R; Gebre, Wondwoosen; Gilman, Frank D; Gilson, Ian; Goepfert, Paul A; Gottlieb, Michael S; Goulston, Claudia; Groger, Richard K; Gurley, T Douglas; Haber, Stuart; Hardwicke, Robin; Hardy, W David; Harrigan, P Richard; Hawkins, Trevor N; Heath, Sonya; Hecht, Frederick M; Henry, W Keith; Hladek, Melissa; Hoffman, Robert P; Horton, James M; Hsu, Ricky K; Huhn, Gregory D; Hunt, Peter; Hupert, Mark J; Illeman, Mark L; Jaeger, Hans; Jellinger, Robert M; John, Mina; Johnson, Jennifer A; Johnson, Kristin L; Johnson, Heather; Johnson, Kay; Joly, Jennifer; Jordan, Wilbert C; Kauffman, Carol A; Khanlou, Homayoon; Killian, Robert K; Kim, Arthur Y; Kim, David D; Kinder, Clifford A; Kirchner, Jeffrey T; Kogelman, Laura; Kojic, Erna Milunka; Korthuis, P Todd; Kurisu, Wayne; Kwon, Douglas S; LaMar, Melissa; Lampiris, Harry; Lanzafame, Massimiliano; Lederman, Michael M; Lee, David M; Lee, Jean M L; Lee, Marah J; Lee, Edward T Y; Lemoine, Janice; Levy, Jay A; Llibre, Josep M; Liguori, Michael A; Little, Susan J; Liu, Anne Y; Lopez, Alvaro J; Loutfy, Mono R; Loy, Dawn; Mohammed, Debbie Y; Man, Alan; Mansour, Michael K; Marconi, Vincent C; Markowitz, Martin; Marques, Rui; Martin, Jeffrey N; Martin, Harold L; Mayer, Kenneth Hugh; McElrath, M Juliana; McGhee, Theresa A; McGovern, Barbara H; McGowan, Katherine; McIntyre, Dawn; Mcleod, Gavin X; Menezes, Prema; Mesa, Greg; Metroka, Craig E; Meyer-Olson, Dirk; Miller, Andy O; Montgomery, Kate; Mounzer, Karam C; Nagami, Ellen H; Nagin, Iris; Nahass, Ronald G; Nelson, Margret O; Nielsen, Craig; Norene, David L; O'Connor, David H; Ojikutu, Bisola O; Okulicz, Jason; Oladehin, Olakunle O; Oldfield, Edward C; Olender, Susan A; Ostrowski, Mario; Owen, William F; Pae, Eunice; Parsonnet, Jeffrey; Pavlatos, Andrew M; Perlmutter, Aaron M; Pierce, Michael N; Pincus, Jonathan M; Pisani, Leandro; Price, Lawrence Jay; Proia, Laurie; Prokesch, Richard C; Pujet, Heather Calderon; Ramgopal, Moti; Rathod, Almas; Rausch, Michael; Ravishankar, J; Rhame, Frank S; Richards, Constance Shamuyarira; Richman, Douglas D; Rodes, Berta; Rodriguez, Milagros; Rose, Richard C; Rosenberg, Eric S; Rosenthal, Daniel; Ross, Polly E; Rubin, David S; Rumbaugh, Elease; Saenz, Luis; Salvaggio, Michelle R; Sanchez, William C; Sanjana, Veeraf M; Santiago, Steven; Schmidt, Wolfgang; Schuitemaker, Hanneke; Sestak, Philip M; Shalit, Peter; Shay, William; Shirvani, Vivian N; Silebi, Vanessa I; Sizemore, James M; Skolnik, Paul R; Sokol-Anderson, Marcia; Sosman, James M; Stabile, Paul; Stapleton, Jack T; Starrett, Sheree; Stein, Francine; Stellbrink, Hans-Jurgen; Sterman, F Lisa; Stone, Valerie E; Stone, David R; Tambussi, Giuseppe; Taplitz, Randy A; Tedaldi, Ellen M; Telenti, Amalio; Theisen, William; Torres, Richard; Tosiello, Lorraine; Tremblay, Cecile; Tribble, Marc A; Trinh, Phuong D; Tsao, Alice; Ueda, Peggy; Vaccaro, Anthony; Valadas, Emilia; Vanig, Thanes J; Vecino, Isabel; Vega, Vilma M; Veikley, Wenoah; Wade, Barbara H; Walworth, Charles; Wanidworanun, Chingchai; Ward, Douglas J; Warner, Daniel A; Weber, Robert D; Webster, Duncan; Weis, Steve; Wheeler, David A; White, David J; Wilkins, Ed; Winston, Alan; Wlodaver, Clifford G; van't Wout, Angelique; Wright, David P; Yang, Otto O; Yurdin, David L; Zabukovic, Brandon W; Zachary, Kimon C; Zeeman, Beth; Zhao, Meng

    2010-12-10

    Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

  18. The Major Genetic Determinants of HIV-1 Control Affect HLA Class I Peptide Presentation

    Science.gov (United States)

    Pereyra, Florencia; Jia, Xiaoming; McLaren, Paul J.; Telenti, Amalio; de Bakker, Paul I.W.; Walker, Bruce D.; Jia, Xiaoming; McLaren, Paul J.; Ripke, Stephan; Brumme, Chanson J.; Pulit, Sara L.; Telenti, Amalio; Carrington, Mary; Kadie, Carl M.; Carlson, Jonathan M.; Heckerman, David; de Bakker, Paul I.W.; Pereyra, Florencia; de Bakker, Paul I.W.; Graham, Robert R.; Plenge, Robert M.; Deeks, Steven G.; Walker, Bruce D.; Gianniny, Lauren; Crawford, Gabriel; Sullivan, Jordan; Gonzalez, Elena; Davies, Leela; Camargo, Amy; Moore, Jamie M.; Beattie, Nicole; Gupta, Supriya; Crenshaw, Andrew; Burtt, Noël P.; Guiducci, Candace; Gupta, Namrata; Carrington, Mary; Gao, Xiaojiang; Qi, Ying; Yuki, Yuko; Pereyra, Florencia; Piechocka-Trocha, Alicja; Cutrell, Emily; Rosenberg, Rachel; Moss, Kristin L.; Lemay, Paul; O’Leary, Jessica; Schaefer, Todd; Verma, Pranshu; Toth, Ildiko; Block, Brian; Baker, Brett; Rothchild, Alissa; Lian, Jeffrey; Proudfoot, Jacqueline; Alvino, Donna Marie L.; Vine, Seanna; Addo, Marylyn M.; Allen, Todd M.; Altfeld, Marcus; Henn, Matthew R.; Le Gall, Sylvie; Streeck, Hendrik; Walker, Bruce D.; Haas, David W.; Kuritzkes, Daniel R.; Robbins, Gregory K.; Shafer, Robert W.; Gulick, Roy M.; Shikuma, Cecilia M.; Haubrich, Richard; Riddler, Sharon; Sax, Paul E.; Daar, Eric S.; Ribaudo, Heather J.; Agan, Brian; Agarwal, Shanu; Ahern, Richard L.; Allen, Brady L.; Altidor, Sherly; Altschuler, Eric L.; Ambardar, Sujata; Anastos, Kathryn; Anderson, Ben; Anderson, Val; Andrady, Ushan; Antoniskis, Diana; Bangsberg, David; Barbaro, Daniel; Barrie, William; Bartczak, J.; Barton, Simon; Basden, Patricia; Basgoz, Nesli; Bazner, Suzane; Bellos, Nicholaos C.; Benson, Anne M.; Berger, Judith; Bernard, Nicole F.; Bernard, Annette M.; Birch, Christopher; Bodner, Stanley J.; Bolan, Robert K.; Boudreaux, Emilie T.; Bradley, Meg; Braun, James F.; Brndjar, Jon E.; Brown, Stephen J.; Brown, Katherine; Brown, Sheldon T.; Burack, Jedidiah; Bush, Larry M.; Cafaro, Virginia; Campbell, Omobolaji; Campbell, John; Carlson, Robert H.; Carmichael, J. Kevin; Casey, Kathleen K.; Cavacuiti, Chris; Celestin, Gregory; Chambers, Steven T.; Chez, Nancy; Chirch, Lisa M.; Cimoch, Paul J.; Cohen, Daniel; Cohn, Lillian E.; Conway, Brian; Cooper, David A.; Cornelson, Brian; Cox, David T.; Cristofano, Michael V.; Cuchural, George; Czartoski, Julie L.; Dahman, Joseph M.; Daly, Jennifer S.; Davis, Benjamin T.; Davis, Kristine; Davod, Sheila M.; Deeks, Steven G.; DeJesus, Edwin; Dietz, Craig A.; Dunham, Eleanor; Dunn, Michael E.; Ellerin, Todd B.; Eron, Joseph J.; Fangman, John J.W.; Farel, Claire E.; Ferlazzo, Helen; Fidler, Sarah; Fleenor-Ford, Anita; Frankel, Renee; Freedberg, Kenneth A.; French, Neel K.; Fuchs, Jonathan D.; Fuller, Jon D.; Gaberman, Jonna; Gallant, Joel E.; Gandhi, Rajesh T.; Garcia, Efrain; Garmon, Donald; Gathe, Joseph C.; Gaultier, Cyril R.; Gebre, Wondwoosen; Gilman, Frank D.; Gilson, Ian; Goepfert, Paul A.; Gottlieb, Michael S.; Goulston, Claudia; Groger, Richard K.; Gurley, T. Douglas; Haber, Stuart; Hardwicke, Robin; Hardy, W. David; Harrigan, P. Richard; Hawkins, Trevor N.; Heath, Sonya; Hecht, Frederick M.; Henry, W. Keith; Hladek, Melissa; Hoffman, Robert P.; Horton, James M.; Hsu, Ricky K.; Huhn, Gregory D.; Hunt, Peter; Hupert, Mark J.; Illeman, Mark L.; Jaeger, Hans; Jellinger, Robert M.; John, Mina; Johnson, Jennifer A.; Johnson, Kristin L.; Johnson, Heather; Johnson, Kay; Joly, Jennifer; Jordan, Wilbert C.; Kauffman, Carol A.; Khanlou, Homayoon; Killian, Robert K.; Kim, Arthur Y.; Kim, David D.; Kinder, Clifford A.; Kirchner, Jeffrey T.; Kogelman, Laura; Kojic, Erna Milunka; Korthuis, P. Todd; Kurisu, Wayne; Kwon, Douglas S.; LaMar, Melissa; Lampiris, Harry; Lanzafame, Massimiliano; Lederman, Michael M.; Lee, David M.; Lee, Jean M.L.; Lee, Marah J.; Lee, Edward T.Y.; Lemoine, Janice; Levy, Jay A.; Llibre, Josep M.; Liguori, Michael A.; Little, Susan J.; Liu, Anne Y.; Lopez, Alvaro J.; Loutfy, Mono R.; Loy, Dawn; Mohammed, Debbie Y.; Man, Alan; Mansour, Michael K.; Marconi, Vincent C.; Markowitz, Martin; Marques, Rui; Martin, Jeffrey N.; Martin, Harold L.; Mayer, Kenneth Hugh; McElrath, M. Juliana; McGhee, Theresa A.; McGovern, Barbara H.; McGowan, Katherine; McIntyre, Dawn; Mcleod, Gavin X.; Menezes, Prema; Mesa, Greg; Metroka, Craig E.; Meyer-Olson, Dirk; Miller, Andy O.; Montgomery, Kate; Mounzer, Karam C.; Nagami, Ellen H.; Nagin, Iris; Nahass, Ronald G.; Nelson, Margret O.; Nielsen, Craig; Norene, David L.; O’Connor, David H.; Ojikutu, Bisola O.; Okulicz, Jason; Oladehin, Olakunle O.; Oldfield, Edward C.; Olender, Susan A.; Ostrowski, Mario; Owen, William F.; Pae, Eunice; Parsonnet, Jeffrey; Pavlatos, Andrew M.; Perlmutter, Aaron M.; Pierce, Michael N.; Pincus, Jonathan M.; Pisani, Leandro; Price, Lawrence Jay; Proia, Laurie; Prokesch, Richard C.; Pujet, Heather Calderon; Ramgopal, Moti; Rathod, Almas; Rausch, Michael; Ravishankar, J.; Rhame, Frank S.; Richards, Constance Shamuyarira; Richman, Douglas D.; Robbins, Gregory K.; Rodes, Berta; Rodriguez, Milagros; Rose, Richard C.; Rosenberg, Eric S.; Rosenthal, Daniel; Ross, Polly E.; Rubin, David S.; Rumbaugh, Elease; Saenz, Luis; Salvaggio, Michelle R.; Sanchez, William C.; Sanjana, Veeraf M.; Santiago, Steven; Schmidt, Wolfgang; Schuitemaker, Hanneke; Sestak, Philip M.; Shalit, Peter; Shay, William; Shirvani, Vivian N.; Silebi, Vanessa I.; Sizemore, James M.; Skolnik, Paul R.; Sokol-Anderson, Marcia; Sosman, James M.; Stabile, Paul; Stapleton, Jack T.; Starrett, Sheree; Stein, Francine; Stellbrink, Hans-Jurgen; Sterman, F. Lisa; Stone, Valerie E.; Stone, David R.; Tambussi, Giuseppe; Taplitz, Randy A.; Tedaldi, Ellen M.; Telenti, Amalio; Theisen, William; Torres, Richard; Tosiello, Lorraine; Tremblay, Cecile; Tribble, Marc A.; Trinh, Phuong D.; Tsao, Alice; Ueda, Peggy; Vaccaro, Anthony; Valadas, Emilia; Vanig, Thanes J.; Vecino, Isabel; Vega, Vilma M.; Veikley, Wenoah; Wade, Barbara H.; Walworth, Charles; Wanidworanun, Chingchai; Ward, Douglas J.; Warner, Daniel A.; Weber, Robert D.; Webster, Duncan; Weis, Steve; Wheeler, David A.; White, David J.; Wilkins, Ed; Winston, Alan; Wlodaver, Clifford G.; Wout, Angelique van’t; Wright, David P.; Yang, Otto O.; Yurdin, David L.; Zabukovic, Brandon W.; Zachary, Kimon C.; Zeeman, Beth; Zhao, Meng

    2011-01-01

    Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA–viral peptide interaction as the major factor modulating durable control of HIV infection. PMID:21051598

  19. Skim Milk, Whey, and Casein Increase Body Weight and Whey and Casein Increase the Plasma C-Peptide Concentration in Overweight Adolescents12

    DEFF Research Database (Denmark)

    Arnberg, Karina; Mølgaard, Christian; Michaelsen, Kim Fleischer

    2012-01-01

    insulin, and insulin secretion estimated as the plasma C-peptide concentration in overweight adolescents. Overweight adolescents (n = 203) aged 12–15 y with a BMI of 25.4 ± 2.3 kg/m2 (mean ± SD) were randomized to 1 L/d of skim milk, whey, casein, or water for 12 wk. All milk drinks contained 35 g protein....... Outcomes were BMI-for-age Z-scores (BAZs), waist circumference, plasma insulin, homeostatic model assessment, and plasma C-peptide. We found no change in BAZ in the pretest control and water groups, whereas it was greater at 12 wk in the skim milk, whey, and casein groups compared with baseline...... and with the water and pretest control groups. The plasma C-peptide concentration increased from baseline to wk 12 in the whey and casein groups and increments were greater than in the pretest control (P

  20. Layer-by-layer films containing peptides of the Cry1Ab16 toxin from Bacillus thuringiensis for potential biotechnological applications

    International Nuclear Information System (INIS)

    Plácido, Alexandra; Oliveira Farias, Emanuel Airton de; Marani, Mariela M.; Vasconcelos, Andreanne G.; Mafud, Ana C.; Mascarenhas, Yvonne P.; Eiras, Carla

    2016-01-01

    Cry1Ab16 is a toxin of crystalline insecticidal proteins that has been widely used in genetically modified organisms (GMOs) to gain resistance to pests. For the first time, in this study, peptides derived from the immunogenic Cry1Ab16 toxin (from Bacillus thuringiensis) were immobilized as layer-by-layer (LbL) films. Given the concern about food and environmental safety, a peptide with immunogenic potential, PcL342–354C, was selected for characterization of the electrochemical, optical, and morphological properties. The results obtained by cyclic voltammetry (CV) showed that the peptide have an irreversible oxidation process in electrolyte of 0.1 mol·L"−"1 potassium phosphate buffer (PBS) at pH 7.2. It was also observed that the electrochemical response of the peptide is governed mainly by charge transfer. In an attempt to maximize the electrochemical signal of peptide, it was intercalated with natural (agar, alginate and chitosan) or synthetic polymers (polyethylenimine (PEI) and poly(sodium 4-styrenesulfonate (PSS)). The presence of synthetic polymers on the film increased the electrochemical signal of PcL342–354C up to 100 times. Images by Atomic Force Microscopy (AFM) showed that the immobilized PcL342–354C formed self-assembled nanofibers with diameters ranging from 100 to 200 nm on the polymeric film. By UV–Visible spectroscopy (UV–Vis) it was observed that the ITO/PEI/PSS/PcL342–354C film grows linearly up to the fifth layer, thereafter tending to saturation. X-ray diffraction confirmed the presence on the films of crystalline ITO and amorphous polypeptide phases. In general, the ITO/PEI/PSS/PcL342–354C film characterization proved that this system is an excellent candidate for applications in electrochemical sensors and other biotechnological applications for GMOs and environmental indicators. - Highlights: • Peptides of the Cry1Ab16 toxin for potential biotechnological applications • Optimized LbL film deposition for synergic