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Sample records for peptide derivatives probes

  1. Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe

    International Nuclear Information System (INIS)

    Sugawara, Kazuharu; Shinohara, Hiroki; Kadoya, Toshihiko; Kuramitz, Hideki

    2016-01-01

    To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y_4). A peptide whereby Y_4C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH_2) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY_4C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye. - Highlights: • We constructed a multifunctional peptide probe for the electrochemical sensing of lymphoma cells. • The peptide probe consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. • The electrode response of the peptide probe changes due to selective uptake into the cells.

  2. Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Kazuharu, E-mail: kzsuga@maebashi-it.ac.jp [Maebashi Institute of Technology, Gunma 371-0816 (Japan); Shinohara, Hiroki; Kadoya, Toshihiko [Maebashi Institute of Technology, Gunma 371-0816 (Japan); Kuramitz, Hideki [Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555 (Japan)

    2016-06-14

    To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y{sub 4}). A peptide whereby Y{sub 4}C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH{sub 2}) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY{sub 4}C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye. - Highlights: • We constructed a multifunctional peptide probe for the electrochemical sensing of lymphoma cells. • The peptide probe consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. • The electrode response of the peptide probe changes due to selective uptake into the cells.

  3. A fluorescent glycolipid-binding peptide probe traces cholesterol dependent microdomain-derived trafficking pathways.

    Directory of Open Access Journals (Sweden)

    Steffen Steinert

    Full Text Available BACKGROUND: The uptake and intracellular trafficking of sphingolipids, which self-associate into plasma membrane microdomains, is associated with many pathological conditions, including viral and toxin infection, lipid storage disease, and neurodegenerative disease. However, the means available to label the trafficking pathways of sphingolipids in live cells are extremely limited. In order to address this problem, we have developed an exogenous, non-toxic probe consisting of a 25-amino acid sphingolipid binding domain, the SBD, derived from the amyloid peptide Abeta, and conjugated by a neutral linker with an organic fluorophore. The current work presents the characterization of the sphingolipid binding and live cell trafficking of this novel probe, the SBD peptide. SBD was the name given to a motif originally recognized by Fantini et al in a number of glycolipid-associated proteins, and was proposed to interact with sphingolipids in membrane microdomains. METHODOLOGY/PRINCIPAL FINDINGS: In accordance with Fantini's model, optimal SBD binding to membranes depends on the presence of sphingolipids and cholesterol. In synthetic membrane binding assays, SBD interacts preferentially with raft-like lipid mixtures containing sphingomyelin, cholesterol, and complex gangliosides in a pH-dependent manner, but is less glycolipid-specific than Cholera toxin B (CtxB. Using quantitative time-course colocalization in live cells, we show that the uptake and intracellular trafficking route of SBD is unlike that of either the non-raft marker Transferrin or the raft markers CtxB and Flotillin2-GFP. However, SBD traverses an endolysosomal route that partially intersects with raft-associated pathways, with a major portion being diverted at a late time point to rab11-positive recycling endosomes. Trafficking of SBD to acidified compartments is strongly disrupted by cholesterol perturbations, consistent with the regulation of sphingolipid trafficking by cholesterol

  4. Cyanine-based probe\\tag-peptide pair fluorescence protein imaging and fluorescence protein imaging methods

    Science.gov (United States)

    Mayer-Cumblidge, M. Uljana; Cao, Haishi

    2013-01-15

    A molecular probe comprises two arsenic atoms and at least one cyanine based moiety. A method of producing a molecular probe includes providing a molecule having a first formula, treating the molecule with HgOAc, and subsequently transmetallizing with AsCl.sub.3. The As is liganded to ethanedithiol to produce a probe having a second formula. A method of labeling a peptide includes providing a peptide comprising a tag sequence and contacting the peptide with a biarsenical molecular probe. A complex is formed comprising the tag sequence and the molecular probe. A method of studying a peptide includes providing a mixture containing a peptide comprising a peptide tag sequence, adding a biarsenical probe to the mixture, and monitoring the fluorescence of the mixture.

  5. 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.)

  6. Cyanine-based probe\\tag-peptide pair for fluorescence protein imaging and fluorescence protein imaging methods

    Science.gov (United States)

    Mayer-Cumblidge, M Uljana [Richland, WA; Cao, Haishi [Richland, WA

    2010-08-17

    A molecular probe comprises two arsenic atoms and at least one cyanine based moiety. A method of producing a molecular probe includes providing a molecule having a first formula, treating the molecule with HgOAc, and subsequently transmetallizing with AsCl.sub.3. The As is liganded to ethanedithiol to produce a probe having a second formula. A method of labeling a peptide includes providing a peptide comprising a tag sequence and contacting the peptide with a biarsenical molecular probe. A complex is formed comprising the tag sequence and the molecular probe. A method of studying a peptide includes providing a mixture containing a peptide comprising a peptide tag sequence, adding a biarsenical probe to the mixture, and monitoring the fluorescence of the mixture.

  7. 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.

  8. Design and expression of a short peptide as an HIV detection probe

    Energy Technology Data Exchange (ETDEWEB)

    Lines, Jamie A.; Yu, Zhiqiang; Dedkova, Larisa M.; Chen, Shengxi, E-mail: shengxi.chen.1@asu.edu

    2014-01-03

    Highlights: •We designed a short fusion peptide (FP-50) for in vivo expression. •This peptide is a very promising component for detection of gp120 protein. •The detectable level is about 20–200 times lower than previously published methods. •It is a novel probe to detect HIV-1 gp120 during early stages of HIV infection. -- Abstract: To explore a low-cost novel probe for HIV detection, we designed and prepared a 50-amino acid-length short fusion peptide (FP-50) via Escherichia coli in vivo expression. It was employed as a novel probe to detect HIV-1 gp120 protein. The detectable level of gp120 protein using the FP-50 peptide was approximately 20–200 times lower than previously published methods that used a pair of monoclonal antibodies. Thus, this short peptide is a very promising component for detection of gp120 protein during early stages of HIV infection.

  9. Grafting of a peptide probe for Prostate-Specific Antigen detection using diazonium electroreduction and click chemistry.

    Science.gov (United States)

    Strzemińska, I; Sainte Rose Fanchine, S; Anquetin, G; Reisberg, S; Noël, V; Pham, M C; Piro, B

    2016-07-15

    The main objective of this work was to validate a label-free electrochemical method of protein detection using peptides as capture probes. As a proof-of-concept, we used a 7 amino acids sequence (HSSKLQL) specific for Prostate Specific Antigen. We investigated various electrografting conditions of two anilines (2-[(4-aminophenyl)sulfanyl]-8-hydroxy-1,4-naphthoquinone and 4-azidoaniline) further converted in situ into their corresponding diazonium salts on glassy carbon electrodes. It was demonstrated that the best method to obtain a mixed layer is the simultaneous electroreduction of the two diazonium salts. 4-azidoaniline was used to covalently immobilize the ethynyl-functionalized peptide probe by click coupling, and the hydroxynaphthoquinone derivative plays the role of electrochemical transducer of the peptide-protein recognition. The proteolytic activity of PSA towards a small peptide substrate carrying streptavidin at its distal end was also investigated to design an original sensing architecture leading to a reagentless, label free, and "signal-on" PSA sensor. Without optimization, the limit of quantification can be estimated in the nM to pM range. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. A novel CXCR4-targeted near-infrared (NIR) fluorescent probe (Peptide R-NIR750) specifically detects CXCR4 expressing tumors.

    Science.gov (United States)

    Santagata, Sara; Portella, Luigi; Napolitano, Maria; Greco, Adelaide; D'Alterio, Crescenzo; Barone, Maria Vittoria; Luciano, Antonio; Gramanzini, Matteo; Auletta, Luigi; Arra, Claudio; Zannetti, Antonella; Scala, Stefania

    2017-05-31

    C-X-C chemokine receptor 4 (CXCR4) is over-expressed in multiple human cancers and correlates with tumor aggressiveness, poor prognosis and increased risk for distant metastases. Imaging agents for CXCR4 are thus highly desirable. We developed a novel CXCR4-targeted near-infrared (NIR) fluorescent probe (Peptide R-NIR750) conjugating the new developed CXCR4 peptidic antagonist Peptide R with the NIR fluorescent dye VivoTag-S750. Specific CXCR4 binding was obtained in cells overexpressing human CXCR4 (B16-hCXCR4 and human melanoma cells PES43), but not in CXCR4 low expressing cells (FB-1). Ex vivo evaluation demonstrated that PepR-NIR750 specifically detects B16-hCXCR4-derived subcutaneous tumors and lung metastases. Fluorescence Molecular Tomography (FMT) in vivo imaging was performed on mice carrying subcutaneous CHO and CHO-CXCR4 tumors. PepR-NIR750 accumulates only in CXCR4-positive expressing subcutaneous tumors. Additionally, an intense NIR fluorescence signal was detected in PES43-derived lung metastases of nude mice injected with PepR-NIR750 versus mice injected with VivoTag-S750. With a therapeutic intent, mice bearing PES43-derived lung metastases were treated with Peptide R. A the dramatic reduction in PES43-derived lung metastases was detected through a decrease of the PepR-NIR750 signal. PepR-NIR750 is a specific probe for non-invasive detection of human high CXCR4-expressing tumors and metastatic lesion and thus a valuable tool for cancer molecular imaging.

  11. Anticancer activities of bovine and human lactoferricin-derived peptides.

    Science.gov (United States)

    Arias, Mauricio; Hilchie, Ashley L; Haney, Evan F; Bolscher, Jan G M; Hyndman, M Eric; Hancock, Robert E W; Vogel, Hans J

    2017-02-01

    Lactoferrin (LF) is a mammalian host defense glycoprotein with diverse biological activities. Peptides derived from the cationic region of LF possess cytotoxic activity against cancer cells in vitro and in vivo. Bovine lactoferricin (LFcinB), a peptide derived from bovine LF (bLF), exhibits broad-spectrum anticancer activity, while a similar peptide derived from human LF (hLF) is not as active. In this work, several peptides derived from the N-terminal regions of bLF and hLF were studied for their anticancer activities against leukemia and breast-cancer cells, as well as normal peripheral blood mononuclear cells. The cyclized LFcinB-CLICK peptide, which possesses a stable triazole linkage, showed improved anticancer activity, while short peptides hLF11 and bLF10 were not cytotoxic to cancer cells. Interestingly, hLF11 can act as a cell-penetrating peptide; when combined with the antimicrobial core sequence of LFcinB (RRWQWR) through either a Pro or Gly-Gly linker, toxicity to Jurkat cells increased. Together, our work extends the library of LF-derived peptides tested for anticancer activity, and identified new chimeric peptides with high cytotoxicity towards cancerous cells. Additionally, these results support the notion that short cell-penetrating peptides and antimicrobial peptides can be combined to create new adducts with increased potency.

  12. Antihypertensive properties of lactoferricin B-derived peptides.

    Science.gov (United States)

    Ruiz-Giménez, Pedro; Ibáñez, Aida; Salom, Juan B; Marcos, Jose F; López-Díez, Jose Javier; Vallés, Salvador; Torregrosa, Germán; Alborch, Enrique; Manzanares, Paloma

    2010-06-09

    A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex vivo inhibitory effects was found. Only LfcinB(20-25) and one of its fragments, F1, generated after a simulated gastrointestinal digestion, showed significant antihypertensive effects in SHR after oral administration. Remarkably, F1 did not show any effect on ACE-dependent vasoconstriction in contrast to the inhibitory effect showed by LfcinB(20-25). In conclusion, two LfcinB-derived peptides lower blood pressure and exhibit potential as orally effective antihypertensive compounds, yet a complete elucidation of the mechanism(s) involved deserves further ongoing research.

  13. A bispecific peptide based near-infrared probe for in vivo tumor diagnosis

    Science.gov (United States)

    Ding, Li; Chen, Wei R.; Gu, Yueqing

    2013-02-01

    The epidermal growth factor receptor EGFR and HER2 are members of recepeter tyrosine kinase family. Overexpression of EGFR and HER2 has been observed in a variety of human tumors, making these receptors promising targets for tumor diagnosis. An affibody targeting HER2 and a nanobody targeting EGFR were reported before. In this Manuscript, we described an bispecific peptide combined with an affibody and a nanonbody through a linker―(G4S)3 . And the bispecific peptide was labeled with near-infrared (NIR) fluorochrome ICG-Der-02 for in vivo tumor EGFR and HER2 targeting. Afterwards, the EGFR and HER2 specificity of the fluorescent probe was tested in vitro for receptor binding assay and fluorescence microscopy and in vivo for subcutaneous MDA-MB-231 tumor targeting. The results indicated that the bispecific peptide had a high affinity to EGFR and HER2. Besides, in vitro and in vivo tumor targeting experiment indicated that the ICG-Der-02-( bispecific peptide) showed excellent tumor activity accumulation. Noninvasive NIR fluorescence imaging is able to detect tumor EGFR and HER2 expression based upon the highly potent bispecific peptide probe.

  14. Anticancer activities of bovine and human lactoferricin-derived peptides

    NARCIS (Netherlands)

    Arias, M.; Hilchie, A.L.; Haney, E.F.; Bolscher, J.G.M.; Hyndman, M.E.; Hancock, R.E.W.; Vogel, H.J.

    2017-01-01

    Lactoferrin (LF) is a mammalian host defense glycoprotein with diverse biological activities. Peptides derived from the cationic region of LF possess cytotoxic activity against cancer cells in vitro and in vivo. Bovine lactoferricin (LFcinB), a peptide derived from bovine LF (bLF), exhibits

  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. Food Derived Bioactive Peptides and Intestinal Barrier Function

    Directory of Open Access Journals (Sweden)

    Olga Martínez-Augustin

    2014-12-01

    Full Text Available A wide range of food-derived bioactive peptides have been shown to exert health-promoting actions and are therefore considered functional foods or nutraceuticals. Some of these actions are related to the maintenance, reinforcement or repairment of the intestinal barrier function (IBF whose role is to selectively allow the absorption of water, nutrients and ions while preventing the influx of microorganisms from the intestinal lumen. Alterations in the IBF have been related to many disorders, such as inflammatory bowel disease or metabolic syndrome. Components of IBF are the intestinal epithelium, the mucus layer, secretory immunoglobulin A and cells of the innate and adaptive immune systems. Here we review the effects of food derived bioactive peptides on these IBF components. In vitro and in vivo effects, both in healthy and disease states, have been reviewed. Although limited, the available information indicates a potential for food-derived peptides to modify IBF and to contribute to disease treatment, but further research is needed to better isolate responsible peptides, and to help define their mode of action.

  17. 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.

  18. Lactoferricin B-derived peptides with inhibitory effects on ECE-dependent vasoconstriction.

    Science.gov (United States)

    Fernández-Musoles, Ricardo; López-Díez, José Javier; Torregrosa, Germán; Vallés, Salvador; Alborch, Enrique; Manzanares, Paloma; Salom, Juan B

    2010-10-01

    Endothelin-converting enzyme (ECE), a key peptidase in the endothelin (ET) system, cleaves inactive big ET-1 to produce active ET-1, which binds to ET(A) receptors to exert its vasoconstrictor and pressor effects. ECE inhibition could be beneficial in the treatment of hypertension. In this study, a set of eight lactoferricin B (LfcinB)-derived peptides, previously characterized in our laboratory as angiotensin-converting enzyme (ACE) inhibitory peptides, was examined for their inhibitory effects on ECE. In vitro inhibitory effects on ECE activity were assessed using both the synthetic fluorogenic peptide substrate V (FPS V) and the natural substrate big ET-1. To study vasoactive effects, an ex vivo functional assay was developed using isolated rabbit carotid artery segments. With FPS V, only four LfcinB-derived peptides induced inhibition of ECE activity, whereas the eight peptides showed ECE inhibitory effects with big ET-1 as substrate. Regarding the ex vivo assays, six LfcinB-derived peptides showed inhibition of big ET-1-induced, ECE-dependent vasoconstriction. A positive correlation between the inhibitory effects of LfcinB-derived peptides on ECE activity when using big ET-1 and the inhibitory effects on ECE-dependent vasoconstriction was shown. ECE-independent vasoconstriction induced by ET-1 was not affected, thus discarding effects of LfcinB-derived peptides on ET(A) receptors or intracellular signal transduction mechanisms. In conclusion, a combined in vitro and ex vivo method to assess the effects of potentially antihypertensive peptides on the ET system has been developed and applied to show the inhibitory effects on ECE-dependent vasoconstriction of six LfcinB-derived peptides, five of which were dual vasopeptidase (ACE/ECE) inhibitors. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. 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.

  20. The pharmacokinetics and pharmacodynamics of progastrin-derived peptides

    DEFF Research Database (Denmark)

    Hansen, Carsten Palnaes

    2003-01-01

    The elimination of progastrin-derived peptides was a first-order process, also at supraphysiological concentrations in plasma. The site of extraction was dependent on the molecular size of the peptides and not on their bioactivity. Apart from the kidneys and brain, where the extraction...

  1. Antimicrobial and immunomodulatory activities of PR-39 derived peptides.

    Directory of Open Access Journals (Sweden)

    Edwin J A Veldhuizen

    Full Text Available The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics.

  2. Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides

    Science.gov (United States)

    Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

    2014-01-01

    The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

  3. Bioactive Properties of Maillard Reaction Products Generated From Food Protein-derived Peptides.

    Science.gov (United States)

    Arihara, K; Zhou, L; Ohata, M

    Food protein-derived peptides are promising food ingredients for developing functional foods, since various bioactive peptides are released from food proteins. The Maillard reaction, which plays an important role in most processed foods, generates various chemical components during processing. Although changes of amino acids or proteins and reduced sugars by the Maillard reaction have been studied extensively, such changes of peptides by the Maillard reaction are still not resolved enough. Since food protein-derived peptides are widely utilized in many processed foods, it deserves concern and research on the changes of peptides by the Maillard reaction in foods during processing or storage. This chapter initially overviewed food protein-derived bioactive peptides. Then, Maillard reaction products generated from peptides are discussed. We focused particularly on their bioactivities. © 2017 Elsevier Inc. All rights reserved.

  4. Synthesis and characterization of arylamine derivatives of rauwolscine as molecular probes for alpha 2-adrenergic receptors

    International Nuclear Information System (INIS)

    Lanier, S.M.; Graham, R.M.; Hess, H.J.; Grodski, A.; Repaske, M.G.; Nunnari, J.M.; Limbird, L.E.; Homcy, C.J.

    1987-01-01

    The selective alpha 2-adrenergic receptor antagonist rauwolscine was structurally modified to yield a series of arylamine carboxamide derivatives, which were investigated as potential molecular probes for the localization and structural characterization of alpha 2-adrenergic receptors. The arylamine carboxamides differ in the number of carbon atoms separating the reactive phenyl moiety from the fused ring structure of the parent compound, rauwolscine carboxylate. Competitive inhibition studies with [ 3 H]rauwolscine in rat kidney membranes indicate that the affinity for the carboxamide derivatives is inversely related to the length of the carbon spacer arm with rauwolscine 4-aminophenyl carboxamide exhibiting the highest affinity (Kd = 2.3 +/- 0.2 nM). Radioiodination of rau-AMPC yields a ligand, 125 I-rau-AMPC, which binds to rat kidney alpha 2-adrenergic receptors with high affinity, as determined by both kinetic analysis (Kd = k2/k1 = 0.016 min-1/2.1 X 10(7) M-1 min-1 = 0.76 nM) and equilibrium binding studies (Kd = 0.78 +/- 0.16 nM). 125 I-rau-AMPC was quantitatively converted to the photolabile arylazide derivative 17 alpha-hydroxy-20 alpha-yohimban-16 beta-(N-4-azido-3-[ 125 I]iodophenyl) carboxamide ( 125 I-rau-AZPC). In a partially purified receptor preparation from porcine brain, this compound photolabels a major (Mr = 62,000) peptide. The labeling of this peptide is inhibited by adrenergic agonists and antagonists with a rank order of potency consistent with an alpha 2-adrenergic receptor binding site. Both 125 I-rau-AMPC and the photolabile arylazide derivative, 125 I-rau-AZPC, should prove useful as molecular probes for the structural and biochemical characterization of alpha 2-adrenergic receptors

  5. Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides

    Science.gov (United States)

    van Dijk, Albert; van Eldik, Mandy; Veldhuizen, Edwin J. A.; Tjeerdsma-van Bokhoven, Hanne L. M.; de Zoete, Marcel R.; Bikker, Floris J.; Haagsman, Henk P.

    2016-01-01

    Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2)-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11) we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS). N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives. PMID:26848845

  6. Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides.

    Directory of Open Access Journals (Sweden)

    Albert van Dijk

    Full Text Available Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11 we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS. N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives.

  7. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

    Directory of Open Access Journals (Sweden)

    Barbara Noli

    Full Text Available VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA coupled with high-performance liquid (HPLC or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.

  8. Food-derived bioactive peptides on inflammation and oxidative stress.

    Science.gov (United States)

    Chakrabarti, Subhadeep; Jahandideh, Forough; Wu, Jianping

    2014-01-01

    Chronic diseases such as atherosclerosis and cancer are now the leading causes of morbidity and mortality worldwide. Inflammatory processes and oxidative stress underlie the pathogenesis of these pathological conditions. Bioactive peptides derived from food proteins have been evaluated for various beneficial effects, including anti-inflammatory and antioxidant properties. In this review, we summarize the roles of various food-derived bioactive peptides in inflammation and oxidative stress and discuss the potential benefits and limitations of using these compounds against the burden of chronic diseases.

  9. Using Gas-Phase Guest-Host Chemistry to Probe the Structures of b Ions of Peptides

    Science.gov (United States)

    Somogyi, Árpád; Harrison, Alex G.; Paizs, Béla

    2012-12-01

    Middle-sized b n ( n ≥ 5) fragments of protonated peptides undergo selective complex formation with ammonia under experimental conditions typically used to probe hydrogen-deuterium exchange in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Other usual peptide fragments like y, a, a*, etc., and small b n ( n ≤ 4) fragments do not form stable ammonia adducts. We propose that complex formation of b n ions with ammonia is characteristic to macrocyclic isomers of these fragments. Experiments on a protonated cyclic peptide and N-terminal acetylated peptides fully support this hypothesis; the protonated cyclic peptide does form ammonia adducts while linear b n ions of acetylated peptides do not undergo complexation. Density functional theory (DFT) calculations on the proton-bound dimers of all-Ala b 4 , b 5 , and b 7 ions and ammonia indicate that the ionizing proton initially located on the peptide fragment transfers to ammonia upon adduct formation. The ammonium ion is then solvated by N+-H…O H-bonds; this stabilization is much stronger for macrocyclic b n isomers due to the stable cage-like structure formed and entropy effects. The present study demonstrates that gas-phase guest-host chemistry can be used to selectively probe structural features (i.e., macrocyclic or linear) of fragments of protonated peptides. Stable ammonia adducts of b 9 , b 9 -A, and b 9 -2A of A8YA, and b 13 of A20YVFL are observed indicating that even these large b-type ions form macrocyclic structures.

  10. Dimerization effects on coacervation property of an elastin-derived synthetic peptide (FPGVG)5.

    Science.gov (United States)

    Suyama, Keitaro; Taniguchi, Suguru; Tatsubo, Daiki; Maeda, Iori; Nose, Takeru

    2016-04-01

    Elastin, a core protein of the elastic fibers, exhibits the coacervation (temperature-dependent reversible association/dissociation) under physiological conditions. Because of this characteristic, elastin and elastin-derived peptides have been considered to be useful as base materials for developing various biomedical products, skin substitutes, synthetic vascular grafts, and drug delivery systems. Although elastin-derived polypeptide (Val-Pro-Gly-Val-Gly)n also has been known to demonstrate coacervation property, a sufficiently high (VPGVG)n repetition number (n>40) is required for coacervation. In the present study, a series of elastin-derived peptide (Phe-Pro-Gly-Val-Gly)5 dimers possessing high coacervation potential were newly developed. These novel dimeric peptides exhibited coacervation at significantly lower concentrations and temperatures than the commonly used elastin-derived peptide analogs; this result suggests that the coacervation ability of the peptides is enhanced by dimerization. Circular dichroism (CD) measurements indicate that the dimers undergo similar temperature-dependent and reversible conformational changes when coacervation occurs. The molecular dynamics calculation results reveal that the sheet-turn-sheet motif involving a type II β-turn-like structure commonly observed among the dimers and caused formation of globular conformation of them. These synthesized peptide dimers may be useful not only as model peptides for structural analysis of elastin and elastin-derived peptides, but also as base materials for developing various temperature-sensitive biomedical and industrial products. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  11. Identification of MHC class I H-2 Kb/Db-restricted immunogenic peptides derived from retinal proteins

    DEFF Research Database (Denmark)

    Wang, Mingjun; Bai, Fang; Pries, Mette

    2006-01-01

    PURPOSE: To identify H-2 Kb/Db-binding immunogenic peptides derived from retinal proteins. METHODS: Computer-based prediction was used to identify potentially H-2 Kb/Db-binding peptides derived from the interphotoreceptor retinol-binding protein (IRBP), soluble retinal antigen (S...... on day 21 after immunization with IRBP or IRBP and the immunogenic peptides. RESULTS: All the 21 predicted peptides were found to upregulate expression of H-2 Kb/Db on RMA-S cells. Five peptides, the two IRBP-derived peptides IRBP89-96 and IRBP(101-108), and the three PEDF-derived peptides, PEDF389....... The immunogenic peptides alone did not induce inflammation in the eyes, but they could enhance severity of uveitis induced by IRBP. CONCLUSIONS: Five of 21 H-2 Kb/Db-binding retinal protein-derived peptides were found to be immunogenic, suggesting that these peptides could function as autoantigenic epitopes...

  12. 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.

  13. BioPepDB: an integrated data platform for food-derived bioactive peptides.

    Science.gov (United States)

    Li, Qilin; Zhang, Chao; Chen, Hongjun; Xue, Jitong; Guo, Xiaolei; Liang, Ming; Chen, Ming

    2018-03-12

    Food-derived bioactive peptides play critical roles in regulating most biological processes and have considerable biological, medical and industrial importance. However, a large number of active peptides data, including sequence, function, source, commercial product information, references and other information are poorly integrated. BioPepDB is a searchable database of food-derived bioactive peptides and their related articles, including more than four thousand bioactive peptide entries. Moreover, BioPepDB provides modules of prediction and hydrolysis-simulation for discovering novel peptides. It can serve as a reference database to investigate the function of different bioactive peptides. BioPepDB is available at http://bis.zju.edu.cn/biopepdbr/ . The web page utilises Apache, PHP5 and MySQL to provide the user interface for accessing the database and predict novel peptides. The database itself is operated on a specialised server.

  14. 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.

  15. 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

  16. Development of an oxygen-sensitive degradable peptide probe for the imaging of hypoxia-inducible factor-1-active regions in tumors.

    Science.gov (United States)

    Ueda, Masashi; Ogawa, Kei; Miyano, Azusa; Ono, Masahiro; Kizaka-Kondoh, Shinae; Saji, Hideo

    2013-12-01

    We aimed to develop a radiolabeled peptide probe for the imaging of hypoxia-inducible factor-1 (HIF-1)-active tumors. We synthesized the peptide probes that contain or lack an essential sequence of the oxygen-dependent degradation of HIF-1α in proteasomes ((123/125)I-DKOP30 or (125)I-mDKOP, respectively). The degradation of probes was evaluated in vitro using cell lysates containing proteasomes. In vivo biodistribution study, planar imaging, autoradiography, and comparison between probe accumulation and HIF-1 transcriptional activity were also performed. The (125)I-DKOP30 underwent degradation in a proteasome-dependent manner, while (125)I-mDKOP was not degraded. Biodistribution analysis showed (125)I-DKOP30 accumulation in tumors. The tumors were clearly visualized by in vivo imaging, and intratumoral distribution of (125)I-DKOP30 coincided with the HIF-1α-positive hypoxic regions. Tumoral accumulation of (125)I-DKOP30 was significantly correlated with HIF-1-dependent luciferase bioluminescence, while that of (125)I-mDKOP was not. (123)I-DKOP30 is a useful peptide probe for the imaging of HIF-1-active tumors.

  17. Marine-Derived Bioactive Peptides with Pharmacological Activities- A Review

    Directory of Open Access Journals (Sweden)

    Sana Rabiei

    2017-10-01

    Full Text Available Some nutritional factors are related to chronic disease. In response to increased concern regarding nutrition and health, the functional and nutraceuticals food markets have been developed. During food digestion, proteins are hydrolyzed and a wide range of peptides are formed. Some of these peptides have special structures which permit them to confer particular biological functions. Marine animals which involve more than half of the world biological varieties are a wide source of bioactive proteins and peptides. Marine derived peptides show various physiologic functions such as anti-oxidant, antimicrobial, anti-cancer, Angiotensin1-Converting Enzyme (ACE glucosidase and a-amylase inhibitory effects in vitro. Before application of marine bioactive peptides as nutraceuticals or functional food ingredients, their efficacy should be approved through pre-clinical animal and then clinical studies. The aim of this study was to review the studies conducted on the pharmacological effect of marine bioactive peptides in animal models and humans.

  18. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.

    Directory of Open Access Journals (Sweden)

    Xudong Qiu

    Full Text Available Peptide probes for imaging retinal ganglion cell (RGC apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in

  19. Milk derived bioactive peptides and their impact on human health – A review

    Directory of Open Access Journals (Sweden)

    D.P. Mohanty

    2016-09-01

    Full Text Available Milk-derived bioactive peptides have been identified as potential ingredients of health-promoting functional foods. These bioactive peptides are targeted at diet-related chronic diseases especially the non-communicable diseases viz., obesity, cardiovascular diseases and diabetes. Peptides derived from the milk of cow, goat, sheep, buffalo and camel exert multifunctional properties, including anti-microbial, immune modulatory, anti-oxidant, inhibitory effect on enzymes, anti-thrombotic, and antagonistic activities against various toxic agents. Majority of those regulate immunological, gastrointestinal, hormonal and neurological responses, thereby playing a vital role in the prevention of cancer, osteoporosis, hypertension and other disorders as discussed in this review. For the commercial production of such novel bioactive peptides large scale technologies based on membrane separation and ion exchange chromatography methods have been developed. Separation and identification of those peptides and their pharmacodynamic parameters are necessary to transfer their potent functional properties into food applications. The present review summarizes the preliminary classes of bioactive milk-derived peptides along with their physiological functions, general characteristics and potential applications in health-care.

  20. Novel haemoglobin-derived antimicrobial peptides from chicken (Gallus gallus) blood: purification, structural aspects and biological activity.

    Science.gov (United States)

    Vasilchenko, A S; Rogozhin, E A; Vasilchenko, A V; Kartashova, O L; Sycheva, M V

    2016-12-01

    To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents. © 2016 The Society for Applied Microbiology.

  1. Novel angiotensin-converting enzyme (ACE) inhibitory peptides derived from boneless chicken leg meat.

    Science.gov (United States)

    Terashima, Masaaki; Baba, Takako; Ikemoto, Narumi; Katayama, Midori; Morimoto, Tomoko; Matsumura, Saki

    2010-06-23

    Four peptides that inhibit angiotensin-converting enzyme (ACE) were separated from the hydorlysate of boneless chicken leg meat digested with artificial gastric juice (pepsin). Two peptides were identified as the peptides encrypted in myosin heavy chain. The peptide P1 (MNVKHWPWMK) corresponds to the amino acid sequence from amino acids 825 to 834 of myosin heavy chain, and the peptide P4 (VTVNPYKWLP) corresponds to the amino acid sequence from amino acids 125 to 135 of myosin heavy chain. They are novel ACE inhibitory peptides derived from chicken, and IC(50) values of P1 and P4 were determined as 228 and 5.5 microM, respectively. Although these values were much larger than 0.022 microM for captopril, a typical synthetic ACE inhibitor, they are comparable to IC(50) values reported for various ACE inhibitory peptides derived from foods. Because the peptide P4 has a relatively low IC(50) value, it is a good starting substance for designing food supplements for hypertensive patients.

  2. Immunogenicity of HLA Class I and II Double Restricted Influenza A-Derived Peptides

    DEFF Research Database (Denmark)

    Pedersen, Sara Ram; Christensen, Jan Pravsgaard; Buus, Søren

    2016-01-01

    The aim of the present study was to identify influenza A-derived peptides which bind to both HLA class I and -II molecules and by immunization lead to both HLA class I and class II restricted immune responses. Eight influenza A-derived 9-11mer peptides with simultaneous binding to both HLA-A*02...... four of the double binding peptides did result in HLA-A*02:01 restricted responses only. According to their cytokine profile, the CD4 T cell responses were of the Th2 type. In influenza infected mice, we were unable to detect natural processing in vivo of the double restricted peptides and in line...... with this, peptide vaccination did not decrease virus titres in the lungs of intranasally influenza challenged mice. Our data show that HLA class I and class II double binding peptides can be identified by bioinformatics and biochemical technology. By immunization, double binding peptides can give rise...

  3. 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.

  4. Antimicrobial activity of bovine NK-lysin-derived peptides on Mycoplasma bovis

    Science.gov (United States)

    Antimicrobial peptides (AMPs) are a diverse group of molecules which play an important role in the innate immune response. Bovine NK-lysins, a type of AMP, have been predominantly found in the granules of cytotoxic T-lymphocytes and NK-cells. Bovine NK-lysin-derived peptides demonstrate antimicrobia...

  5. Lactoferrin-derived Peptides Active towards Influenza: Identification of Three Potent Tetrapeptide Inhibitors.

    Science.gov (United States)

    Scala, Maria Carmina; Sala, Marina; Pietrantoni, Agostina; Spensiero, Antonia; Di Micco, Simone; Agamennone, Mariangela; Bertamino, Alessia; Novellino, Ettore; Bifulco, Giuseppe; Gomez-Monterrey, Isabel M; Superti, Fabiana; Campiglia, Pietro

    2017-09-06

    Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.

  6. Formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations - A review.

    Science.gov (United States)

    Zhao, Cindy J; Schieber, Andreas; Gänzle, Michael G

    2016-11-01

    Fermented foods are valued for their rich and complex odour and taste. The metabolic activity of food-fermenting microorganisms determines food quality and generates odour and taste compounds. This communication reviews the formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations. Pathways of the generation of taste compounds are presented for soy sauce, cheese, fermented meats, and bread. Proteolysis or autolysis during food fermentations generates taste-active amino acids and peptides; peptides derived from proteolysis particularly impart umami taste (e.g. α-glutamyl peptides) or bitter taste (e.g. hydrophobic peptides containing proline). Taste active peptide derivatives include pyroglutamyl peptides, γ-glutamyl peptides, and succinyl- or lactoyl amino acids. The influence of fermentation microbiota on proteolysis, and peptide hydrolysis, and the metabolism of glutamate and arginine is well understood, however, the understanding of microbial metabolic activities related to the formation of taste-active peptide derivatives is incomplete. Improved knowledge of the interactions between taste-active compounds will enable the development of novel fermentation strategies to develop tastier, less bitter, and low-salt food products, and may provide novel and "clean label" ingredients to improve the taste of other food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Interaction of MreB-derived antimicrobial peptides with membranes.

    Science.gov (United States)

    Saikia, Karabi; Chaudhary, Nitin

    2018-03-25

    Antimicrobial peptides are critical components of defense systems in living forms. The activity is conferred largely by the selective membrane-permeabilizing ability. In our earlier work, we derived potent antimicrobial peptides from the 9-residue long, N-terminal amphipathic helix of E. coli MreB protein. The peptides display broad-spectrum activity, killing not only Gram-positive and Gram-negative bacteria but opportunistic fungus, Candida albicans as well. These results proved that membrane-binding stretches of bacterial proteins could turn out to be self-harming when applied from outside. Here, we studied the membrane-binding and membrane-perturbing potential of these peptides. Steady-state tryptophan fluorescence studies with tryptophan extended peptides, WMreB 1-9 and its N-terminal acetylated analog, Ac-WMreB 1-9 show preferential binding to negatively-charged liposomes. Both the peptides cause permeabilization of E. coli inner and outer-membranes. Tryptophan-lacking peptides, though permeabilize the outer-membrane efficiently, little permeabilization of the inner-membrane is observed. These data attest membrane-destabilization as the mechanism of rapid bacterial killing. This study is expected to motivate the research in identifying microbes' self-sequences to combat them. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Development and clinical applications of a small peptide as a radiolabeled in vivo diagnostic probe

    International Nuclear Information System (INIS)

    Reubi, J.C.; Lamberts, S.W.; Krenning, E.

    1995-01-01

    Several dozens of small peptides, widely distributed in the human body, highly potent and important regulators of biological processes in numerous tissues, have been identified in the past several years. One of those, somatostatin, the first of such peptides used in the nuclear medicine field, has been developed as an in vivo labeled diagnostic probe for a variety of pathologies. Basic knowledge on somatostatin, somatostatin receptors and somatostatin target tissues as well as on the clinical implications of this diagnostic tool are briefly reviewed. (authors). 9 refs., 3 figs

  9. Electrochemical detection of human papillomavirus DNA type 16 using a pyrrolidinyl peptide nucleic acid probe immobilized on screen-printed carbon electrodes.

    Science.gov (United States)

    Jampasa, Sakda; Wonsawat, Wanida; Rodthongkum, Nadnudda; Siangproh, Weena; Yanatatsaneejit, Pattamawadee; Vilaivan, Tirayut; Chailapakul, Orawon

    2014-04-15

    An electrochemical biosensor based on an immobilized anthraquinone-labeled pyrrolidinyl peptide nucleic acid (acpcPNA) probe was successfully developed for the selective detection of human papillomavirus (HPV) type 16 DNA. A 14-mer acpcPNA capture probe was designed to recognize a specific 14 nucleotide region of HPV type 16 L1 gene. The redox-active label anthraquinone (AQ) was covalently attached to the N-terminus of the acpcPNA probe through an amide bond. The probe was immobilized onto a chitosan-modified disposable screen-printed carbon electrode via a C-terminal lysine residue using glutaraldehyde as a cross-linking agent. Hybridization with the target DNA was studied by measuring the electrochemical signal response of the AQ label using square-wave voltammetric analysis. The calibration curve exhibited a linear range between 0.02 and 12.0 µM with a limit of detection and limit of quantitation of 4 and 14 nM, respectively. This DNA sensing platform was successfully applied to detect the HPV type 16 DNA from a PCR amplified (240 bp fragment of the L1 gene) sample derived from the HPV type 16 positive human cancer cell line (SiHa), and failed to detect the HPV-negative c33a cell line. The sensor probe exhibited very high selectivity for the complementary 14 base oligonucleotide over the non-complementary oligonucleotides with sequences derived from HPV types 18, 31 and 33. The proposed sensor provides an inexpensive tool for the early stage detection of HPV type 16, which is an important biomarker for cervical cancer. © 2013 Elsevier B.V. All rights reserved.

  10. Peptide Probes Reveal a Hydrophobic Steric Ratchet in the Anthrax Toxin Protective Antigen Translocase.

    Science.gov (United States)

    Colby, Jennifer M; Krantz, Bryan A

    2015-11-06

    Anthrax toxin is a tripartite virulence factor produced by Bacillus anthracis during infection. Under acidic endosomal pH conditions, the toxin's protective antigen (PA) component forms a transmembrane channel in host cells. The PA channel then translocates its two enzyme components, lethal factor and edema factor, into the host cytosol under the proton motive force. Protein translocation under a proton motive force is catalyzed by a series of nonspecific polypeptide binding sites, called clamps. A 10-residue guest/host peptide model system, KKKKKXXSXX, was used to functionally probe polypeptide-clamp interactions within wild-type PA channels. The guest residues were Thr, Ala, Leu, Phe, Tyr, and Trp. In steady-state translocation experiments, the channel blocked most tightly with peptides that had increasing amounts of nonpolar surface area. Cooperative peptide binding was observed in the Trp-containing peptide sequence but not the other tested sequences. Trp substitutions into a flexible, uncharged linker between the lethal factor amino-terminal domain and diphtheria toxin A chain expedited translocation. Therefore, peptide-clamp sites in translocase channels can sense large steric features (like tryptophan) in peptides, and while these steric interactions may make a peptide translocate poorly, in the context of folded domains, they can make the protein translocate more rapidly presumably via a hydrophobic steric ratchet mechanism. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Design of a dual-function peptide probe as a binder of angiotensin II and an inducer of silver nanoparticle aggregation for use in label-free colorimetric assays.

    Science.gov (United States)

    Okochi, Mina; Kuboyama, Masashi; Tanaka, Masayoshi; Honda, Hiroyuki

    2015-09-01

    Label-free colorimetric assays using metallic nanoparticles have received much recent attention, for their application in simple and sensitive methods for detection of biomolecules. Short peptide probes that can bind to analyte biomolecules are attractive ligands in molecular nanotechnology; however, identification of biological recognition motifs is usually based on trial-and-error experiments. Herein, a peptide probe was screened for colorimetric detection of angiotensin II (Ang II) using a mechanism for non-crosslinking aggregation of silver nanoparticles (AgNPs). The dual-function peptides, which bind to the analyte and induce AgNP aggregation, were identified using a two-step strategy: (1) screening of an Ang II-binding peptide from an Ang II receptor sequence library, using SPOT technology, which enable peptides synthesis on cellulose membranes via an Fmoc method and (2) selection of peptide probes that effectively induce aggregation of AgNPs using a photolinker modified peptide array. Using the identified peptide probe, KGKNKRRR, aggregation of AgNPs was detected by observation of a pink color in the absence of Ang II, whereas AgNPs remained dispersed in the presence of Ang II (yellow). The color changes were not observed in the presence of other hormone molecules. Ang II could be detected within 15 min, with a detection limit of 10 µM, by measuring the ratio of absorbance at 400 nm and 568 nm; the signal could also be observed with the naked eye. These data suggest that the peptide identified here could be used as a probe for simple and rapid colorimetric detection of Ang II. This strategy for the identification of functional peptides shows promise for the development of colorimetric detection of various diagnostically important biomolecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Antimicrobial Effects of Helix D-derived Peptides of Human Antithrombin III*

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K. V.; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

    2014-01-01

    Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix d-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. PMID:25202017

  13. Competition between bound and free peptides in an ELISA-based procedure that assays peptides derived from protein digests

    Directory of Open Access Journals (Sweden)

    Pace Umberto

    2006-05-01

    Full Text Available Abstract Background We describe an ELISA-based method that can be used to identify and quantitate proteins in biological samples. In this method, peptides in solution, derived from proteolytic digests of the sample, compete with substrate-attached synthetic peptides for antibodies, also in solution, generated against the chosen peptides. The peptides used for the ELISA are chosen on the basis of their being (i products of the proteolytic (e.g. tryptic digestion of the protein to be identified and (ii unique to the target protein, as far as one can know from the published sequences. Results In this paper we describe the competition assay and we define the optimal conditions for the most effective assay. We have performed an analysis of the kinetics of interaction between the four components of the assay: the plastic substratum to which the peptide is bound, the bound peptide itself, the competing added peptide, and the antibody that is specific for the peptide and we compare the results of theoretical simulations to the actual data in some model systems. Conclusion The data suggest that the peptides bind to the plastic substratum in more than one conformation and that, once bound, the peptide displays different affinities for the antibody, depending on how it has bound to the plate

  14. Antimicrobial effects of helix D-derived peptides of human antithrombin III.

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K V; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

    2014-10-24

    Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix D-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Human lactoferricin derived di-peptides deploying loop structures induce apoptosis specifically in cancer cells through targeting membranous phosphatidylserine.

    Science.gov (United States)

    Riedl, Sabrina; Leber, Regina; Rinner, Beate; Schaider, Helmut; Lohner, Karl; Zweytick, Dagmar

    2015-11-01

    Host defense-derived peptides have emerged as a novel strategy for the development of alternative anticancer therapies. In this study we report on characteristic features of human lactoferricin (hLFcin) derivatives which facilitate specific killing of cancer cells of melanoma, glioblastoma and rhabdomyosarcoma compared with non-specific derivatives and the synthetic peptide RW-AH. Changes in amino acid sequence of hLFcin providing 9-11 amino acids stretched derivatives LF11-316, -318 and -322 only yielded low antitumor activity. However, the addition of the repeat (di-peptide) and the retro-repeat (di-retro-peptide) sequences highly improved cancer cell toxicity up to 100% at 20 μM peptide concentration. Compared to the complete parent sequence hLFcin the derivatives showed toxicity on the melanoma cell line A375 increased by 10-fold and on the glioblastoma cell line U-87mg by 2-3-fold. Reduced killing velocity, apoptotic blebbing, activation of caspase 3/7 and formation of apoptotic DNA fragments proved that the active and cancer selective peptides, e.g. R-DIM-P-LF11-322, trigger apoptosis, whereas highly active, though non-selective peptides, such as DIM-LF11-318 and RW-AH seem to kill rapidly via necrosis inducing membrane lyses. Structural studies revealed specific toxicity on cancer cells by peptide derivatives with loop structures, whereas non-specific peptides comprised α-helical structures without loop. Model studies with the cancer membrane mimic phosphatidylserine (PS) gave strong evidence that PS only exposed by cancer cells is an important target for specific hLFcin derivatives. Other negatively charged membrane exposed molecules as sialic acid, heparan and chondroitin sulfate were shown to have minor impact on peptide activity. Copyright © 2015. Published by Elsevier B.V.

  16. NONINVASIVE OPTICAL IMAGING OF STAPHYLOCOCCUS AUREUS INFECTION IN VIVO USING AN ANTIMICROBIAL PEPTIDE FRAGMENT BASED NEAR-INFRARED FLUORESCENT PROBES

    Directory of Open Access Journals (Sweden)

    CUICUI LIU

    2013-07-01

    Full Text Available The diagnosis of bacterial infections remains a major challenge in medicine. Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as light-emitting enzymes or fluorescent proteins. However, there are many circumstances where genetic reporters are not applicable, and there is an urgent need for exogenous synthetic probes that can selectively target bacteria. Optical imaging of bacteria in vivo is much less developed than methods such as radioimaging and MRI. Furthermore near-infrared (NIR dyes with emission wavelengths in the region of 650–900 nm can propagate through two or more centimeters of tissue and may enable deeper tissue imaging if sensitive detection techniques are employed. Here we constructed an antimicrobial peptide fragment UBI29-41-based near-infrared fluorescent imaging probe. The probe is composed of UBI29-41 conjugated to a near infrared dye ICG-Der-02. UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells. The probe allows detection of Staphylococcus aureus infection (5 × 107 cells in a mouse local infection model using whole animal near-infrared fluorescence imaging. Furthermore, we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria. The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.

  17. Transferrin-derived synthetic peptide induces highly conserved pro-inflammatory responses of macrophages.

    Science.gov (United States)

    Haddad, George; Belosevic, Miodrag

    2009-02-01

    We examined the induction of macrophage pro-inflammatory responses by transferrin-derived synthetic peptide originally identified following digestion of transferrin from different species (murine, bovine, human N-lobe and goldfish) using elastase. The mass spectrometry analysis of elastase-digested murine transferrin identified a 31 amino acid peptide located in the N2 sub-domain of the transferrin N-lobe, that we named TMAP. TMAP was synthetically produced and shown to induce a number of pro-inflammatory genes by quantitative PCR. TMAP induced chemotaxis, a potent nitric oxide response, and TNF-alpha secretion in different macrophage populations; P338D1 macrophage-like cells, mouse peritoneal macrophages, mouse bone marrow-derived macrophages (BMDM) and goldfish macrophages. The treatment of BMDM cultures with TMAP stimulated the production of nine cytokines and chemokines (IL-6, MCP-5, MIP-1 alpha, MIP-1 gamma, MIP-2, GCSF, KC, VEGF, and RANTES) that was measured using cytokine antibody array and confirmed by Western blot. Our results indicate that transferrin-derived peptide, TMAP, is an immunomodulating molecule capable of inducing pro-inflammatory responses in lower and higher vertebrates.

  18. Characterization of trypsin-derived peptides acrylamide-adducted hemoglobin

    International Nuclear Information System (INIS)

    Springer, D.L.; Goheen, S.C.; Edmonds, C.G.; McCulloch, M.; Sylvester, D.M.; Sander, C.; Bull, R.J.

    1991-01-01

    Even though there are a number of sources for human exposure to acrylamide, reliable biomarkers of exposure are not available. In an effort to develop such a biomarker, the authors are characterizing peptides derived from trypsin digests of acrylamide-adducted hemoglobin. For this, radiolabeled acrylamide was incubated with this, radiolabeled acrylamide was incubated with purified human hemoglobin (Ao) and decomposition products removed by dialysis. When the adducted hemoglobin was separated by reverse-phase HPLC, radioactivity eluted with the α and β subunits, suggesting covalent binding. Digestion of individual subunits with trypsin followed by reverse phase HPLC, indicated that most of the radioactivity associated with the α subunit co-eluted with a single peptide. Similar results were observed for the β subunit except that significant amounts of radioactivity eluted with the solvent front, suggesting that radioactivity was released by trypsin digestion. Currently, these preparation are under further characterization by electrospray ionization mass spectrometry. This approach will aid in the identification of the adducted will aid in the identification of the adducted peptide and subsequent preparation of an acrylamide-specific antibody

  19. Laminin-111-derived peptide conjugated fibrin hydrogel restores salivary gland function.

    Directory of Open Access Journals (Sweden)

    Kihoon Nam

    Full Text Available Hyposalivation reduces the patient quality of life, as saliva is important for maintaining oral health. Current treatments for hyposalivation are limited to medications such as the muscarinic receptor agonists, pilocarpine and cevimeline. However, these therapies only provide temporary relief. Therefore, alternative therapies are essential to restore salivary gland function. An option is to use bioengineered scaffolds to promote functional salivary gland regeneration. Previous studies demonstrated that the laminin-111 protein is critical for intact salivary gland cell cluster formation and organization. However, laminin-111 protein as a whole is not suitable for clinical applications as some protein domains may contribute to unwanted side effects such as degradation, tumorigenesis and immune responses. Conversely, the use of synthetic laminin-111 peptides makes it possible to minimize the immune reactivity or pathogen transfer. In addition, it is relatively simple and inexpensive as compared to animal-derived proteins. Therefore, the goal of this study was to demonstrate whether a 20 day treatment with laminin-111-derived peptide conjugated fibrin hydrogel promotes tissue regeneration in submandibular glands of a wound healing mouse model. In this study, laminin-111-derived peptide conjugated fibrin hydrogel significantly accelerated formation of salivary gland tissue. The regenerated gland tissues displayed not only structural but also functional restoration.

  20. Antimicrobial activity of the indolicidin-derived novel synthetic peptide In-58.

    Science.gov (United States)

    Vasilchenko, A S; Vasilchenko, A V; Pashkova, T M; Smirnova, M P; Kolodkin, N I; Manukhov, I V; Zavilgelsky, G B; Sizova, E A; Kartashova, O L; Simbirtsev, A S; Rogozhin, E A; Duskaev, G K; Sycheva, M V

    2017-12-01

    Natural peptides with antimicrobial activity are extremely diverse, and peptide synthesis technologies make it possible to significantly improve their properties for specific tasks. Here, we investigate the biological properties of the natural peptide indolicidin and the indolicidin-derived novel synthetic peptide In-58. In-58 was generated by replacing all tryptophan residues on phenylalanine in D-configuration; the α-amino group in the main chain also was modified by unsaturated fatty acid. Compared with indolicidin, In-58 is more bactericidal, more resistant to proteinase K, and less toxic to mammalian cells. Using molecular physics approaches, we characterized the action of In-58 on bacterial cells at the cellular level. Also, we have found that studied peptides damage bacterial membranes. Using the Escherichia coli luminescent biosensor strain MG1655 (pcolD'::lux), we investigated the action of indolicidin and In-58 at the subcellular level. At subinhibitory concentrations, indolicidin and In-58 induced an SOS response. Our data suggest that indolicidin damages the DNA, but bacterial membrane perturbation is its principal mode of action. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  1. Lumazine Peptides from the Marine-Derived Fungus Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    Minjung You

    2015-03-01

    Full Text Available Terrelumamides A (1 and B (2, two new lumazine-containing peptides, were isolated from the culture broth of the marine-derived fungus Aspergillus terreus. From the results of combined spectroscopic and chemical analyses, the structures of these compounds were determined to be linear assemblies of 1-methyllumazine-6-carboxylic acid, an amino acid residue and anthranilic acid methyl ester connected by peptide bonds. These new compounds exhibited pharmacological activity by improving insulin sensitivity, which was evaluated in an adipogenesis model using human bone marrow mesenchymal stem cells. In addition, the compounds exhibited fluorescence changes upon binding to DNA, demonstrating their potential applications to DNA sequence recognition.

  2. Hemopressins and other hemoglobin-derived peptides in mouse brain: Comparison between brain, blood, and heart peptidome and regulation in Cpefat/fat mice

    Science.gov (United States)

    Gelman, Julia S.; Sironi, Juan; Castro, Leandro M.; Ferro, Emer S.; Fricker, Lloyd D.

    2010-01-01

    Many hemoglobin-derived peptides are present in mouse brain, and several of these have bioactive properties including the hemopressins, a related series of peptides that bind to cannabinoid CB1 receptors. Although hemoglobin is a major component of red blood cells, it is also present in neurons and glia. To examine whether the hemoglobin-derived peptides in brain are similar to those present in blood and heart, we used a peptidomics approach involving mass spectrometry. Many hemoglobin-derived peptides are found only in brain and not in blood, whereas all hemoglobin-derived peptides found in heart were also seen in blood. Thus, it is likely that the majority of the hemoglobin-derived peptides detected in brain are produced from brain hemoglobin and not erythrocytes. We also examined if the hemopressins and other major hemoglobin-derived peptides were regulated in the Cpefat/fat mouse; previously these mice were reported to have elevated levels of several hemoglobin-derived peptides. Many, but not all of the hemoglobin-derived peptides were elevated in several brain regions of the Cpefat/fat mouse. Taken together, these findings suggest that the post-translational processing of alpha and beta hemoglobin into the hemopressins, as well as other peptides, is upregulated in some but not all Cpefat/fat mouse brain regions. PMID:20202081

  3. PreproVIP-derived peptides in the human female genital tract: expression and biological function

    DEFF Research Database (Denmark)

    Bredkjoer, H E; Palle, C; Ekblad, E

    1997-01-01

    The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination with immunohistoc......The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination...... with immunohistochemistry were used. The effect of preproVIP 22-79, preproVIP 111-122 and preproVIP 156-170 on genital smooth muscle activity in the Fallopian tube was investigated in vitro and compared to that of VIP. All the preproVIP-derived peptides were expressed throughout the genital tract in neuronal elements...

  4. Specificity of B-type natriuretic peptide assays

    DEFF Research Database (Denmark)

    Saenger, Amy K.; Rodriguez-Fraga, Olaia; Ler, Ranka

    2017-01-01

    BACKGROUND: B-type natriuretic peptides (BNPs) are used clinically to diagnose and monitor heart failure and are present in the circulation as multiple proBNP-derived fragments. We investigated the specificity of BNP immunoassays with glycosylated and nonglycosylated BNP, N-terminal proBNP (NT......-proBNP), and proBNP peptides to probe the cross-reactivity of each assay. METHODS: Nine B-type natriuretic peptides were studied, including synthetic and recombinant BNP (Shionogi, Scios, Mayo), human and synthetic glycosylated and nonglycosylated NT-proBNP (HyTest, Roche Diagnostics), and human glycosylated......-Rad, Goetze] were evaluated. Specificity was assessed by calculating the recovery between baseline and peptide-spiked human plasma pools at target concentrations of 100 ng/L BNP, 300 ng/L proBNP, or 450 ng/L NT-proBNP. All assays were performed in duplicate. RESULTS: BNP and NT-proBNP assays demonstrated...

  5. Dissecting the Structure-Function Relationship of a Fungicidal Peptide Derived from the Constant Region of Human Immunoglobulins

    OpenAIRE

    Ciociola, Tecla; Pertinhez, Thelma A.; Giovati, Laura; Sperindè, Martina; Magliani, Walter; Ferrari, Elena; Gatti, Rita; D'Adda, Tiziana; Spisni, Alberto; Conti, Stefania; Polonelli, Luciano

    2016-01-01

    Synthetic peptides encompassing sequences related to the complementarity-determining regions of antibodies or derived from their constant region (Fc peptides) were proven to exert differential antimicrobial, antiviral, antitumor, and/or immunomodulatory activities in vitro and/or in vivo, regardless of the specificity and isotype of the parental antibody. Alanine substitution derivatives of these peptides exhibited unaltered, increased, or decreased candidacidal activities in vitro. The bioac...

  6. Anti-Hemagglutinin Antibody Derived Lead Peptides for Inhibitors of Influenza Virus Binding.

    Directory of Open Access Journals (Sweden)

    Henry Memczak

    Full Text Available Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/Mute Swan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing.

  7. Alpha-amidated peptides derived from pro-opiomelanocortin in human pituitary tumours

    DEFF Research Database (Denmark)

    Fenger, M; Johnsen, A H

    1988-01-01

    Human pituitary tumours, obtained at surgery for Cushing's disease and Nelson's syndrome, were extracted and the content and molecular forms of pro-opiomelanocortin (POMC)-derived peptides determined by radioimmunoassay, gel chromatography, reversed-phase high-performance liquid chromatography....... In conclusion, all the molecular forms of the amidated peptides detected in tumours from patients with Cushing's disease and Nelson's syndrome were similar to the molecular forms found in the normal human pituitary. The main difference between the tumours and the normal pituitary was the greater amount...... (HPLC) and sequence analysis. In the tumours from patients with Cushing's disease the mean concentrations of amidated peptides relative to the total amount of POMC were as follows: alpha-MSH, 1.7%; amidated gamma-MSH (gamma 1-MSH), 8.5% and the peptide linking gamma-MSH and ACTH in the precursor (hinge...

  8. Site-selective modification of peptides: From "customizable units" to novel α-aryl and α-alkyl glycine derivatives, and components of branched peptides.

    Science.gov (United States)

    Romero-Estudillo, Iván; Saavedra, Carlos; Boto, Alicia; Álvarez, Eleuterio

    2015-09-01

    The creation of peptide libraries by site-selective modification of a few peptide substrates would increase the efficiency of discovery processes, but still is a real synthetic challenge. The site-selective modification of small peptides at serine or threonine residues, by using a short scission-addition procedure, allows the preparation of peptides with unnatural α-aryl glycines. In a similar way, the scission of hydroxyproline residues is the key step in the production of optically pure α-alkyl glycines which are precursors or components of branched peptides. With these versatile processes, a single peptide can be transformed into a variety of peptide derivatives. The process takes place under mild conditions, and good global yields are obtained. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 650-662, 2015. © 2015 Wiley Periodicals, Inc.

  9. MHC class II-derived peptides can bind to class II molecules, including self molecules, and prevent antigen presentation

    DEFF Research Database (Denmark)

    Rosloniec, E F; Vitez, L J; Buus, S

    1990-01-01

    the alpha k-3 peptide binds slightly less well. These combined data, suggesting that class II-derived peptides can bind to MHC class II molecules, including the autologous molecule from which they are derived, have important implications for the molecular basis of alloreactivity and autoreactivity. Further...... found in the first and third polymorphic regions (PMR) of the A alpha k chain (alpha k-1 and alpha k-3) were capable of inhibiting the presentation of three different HEL-derived peptide antigens to their appropriate T cells. In addition, the alpha k-1 peptide inhibited the presentation of the OVA(323......-339) immunodominant peptide to the I-Ad-restricted T cell hybridomas specific for it. Prepulsing experiments demonstrated that the PMR peptides were interacting with the APC and not with the T cell hybridomas. These observations were confirmed and extended by the demonstration that the alpha k-1 and alpha k-3...

  10. Efficient generation of dopamine neuron-like cells from skin-derived precursors with a synthetic peptide derived from von Hippel-Lindau protein.

    Science.gov (United States)

    Kubo, Atsuhiko; Yoshida, Tetsuhiko; Kobayashi, Nahoko; Yokoyama, Takaakira; Mimura, Toshiro; Nishiguchi, Takao; Higashida, Tetsuhiro; Yamamoto, Isao; Kanno, Hiroshi

    2009-12-01

    Skin-derived precursors (SKPs) from mammalian dermis represent neural crest-related stem cells capable of differentiating into both neural and mesodermal progency. SKPs are of clinical interest because they serve as accessible autologous donor cells for neuronal repair for neuronal intractable diseases. However, little is known about the efficient generation of neurons from SKPs, and phenotypes of neurons generated from SKPs have been restricted. In addition, the neuronal repair using their generated neurons as donor cells has not been achieved. The von Hippel-Lindau protein (pVHL) is one of the proteins that play an important role during neuronal differentiation, and recently neuronal differentiation of neural progenitor cells by intracellular delivery of a synthetic VHL peptide derived from elongin BC-binding site has been demonstrated. In the present study, a synthetic VHL peptide derived from elongin BC-binding site was conjugated to the protein transduction domain (PTD) of HIV-TAT protein (TATVHL peptide) to facilitate entry into cells, and we demonstrate the efficient generation of cells with dopaminergic phenotype from SKPs with the intracellular delivery of TATVHL peptide, and characterized the generated cells. The TATVHL peptide-treated SKPs expressed neuronal marker proteins, particularly dopamine neuron markers, and also up-regulated mRNA levels of proneural basic helix-loop-helix factors. After the TATVHL peptide treatment, transplanted SKPs into Parkinson's disease (PD) model rats sufficiently differentiated into dopamine neuron-like cells in PD model rats, and partially but significantly corrected behavior of PD model rats. The generated dopamine neuron-like cells are expected to serve as donor cells for neuronal repair for PD.

  11. Conformation of an Shc-derived phosphotyrosine-containing peptide complexed with the Grb2 SH2 domain

    International Nuclear Information System (INIS)

    Ogura, Kenji; Tsuchiya, Shigeo; Terasawa, Hiroaki; Yuzawa, Satoru; Hatanaka, Hideki; Mandiyan, Valsan; Schlessinger, Joseph; Inagaki, Fuyuhiko

    1997-01-01

    We have determined the structure of an Shc-derived phosphotyrosine-containing peptide complexed with Grb2 SH2 based on intra-and intermolecular NOE correlations observed by a series of isotope-filtered NMR experiments using a PFG z-filter. In contrast to an extended conformation of phosphotyrosine-containing peptides bound to Src, Syp and PLC γ SH2s, the Shc-derived peptide formed a turn at the +1 and +2 positions next to the phosphotyrosine residue. Trp 121 , located at the EF1 site of Grb2 SH2, blocked the peptide binding in an extended conformation. The present study confirms that each phosphotyrosine-containing peptide binds to the cognate SH2 with a specific conformation, which gives the structural basis for the binding specificity between SH2s and target proteins

  12. The remarkable stability of chimeric, sialic acid-derived alpha/delta-peptides in human blood plasma.

    Science.gov (United States)

    Saludes, Jonel P; Natarajan, Arutselvan; DeNardo, Sally J; Gervay-Hague, Jacquelyn

    2010-05-01

    Peptides are labile toward proteolytic enzymes, and structural modifications are often required to prolong their metabolic half-life and increase resistance. One modification is the incorporation of non-alpha-amino acids into the peptide to deter recognition by hydrolytic enzymes. We previously reported the synthesis of chimeric alpha/delta-peptides from glutamic acids (Glu) and the sialic acid derivative Neu2en. Conformational analyses revealed these constructs adopt secondary structures in water and may serve as conformational surrogates of polysialic acid. Polysialic acid is a tumor-associated polysaccharide and is correlated with cancer metastasis. Soluble polysialic acid is rapidly cleared from the blood limiting its potential for vaccine development. One motivation in developing structural surrogates of polysialic acid was to create constructs with increased bioavailability. Here, we report plasma stability profiles of Glu/Neu2en alpha/delta-peptides. DOTA was conjugated at the peptide N-termini by solid phase peptide synthesis, radiolabeled with (111)In, incubated in human blood plasma at 37 degrees C, and their degradation patterns monitored by cellulose acetate electrophoresis and radioactivity counting. Results indicate that these peptides exhibit a long half-life that is two- to three-orders of magnitude higher than natural alpha-peptides. These findings provide a viable platform for the synthesis of plasma stable, sialic acid-derived peptides that may find pharmaceutical application.

  13. Label-Free Potentiometry for Detecting DNA Hybridization Using Peptide Nucleic Acid and DNA Probes

    Science.gov (United States)

    Goda, Tatsuro; Singi, Ankit Balram; Maeda, Yasuhiro; Matsumoto, Akira; Torimura, Masaki; Aoki, Hiroshi; Miyahara, Yuji

    2013-01-01

    Peptide nucleic acid (PNA) has outstanding affinity over DNA for complementary nucleic acid sequences by forming a PNA-DNA heterodimer upon hybridization via Watson-Crick base-pairing. To verify whether PNA probes on an electrode surface enhance sensitivity for potentiometric DNA detection or not, we conducted a comparative study on the hybridization of PNA and DNA probes on the surface of a 10-channel gold electrodes microarray. Changes in the charge density as a result of hybridization at the solution/electrode interface on the self-assembled monolayer (SAM)-formed microelectrodes were directly transformed into potentiometric signals using a high input impedance electrometer. The charge readout allows label-free, reagent-less, and multi-parallel detection of target oligonucleotides without any optical assistance. The differences in the probe lengths between 15- to 22-mer dramatically influenced on the sensitivity of the PNA and DNA sensors. Molecular type of the capturing probe did not affect the degree of potential shift. Theoretical model for charged rod-like duplex using the Gouy-Chapman equation indicates the dominant effect of electrostatic attractive forces between anionic DNA and underlying electrode at the electrolyte/electrode interface in the potentiometry. PMID:23435052

  14. Label-Free Potentiometry for Detecting DNA Hybridization Using Peptide Nucleic Acid and DNA Probes

    Directory of Open Access Journals (Sweden)

    Yuji Miyahara

    2013-02-01

    Full Text Available Peptide nucleic acid (PNA has outstanding affinity over DNA for complementary nucleic acid sequences by forming a PNA-DNA heterodimer upon hybridization via Watson-Crick base-pairing. To verify whether PNA probes on an electrode surface enhance sensitivity for potentiometric DNA detection or not, we conducted a comparative study on the hybridization of PNA and DNA probes on the surface of a 10-channel gold electrodes microarray. Changes in the charge density as a result of hybridization at the solution/electrode interface on the self-assembled monolayer (SAM-formed microelectrodes were directly transformed into potentiometric signals using a high input impedance electrometer. The charge readout allows label-free, reagent-less, and multi-parallel detection of target oligonucleotides without any optical assistance. The differences in the probe lengths between 15- to 22-mer dramatically influenced on the sensitivity of the PNA and DNA sensors. Molecular type of the capturing probe did not affect the degree of potential shift. Theoretical model for charged rod-like duplex using the Gouy-Chapman equation indicates the dominant effect of electrostatic attractive forces between anionic DNA and underlying electrode at the electrolyte/electrode interface in the potentiometry.

  15. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    Directory of Open Access Journals (Sweden)

    Lei Zhu, Ning Guo, Quanzheng Li, Ying Ma, Orit Jacboson, Seulki Lee, Hak Soo Choi, James R. Mansfield, Gang Niu, Xiaoyuan Chen

    2012-01-01

    Full Text Available Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide.Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data.Results: The dual-labeled probe 64Cu-RGD-C(DOTA-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp derived from dynamic optical imaging (1.762 ± 0.020 is comparable to that from dynamic PET (1.752 ± 0.026.Conclusion: The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  16. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe.

    Science.gov (United States)

    Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/(64)Cu dual-labeled cyclic RGD peptide. The integrin α(v)β(3) binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD) method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data. The dual-labeled probe (64)Cu-RGD-C(DOTA)-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp) derived from dynamic optical imaging (1.762 ± 0.020) is comparable to that from dynamic PET (1.752 ± 0.026). The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  17. I-Ad-binding peptides derived from unrelated protein antigens share a common structural motif

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S

    1988-01-01

    on the I-Ad binding of the immunogenic peptide OVA 323-339. The results obtained demonstrated the very permissive nature of Ag-Ia interaction. We also showed that unrelated peptides that are good I-Ad binders share a common structural motif and speculated that recognition of such motifs could represent...... that I-Ad molecules recognize a large library of Ag by virtue of common structural motifs present in peptides derived from phylogenetically unrelated proteins....

  18. A Review of Antioxidant Peptides Derived from Meat Muscle and By-Products

    Directory of Open Access Journals (Sweden)

    Rui Liu

    2016-09-01

    Full Text Available Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded as good materials for the production of bioactive peptides by use of enzymatic hydrolysis or direct solvent extraction. In recent years, there has been a growing number of studies conducted to characterize antioxidant peptides or hydrolysates derived from meat muscle and by-products as well as processed meat products, including dry-cured hams. Antioxidant peptides obtained from animal sources could exert not only nutritional value but also bioavailability to benefit human health. This paper reviews the antioxidant peptides or protein hydrolysates identified in muscle protein and by-products. We focus on the procedure for the generation of peptides with antioxidant capacity including the acquisition of crude peptides, the assessment of antioxidant activity, and the purification and identification of the active fraction. It remains critical to perform validation experiments with a cell model, animal model or clinical trial to eliminate safety concerns before final application in the food system. In addition, some of the common characteristics on structure-activity relationship are also reviewed based on the identified antioxidant peptides.

  19. A Review of Antioxidant Peptides Derived from Meat Muscle and By-Products.

    Science.gov (United States)

    Liu, Rui; Xing, Lujuan; Fu, Qingquan; Zhou, Guang-Hong; Zhang, Wan-Gang

    2016-09-20

    Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded as good materials for the production of bioactive peptides by use of enzymatic hydrolysis or direct solvent extraction. In recent years, there has been a growing number of studies conducted to characterize antioxidant peptides or hydrolysates derived from meat muscle and by-products as well as processed meat products, including dry-cured hams. Antioxidant peptides obtained from animal sources could exert not only nutritional value but also bioavailability to benefit human health. This paper reviews the antioxidant peptides or protein hydrolysates identified in muscle protein and by-products. We focus on the procedure for the generation of peptides with antioxidant capacity including the acquisition of crude peptides, the assessment of antioxidant activity, and the purification and identification of the active fraction. It remains critical to perform validation experiments with a cell model, animal model or clinical trial to eliminate safety concerns before final application in the food system. In addition, some of the common characteristics on structure-activity relationship are also reviewed based on the identified antioxidant peptides.

  20. 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.

  1. Studies on lactoferricin-derived Escherichia coli membrane-active peptides reveal differences in the mechanism of N-acylated versus nonacylated peptides.

    Science.gov (United States)

    Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

    2011-06-17

    To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis.

  2. Studies on Lactoferricin-derived Escherichia coli Membrane-active Peptides Reveal Differences in the Mechanism of N-Acylated Versus Nonacylated Peptides*

    Science.gov (United States)

    Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E.; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

    2011-01-01

    To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of Gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis. PMID:21515687

  3. 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.

  4. Thiol-disulfide exchange in peptides derived from human growth hormone.

    Science.gov (United States)

    Chandrasekhar, Saradha; Epling, Daniel E; Sophocleous, Andreas M; Topp, Elizabeth M

    2014-04-01

    Disulfide bonds stabilize proteins by cross-linking distant regions into a compact three-dimensional structure. They can also participate in hydrolytic and oxidative pathways to form nonnative disulfide bonds and other reactive species. Such covalent modifications can contribute to protein aggregation. Here, we present experimental data for the mechanism of thiol-disulfide exchange in tryptic peptides derived from human growth hormone in aqueous solution. Reaction kinetics was monitored to investigate the effect of pH (6.0-10.0), temperature (4-50°C), oxidation suppressants [ethylenediaminetetraacetic acid (EDTA) and N2 sparging], and peptide secondary structure (amide cyclized vs. open form). The concentrations of free thiol containing peptides, scrambled disulfides, and native disulfide-linked peptides generated via thiol-disulfide exchange and oxidation reactions were determined using reverse-phase HPLC and liquid chromatography-mass spectrometry. Concentration versus time data were fitted to a mathematical model using nonlinear least squares regression analysis. At all pH values, the model was able to fit the data with R(2) ≥ 0.95. Excluding oxidation suppressants (EDTA and N2 sparging) resulted in an increase in the formation of scrambled disulfides via oxidative pathways but did not influence the intrinsic rate of thiol-disulfide exchange. In addition, peptide secondary structure was found to influence the rate of thiol-disulfide exchange. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    International Nuclear Information System (INIS)

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-01-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

  6. A general strategy to endow natural fusion-protein-derived peptides with potent antiviral activity.

    Directory of Open Access Journals (Sweden)

    Antonello Pessi

    Full Text Available Fusion between the viral and target cell membranes is an obligatory step for the infectivity of all enveloped virus, and blocking this process is a clinically validated therapeutic strategy.Viral fusion is driven by specialized proteins which, although specific to each virus, act through a common mechanism, the formation of a complex between two heptad repeat (HR regions. The HR regions are initially separated in an intermediate termed "prehairpin", which bridges the viral and cell membranes, and then fold onto each other to form a 6-helical bundle (6HB, driving the two membranes to fuse. HR-derived peptides can inhibit viral infectivity by binding to the prehairpin intermediate and preventing its transition to the 6HB.The antiviral activity of HR-derived peptides differs considerably among enveloped viruses. For weak inhibitors, potency can be increased by peptide engineering strategies, but sequence-specific optimization is time-consuming. In seeking ways to increase potency without changing the native sequence, we previously reported that attachment to the HR peptide of a cholesterol group ("cholesterol-tagging" dramatically increases its antiviral potency, and simultaneously increases its half-life in vivo. We show here that antiviral potency may be increased by combining cholesterol-tagging with dimerization of the HR-derived sequence, using as examples human parainfluenza virus, Nipah virus, and HIV-1. Together, cholesterol-tagging and dimerization may represent strategies to boost HR peptide potency to levels that in some cases may be compatible with in vivo use, possibly contributing to emergency responses to outbreaks of existing or novel viruses.

  7. PURIFICATION OF ANGIOTENSIN CONVERTING ENZYME INHIBITORY PEPTIDE DERIVED FROM KACANG GOAT MEAT PROTEIN HYDROLYSATE

    Directory of Open Access Journals (Sweden)

    J. Jamhari

    2014-10-01

    Full Text Available The objective of this study was to identify the Angiotensin Converting Enzyme (ACE inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC using a Cosmosil column 5PE-SM, 4.6 x 250 mm. The sequence of amino acid of ACEinhibitory peptide was identified by amino acid sequencer. The results showed that amino acidssequence of ACE inhibitory peptide derived from protein hydrolysate of Kacang goat meat was leu-thrglu-ala-pro-leu-asn-pro-lys-ala-arg- asn-glu-lys. It had a molecular weight (MW of 1581 and occurredat the position of 20th to 33rd residues of b-actin of goat meat protein (Capra hircus. The ACE inhibitoryactivity (IC50 of the peptide was 190 mg/mL or 120 mM.

  8. Refinement of glucagon-like peptide 1 docking to its intact receptor using mid-region photolabile probes and molecular modeling.

    Science.gov (United States)

    Miller, Laurence J; Chen, Quan; Lam, Polo C-H; Pinon, Delia I; Sexton, Patrick M; Abagyan, Ruben; Dong, Maoqing

    2011-05-06

    The glucagon-like peptide 1 (GLP1) receptor is an important drug target within the B family of G protein-coupled receptors. Its natural agonist ligand, GLP1, has incretin-like actions and the receptor is a recognized target for management of type 2 diabetes mellitus. Despite recent solution of the structure of the amino terminus of the GLP1 receptor and several close family members, the molecular basis for GLP1 binding to and activation of the intact receptor remains unclear. We previously demonstrated molecular approximations between amino- and carboxyl-terminal residues of GLP1 and its receptor. In this work, we study spatial approximations with the mid-region of this peptide to gain insights into the orientation of the intact receptor and the ligand-receptor complex. We have prepared two new photolabile probes incorporating a p-benzoyl-l-phenylalanine into positions 16 and 20 of GLP1(7-36). Both probes bound to the GLP1 receptor specifically and with high affinity. These were each fully efficacious agonists, stimulating cAMP accumulation in receptor-bearing CHO cells in a concentration-dependent manner. Each probe specifically labeled a single receptor site. Protease cleavage and radiochemical sequencing identified receptor residue Leu(141) above transmembrane segment one as its site of labeling for the position 16 probe, whereas the position 20 probe labeled receptor residue Trp(297) within the second extracellular loop. Establishing ligand residue approximation with this loop region is unique among family members and may help to orient the receptor amino-terminal domain relative to its helical bundle region.

  9. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A

    2014-04-18

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  10. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A; Kunze, Angelika; Carlsson, Nils; Altgä rde, Noomi; Svedhem, Sofia; Nordé n, Bengt

    2014-01-01

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  11. Lacto-ghrestatin, a novel bovine milk-derived peptide, suppresses ghrelin secretion.

    Science.gov (United States)

    Aoki, Hayato; Nakato, Junya; Mizushige, Takafumi; Iwakura, Hiroshi; Sato, Masaru; Suzuki, Hideyuki; Kanamoto, Ryuhei; Ohinata, Kousaku

    2017-07-01

    Ghrelin, an endogenous peptide isolated from the stomach, is known to stimulate food intake after peripheral administration. We found that the enzymatic digest of β-lactoglobulin decreases ghrelin secretion from the ghrelin-producing cell line MGN3-1. The peptides present in the digest were comprehensively analyzed using the nanoLC-OrbitrapMS. Among them, we identified that the nonapeptide LIVTQTMKG, corresponding to β-lactoglobulin(1-9), suppresses ghrelin secretion from MGN3-1 cells. We named LIVTQTMKG 'lacto-ghrestatin'. We found that lacto-ghrestatin decreases intracellular cAMP levels and mRNA expression levels of ghrelin production-related genes in MGN3-1 cells. Orally administered lacto-ghrestatin decreases plasma ghrelin levels and food intake in fasted mice. Lacto-ghrestatin is the first food-derived peptide to suppress ghrelin secretion in vitro and in vivo. © 2017 Federation of European Biochemical Societies.

  12. [The Qualitative Analysis of the Amide Derivative of HLDF-6 Peptide and Its Metabolites with the Use of Tritium- and Deuterium-Labeled Derivatives].

    Science.gov (United States)

    Zolotarev, A; Dadayan, A K; Kost, N V; Voevodina, M E; Sokolov, O Y; Kozik, V S; Shram, S I; Azev, V N; Bocharov, E V; Bogachouk, A P; Lipkin, V M; Myasoedov, N F

    2015-01-01

    The goal of the study was to elaborate the pharmacokinetics methods of the amide derivative of peptide HLDF-6 (TGENHR-NH2) and its range of nootropic and neuroprotective activity is wide. The hexapeptide 41TGENHR46 is a fragment of the HDLF differentiation factor. It forms the basis for the development of preventive and therapeutic preparations for treating cerebrovascular and neurodegenerative conditions. Pharmacokinetic and molecular mechanisms of the action of the HLDF-6 peptide were studied using tritium- and deuterium-labeled derivatives of this peptide, produced with the use of the high-temperature solid-state catalytic isotope exchange reaction (HSCIE). This reaction was employed to produce the tritium-labeled peptide [3H]TGENHR-NH2 with a molar radioactivity of 230 Ci/mmol and the deuterium-labeled peptide [2H]TGENHR-NH2 with an average deuterium incorporation equal to 10.5 atoms. It was shown by the NMR spectroscopy that the isotope label distribution over the labeled peptide's molecule was uniform, which allowed qualitative analysis ofboth the peptide itself and its fragments in the organism's tissues to be conducted. The newly developed pharmacokinetics method makes it possible to avoid almost completely losses of the peptides under study due to biodegradation during the analysis of tissues. These labeled peptides were used in mice, rats and rabbits to study the pharmacokinetics of the peptide and to calculate the values of its principal pharmacokinetic parameters. Characteristics of its pharmacokinetic profile in the blood were obtained, the hypothesis of pharmacokinetics linearity tested, its metabolism analyzed and its bioavailability value, 34%, calculated. It has been shown that the studied TGENHR-NH2 peptide shows high resistance to hydrolysis in the blood plasma, with dipeptidyl aminopeptidases making the largest contribution to its hydrolysis.

  13. Selective detection of carbohydrates and their peptide conjugates by ESI-MS using synthetic quaternary ammonium salt derivatives of phenylboronic acids.

    Science.gov (United States)

    Kijewska, Monika; Kuc, Adam; Kluczyk, Alicja; Waliczek, Mateusz; Man-Kupisinska, Aleksandra; Lukasiewicz, Jolanta; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2014-06-01

    We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

  14. 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...

  15. 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

  16. Structure-function characterization and optimization of a plant-derived antibacterial peptide.

    Science.gov (United States)

    Suarez, Mougli; Haenni, Marisa; Canarelli, Stéphane; Fisch, Florian; Chodanowski, Pierre; Servis, Catherine; Michielin, Olivier; Freitag, Ruth; Moreillon, Philippe; Mermod, Nicolas

    2005-09-01

    Crushed seeds of the Moringa oleifera tree have been used traditionally as natural flocculants to clarify drinking water. We previously showed that one of the seed peptides mediates both the sedimentation of suspended particles such as bacterial cells and a direct bactericidal activity, raising the possibility that the two activities might be related. In this study, the conformational modeling of the peptide was coupled to a functional analysis of synthetic derivatives. This indicated that partly overlapping structural determinants mediate the sedimentation and antibacterial activities. Sedimentation requires a positively charged, glutamine-rich portion of the peptide that aggregates bacterial cells. The bactericidal activity was localized to a sequence prone to form a helix-loop-helix structural motif. Amino acid substitution showed that the bactericidal activity requires hydrophobic proline residues within the protruding loop. Vital dye staining indicated that treatment with peptides containing this motif results in bacterial membrane damage. Assembly of multiple copies of this structural motif into a branched peptide enhanced antibacterial activity, since low concentrations effectively kill bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells. This study thus identifies a synthetic peptide with potent antibacterial activity against specific human pathogens. It also suggests partly distinct molecular mechanisms for each activity. Sedimentation may result from coupled flocculation and coagulation effects, while the bactericidal activity would require bacterial membrane destabilization by a hydrophobic loop.

  17. Advantages of the first-derivative probe technique over the three- and four-parameter probe techniques in fusion plasmas diagnostics

    Czech Academy of Sciences Publication Activity Database

    Hasan, E.; Dimitrova, Miglena; Popov, T.; Ivanova, P.; Dejarnac, Renaud; Stöckel, Jan; Pánek, Radomír

    2018-01-01

    Roč. 13, č. 4 (2018), č. článku P04005. ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LM2015045 Institutional support: RVO:61389021 Keywords : Plasma potential * electron temperature * bi-Maxwellian EEDF * Divertor Langmuir probes * three- and four-parameter probe techniques * first-derivative probe technique Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/13/04/P04005/meta

  18. Structural and pharmacological characteristics of chimeric peptides derived from peptide E and beta-endorphin reveal the crucial role of the C-terminal YGGFL and YKKGE motifs in their analgesic properties.

    Science.gov (United States)

    Condamine, Eric; Courchay, Karine; Rego, Jean-Claude Do; Leprince, Jérôme; Mayer, Catherine; Davoust, Daniel; Costentin, Jean; Vaudry, Hubert

    2010-05-01

    Peptide E (a 25-amino acid peptide derived from proenkephalin A) and beta-endorphin (a 31-amino acid peptide derived from proopiomelanocortin) bind with high affinity to opioid receptors and share structural similarities but induce analgesic effects of very different intensity. Indeed, whereas they possess the same N-terminus Met-enkephalin message sequence linked to a helix by a flexible spacer and a C-terminal part in random coil conformation, in contrast with peptide E, beta-endorphin produces a profound analgesia. To determine the key structural elements explaining this very divergent opioid activity, we have compared the structural and pharmacological characteristics of several chimeric peptides derived from peptide E and beta-endorphin. Structures were obtained under the same experimental conditions using circular dichroism, computational estimation of helical content and/or nuclear magnetic resonance spectroscopy (NMR) and NMR-restrained molecular modeling. The hot-plate and writhing tests were used in mice to evaluate the antinociceptive effects of the peptides. Our results indicate that neither the length nor the physicochemical profile of the spacer plays a fundamental role in analgesia. On the other hand, while the functional importance of the helix cannot be excluded, the last 5 residues in the C-terminal part seem to be crucial for the expression or absence of the analgesic activity of these peptides. These data raise the question of the true function of peptides E in opioidergic systems. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  19. 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.

  20. Processing of pro-opiomelanocortin-derived amidated joining peptide and glycine-extended precursor in monkey pituitary

    DEFF Research Database (Denmark)

    Fenger, M

    1991-01-01

    The molecular forms of proopiomelanocortin (POMC) derived amidated and C-terminal glycine-extended joining peptide from monkey (Macaca mulatta) pituitary were determined. The predominant forms of joining peptide found were the low molecular peptides POMC(76-105) and POMC(76-106), respectively...... sequence of monkey and human POMC extremely conserved, but also the processing patterns are similar. The monkey therefore serves as a suitable model for studying regulation of the processing of POMC and the hypothalamus-pituitary-adrenal axis in man....

  1. Monitoring multiple myeloma by idiotype-specific peptide binders of tumor-derived exosomes.

    Science.gov (United States)

    Iaccino, Enrico; Mimmi, Selena; Dattilo, Vincenzo; Marino, Fabiola; Candeloro, Patrizio; Di Loria, Antonio; Marimpietri, Danilo; Pisano, Antonio; Albano, Francesco; Vecchio, Eleonora; Ceglia, Simona; Golino, Gaetanina; Lupia, Antonio; Fiume, Giuseppe; Quinto, Ileana; Scala, Giuseppe

    2017-10-13

    Tumor-derived exosomes (TDEs) play a pivotal role in tumor establishment and progression, and are emerging biomarkers for tumor diagnosis in personalized medicine. To date, there is a lack of efficient technology platforms for exosome isolation and characterization. Multiple myeloma (MM) is an incurable B-cell malignancy due to the rapid development of drug-resistance. MM-released exosomes express the immunoglobulin B-cell receptor (Ig-BCR) of the tumor B-cells, which can be targeted by Idiotype-binding peptides (Id-peptides). In this study, we analyzed the production of MM-released exosomes in the murine 5T33MM multiple myeloma model as biomarkers of tumor growth. To this end, we selected Id-peptides by screening a phage display library using as bait the Ig-BCR expressed by 5T33MM cells. By FACS, the FITC-conjugated Id-peptides detected the MM-released exosomes in the serum of 5T33MM-engrafted mice, levels of which are correlated with tumor progression at an earlier time point compared to serum paraprotein. These results indicate that Id-peptide-based recognition of MM-released exosomes may represent a very sensitive diagnostic approach for clinical evaluation of disease progression.

  2. Antiinflammatory properties of a peptide derived from interleukin-4

    DEFF Research Database (Denmark)

    Klementiev, Boris; Enevoldsen, Maj N; Li, Shizhong

    2013-01-01

    Interleukin-4 (IL-4) is a potent antiinflammatory cytokine. However its use in the clinic is hampered by side effects. We here describe the identification of a novel synthetic peptide, termed Ph8, derived from α-helix C of IL-4, which interacts with IL-4 receptor α (IL-4Rα). Employing various...... and reduced acute inflammation in carrageenan-induced edema. Our findings indicate that Ph8 is a promising potential drug candidate for the treatment of inflammatory diseases....

  3. 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

  4. Solid-Phase Reactions of Iminium Ions: Cyclized Peptide Derivatives

    DEFF Research Database (Denmark)

    Wang, Yuanyuan

    formation of N,N’-aminals by nucleophilic attack of the peptide backbone is reversible under strongly acidic conditions and the N,N’-aminal is likely to be the kinetic product of many INCIC reactions. In addition, the N,N’-aminals are stable in the absence of acid but could be converted to the THIQ...... derivatives in solution phase under acid conditions in the presence of an active C-nucleophile in the side chain. The high yielding nature of the aminal formation is confirmed by solution phase synthesis. The introduced azide and alkyne residues in the side chain of N,N’-aminal products were further......BB may undergo auto-oxidation to quinazoline-2,4-diones in the absence of a suitable nucleophile on the side chain or backbone of the peptide (Chapter 4). The structure is confirmed by comparison with products obtained from solution-phase synthesis under the same conditions, one of which was confirmed...

  5. Antimicrobial efficacy of granulysin-derived synthetic peptides in acne vulgaris.

    Science.gov (United States)

    Lim, Hee-Sun; Chun, Seung-Min; Soung, Min-Gyu; Kim, Jenny; Kim, Seong-Jin

    2015-07-01

    Antimicrobial peptides are considered as a potential alternative to antibiotic treatment in acne vulgaris because the development of a resistant strain of Propionibacterium acnes is problematic. Granulysin can be regarded as an ideal substance with which to treat acne because it has antimicrobial and anti-inflammatory effects. This study was performed to explore the effectiveness of granulysin-derived peptides (GDPs) in killing P. acnes in vitro under a standard microbiologic assay and to evaluate their potential use in a topical agent for the treatment of acne vulgaris. Twenty different peptides based on the known sequence of a GDP were synthesized and tested in vitro for antimicrobial activity. Thirty patients with facial acne vulgaris were instructed to apply a topical formulation containing synthetic GDP to acne lesions twice per day for 12 weeks. A newly synthesized peptide in which aspartic acid was substituted with arginine, and methionine was substituted with cysteine, showed the highest antimicrobial activity against P. acnes. Moreover, it was effective against both Gram-positive and Gram-negative bacteria in vitro. After treatment with the topical formulation containing 50 ppm of synthetic peptide for 12 weeks, a significant reduction in the number of pustules was observed, regardless of the increase in the number of comedones. In addition, a significant reduction in the clinical grade of acne based on the Korean Acne Grading System (KAGS) was evident. Synthesized GDP shows strong antimicrobial activity against P. acnes in vitro. The clinical improvement observed suggests a topical formulation containing the GDP has therapeutic potential for the improvement of inflammatory-type acne vulgaris by its antimicrobial activity. © 2015 The International Society of Dermatology.

  6. Screening of soy protein-derived hypotriglyceridemic di-peptides in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Matsui Toshiro

    2011-05-01

    Full Text Available Abstract Background Soy protein and soy peptides have attracted considerable attention because of their potentially beneficial biological properties, including antihypertensive, anticarcinogenic, and hypolipidemic effects. Although soy protein isolate contains several bioactive peptides that have distinct physiological activities in lipid metabolism, it is not clear which peptide sequences are responsible for the triglyceride (TG-lowering effects. In the present study, we investigated the effects of soy protein-derived peptides on lipid metabolism, especially TG metabolism, in HepG2 cells and obese Otsuka Long-Evans Tokushima fatty (OLETF rats. Results In the first experiment, we found that soy crude peptide (SCP-LD3, which was prepared by hydrolyze of soy protein isolate with endo-type protease, showed hypolipidemic effects in HepG2 cells and OLETF rats. In the second experiment, we found that hydrophilic fraction, separated from SCP-LD3 with hydrophobic synthetic absorbent, revealed lipid-lowering effects in HepG2 cells and OLETF rats. In the third experiment, we found that Fraction-C (Frc-C peptides, fractionated from hydrophilic peptides by gel permeation chromatography-high performance liquid chromatography, significantly reduced TG synthesis and apolipoprotein B (apoB secretion in HepG2 cells. In the fourth experiment, we found that the fraction with 0.1% trifluoroacetic acid, isolated from Frc-C peptides by octadecylsilyl column chromatography, showed hypolipidemic effects in HepG2 cells. In the final experiment, we found that 3 di-peptides, Lys-Ala, Val-Lys, and Ser-Tyr, reduced TG synthesis, and Ser-Tyr additionally reduced apoB secretion in HepG2 cells. Conclusion Novel active peptides with TG-lowering effects from soy protein have been isolated.

  7. 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.

  8. Effects of lactoferrin derived peptides on simulants of biological warfare agents.

    Science.gov (United States)

    Sijbrandij, Tjitske; Ligtenberg, Antoon J; Nazmi, Kamran; Veerman, Enno C I; Bolscher, Jan G M; Bikker, Floris J

    2017-01-01

    Lactoferrin (LF) is an important immune protein in neutrophils and secretory fluids of mammals. Bovine LF (bLF) harbours two antimicrobial stretches, lactoferricin and lactoferampin, situated in close proximity in the N1 domain. To mimic these antimicrobial domain parts a chimeric peptide (LFchimera) has been constructed comprising parts of both stretches (LFcin17-30 and LFampin265-284). To investigate the potency of this construct to combat a set of Gram positive and Gram negative bacteria which are regarded as simulants for biological warfare agents, the effect on bacterial killing, membrane permeability and membrane polarity were determined in comparison to the constituent peptides and the native bLF. Furthermore we aimed to increase the antimicrobial potency of the bLF derived peptides by cationic amino acid substitutions. Overall, the bactericidal activity of the peptides could be related to membrane disturbing effects, i.e. membrane permeabilization and depolarization. Those effects were most prominent for the LFchimera. Arginine residues were found to be crucial for displaying antimicrobial activity, as lysine to arginine substitutions resulted in an increased antimicrobial activity, affecting mostly LFampin265-284 whereas arginine to lysine substitutions resulted in a decreased bactericidal activity, predominantly in case of LFcin17-30.

  9. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

    Directory of Open Access Journals (Sweden)

    Praveen Papareddy

    Full Text Available Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2. This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  10. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

    Science.gov (United States)

    Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

    2013-01-01

    Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2). This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  11. Neutrophil elastase and elastin-derived peptides in BAL fluid and emphysematous changes on CT scans

    International Nuclear Information System (INIS)

    Betsuyaku, Tomoko; Nishimura, Masaharu; Yoshioka, Aya; Takeyabu, Kimihiro; Miyamoto, Kenji; Kawakami, Yoshikazu

    1996-01-01

    We examined the relationship between neutrophil elastase, elastin-derived peptides in bronchoalveolar lavage (BAL) fluid, and the development of pulmonary emphysema. The level of neutrophil elastase was higher in asymptomatic current smokers with emphysematous changes on computed tomographic scans than in current smokers without emphysematous changes, and was found to be correlated with the level of elastin-derived peptides in BAL fluid. Subjects with high levels of neutrophil elastase in BAL fluid had faster annual declines in FEV 1 . We conclude that the level of neutrophil elastase in BAL fluid can be used to differentiate asymptomatic cigarette smokers who are at risk for pulmonary emphysema from those who are not. (author)

  12. Venom-derived peptides inhibiting Kir channels: Past, present, and future.

    Science.gov (United States)

    Doupnik, Craig A

    2017-12-01

    Inwardly rectifying K + (Kir) channels play a significant role in vertebrate and invertebrate biology by regulating the movement of K + ions involved in membrane transport and excitability. Yet unlike other ion channels including their ancestral K + -selective homologs, there are very few venom toxins known to target and inhibit Kir channels with the potency and selectivity found for the Ca 2+ -activated and voltage-gated K + channel families. It is unclear whether this is simply due to a lack of discovery, or instead a consequence of the evolutionary processes that drive the development of venom components towards their targets based on a collective efficacy to 1) elicit pain for defensive purposes, 2) promote paralysis for prey capture, or 3) facilitate delivery of venom components into the circulation. The past two decades of venom screening has yielded three venom peptides with inhibitory activity towards mammalian Kir channels, including the discovery of tertiapin, a high-affinity pore blocker from the venom of the European honey bee Apis mellifera. Venomics and structure-based computational approaches represent exciting new frontiers for venom peptide development, where re-engineering peptide 'scaffolds' such as tertiapin may aid in the quest to expand the palette of potent and selective Kir channel blockers for future research and potentially new therapeutics. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.' Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Rapid identification of Staphylococcus aureus and methicillin resistance by flow cytometry using a peptide nucleic acid probe.

    Science.gov (United States)

    Shrestha, Nabin K; Scalera, Nikole M; Wilson, Deborah A; Brehm-Stecher, Byron; Procop, Gary W

    2011-09-01

    A total of 56 Staphylococcus aureus isolates incubated for 2 h in the presence or absence of oxacillin were analyzed by flow cytometry after labeling with an S. aureus-specific peptide nucleic acid (PNA) probe. Two defined ratios, the paired signal count ratio (PSCR) and the gate signal count ratio (GSCR), differentiated methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) with sensitivities of 100% each and specificities of 96% and 100%, respectively.

  14. Enhancement of endotoxin neutralization by coupling of a C12-alkyl chain to a lactoferricin-derived peptide

    Science.gov (United States)

    2004-01-01

    Antibacterial peptide acylation, which mimics the structure of the natural lipopeptide polymyxin B, increases antimicrobial and endotoxin-neutralizing activities. The interaction of the lactoferricin-derived peptide LF11 and its N-terminally acylated analogue, lauryl-LF11, with different chemotypes of bacterial lipopolysaccharide (LPS Re, Ra and smooth S form) was investigated by biophysical means and was related to the peptides' biological activities. Both peptides exhibit high antibacterial activity against the three strains of Salmonella enterica differing in the LPS chemotype. Lauryl-LF11 has one order of magnitude higher activity against Re-type, but activity against Ra- and S-type bacteria is comparable with that of LF11. The alkyl derivative peptide lauryl-LF11 shows a much stronger inhibition of the LPS-induced cytokine induction in human mononuclear cells than LF11. Although peptide–LPS interaction is essentially of electrostatic nature, the lauryl-modified peptide displays a strong hydrophobic component. Such a feature might then explain the fact that saturation of the peptide binding takes place at a much lower peptide/LPS ratio for LF11 than for lauryl-LF11, and that an overcompensation of the negative LPS backbone charges is observed for lauryl-LF11. The influence of LF11 on the gel-to-liquid-crystalline phase-transition of LPS is negligible for LPS Re, but clearly fluidizing for LPS Ra. In contrast, lauryl-LF11 causes a cholesterol-like effect in the two chemotypes, fluidizing in the gel and rigidifying of the hydrocarbon chains in the liquid-crystalline phase. Both peptides convert the mixed unilamellar/non-lamellar aggregate structure of lipid A, the ‘endotoxic principle’ of LPS, into a multilamellar one. These data contribute to the understanding of the mechanisms of the peptide-mediated neutralization of endotoxin and effect of lipid modification of peptides. PMID:15344905

  15. Proteolytic signatures define unique thrombin-derived peptides present in human wound fluid in vivo.

    Science.gov (United States)

    Saravanan, Rathi; Adav, Sunil S; Choong, Yeu Khai; van der Plas, Mariena J A; Petrlova, Jitka; Kjellström, Sven; Sze, Siu Kwan; Schmidtchen, Artur

    2017-10-13

    The disease burden of failing skin repair and non-healing ulcers is extensive. There is an unmet need for new diagnostic approaches to better predict healing activity and wound infection. Uncontrolled and excessive protease activity, of endogenous or bacterial origin, has been described as a major contributor to wound healing impairments. Proteolytic peptide patterns could therefore correlate and "report" healing activity and infection. This work describes a proof of principle delineating a strategy by which peptides from a selected protein, human thrombin, are detected and attributed to proteolytic actions. With a particular focus on thrombin-derived C-terminal peptides (TCP), we show that distinct peptide patterns are generated in vitro by the human S1 peptidases human neutrophil elastase and cathepsin G, and the bacterial M4 peptidases Pseudomonas aeruginosa elastase and Staphylococcus aureus aureolysin, respectively. Corresponding peptide sequences were identified in wound fluids from acute and non-healing ulcers, and notably, one peptide, FYT21 (FYTHVFRLKKWIQKVIDQFGE), was only present in wound fluid from non-healing ulcers colonized by P. aeruginosa and S. aureus. Our result is a proof of principle pointing at the possibility of defining peptide biomarkers reporting distinct proteolytic activities, of potential implication for improved diagnosis of wound healing and infection.

  16. Probing the role of backbone hydrogen bonds in protein-peptide interactions by amide-to-ester mutations

    DEFF Research Database (Denmark)

    Eildal, Jonas N N; Hultqvist, Greta; Balle, Thomas

    2013-01-01

    -protein interactions, those of the PDZ domain family involve formation of intermolecular hydrogen bonds: C-termini or internal linear motifs of proteins bind as β-strands to form an extended antiparallel β-sheet with the PDZ domain. Whereas extensive work has focused on the importance of the amino acid side chains...... of the protein ligand, the role of the backbone hydrogen bonds in the binding reaction is not known. Using amide-to-ester substitutions to perturb the backbone hydrogen-bonding pattern, we have systematically probed putative backbone hydrogen bonds between four different PDZ domains and peptides corresponding...... to natural protein ligands. Amide-to-ester mutations of the three C-terminal amides of the peptide ligand severely affected the affinity with the PDZ domain, demonstrating that hydrogen bonds contribute significantly to ligand binding (apparent changes in binding energy, ΔΔG = 1.3 to >3.8 kcal mol(-1...

  17. Antibacterial activity of synthetic peptides derived from lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212.

    Science.gov (United States)

    León-Calvijo, María A; Leal-Castro, Aura L; Almanzar-Reina, Giovanni A; Rosas-Pérez, Jaiver E; García-Castañeda, Javier E; Rivera-Monroy, Zuly J

    2015-01-01

    Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2Ahx2C2) exhibit bigger or similar activity against E. coli (MIC 4-33 μM) and E. faecalis (MIC 10-33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

  18. Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212

    Directory of Open Access Journals (Sweden)

    María A. León-Calvijo

    2015-01-01

    Full Text Available Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i the incorporation of unnatural amino acids in the sequence, the (ii reduction or (iii elongation of the peptide chain length, and (iv synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR and I.4 ((RRWQWR4K2Ahx2C2 exhibit bigger or similar activity against E. coli (MIC 4–33 μM and E. faecalis (MIC 10–33 μM when they were compared with lactoferricin protein (LF and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE. It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

  19. Iodinated derivatives of vasoactive intestinal peptide (VIP), PHI and PHM: purification, chemical characterization and biological activity

    International Nuclear Information System (INIS)

    McMaster, D.; Suzuki, Y.; Rorstad, O.; Lederis, K.

    1987-01-01

    The iodination of vasoactive intestinal peptide (VIP) was studied, using a variety of enzymatic and chemical iodination methods. Reversed phase high performance liquid chromatography (HPLC) was used to purify the reaction products. The lactoperoxidase-glucose oxidase method gave excellent results in terms of reproducibility, iodine incorporation, and yield of the non-oxidized products [Tyr(I)10]VIP and [Tyr(I)22]VIP, and was used to prepare both 125 I and 127 I labelled derivatives. In both cases, direct application to HPLC and a single column system were used. Although the oxidized peptides [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP could be generated to varying degrees directly by iodination of VIP, these were most conveniently prepared by iodination of [Met(O)17]VIP. Iodinated derivatives of the homologous peptides PHI and PHM were likewise prepared by rapid, one-step HPLC procedures. The site and degree of iodination were determined by HPLC peptide mapping of tryptic digests and amino acid analyses, and in the case of [Tyr(I)10]VIP also by sequencing. The vasorelaxant activities of the iodinated peptides in bovine cerebral artery preparations did not differ significantly from those of the corresponding noniodinated peptides, with the exception of [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP which, unlike [Met(O)17]VIP itself, had slightly lower potency than VIP

  20. Antimicrobial activity of synthetic cationic peptides and lipopeptides derived from human lactoferricin against Pseudomonas aeruginosa planktonic cultures and biofilms.

    Science.gov (United States)

    Sánchez-Gómez, Susana; Ferrer-Espada, Raquel; Stewart, Philip S; Pitts, Betsey; Lohner, Karl; Martínez de Tejada, Guillermo

    2015-07-07

    Infections by Pseudomonas aeruginosa constitute a serious health threat because this pathogen -particularly when it forms biofilms - can acquire resistance to the majority of conventional antibiotics. This study evaluated the antimicrobial activity of synthetic peptides based on LF11, an 11-mer peptide derived from human lactoferricin against P. aeruginosa planktonic and biofilm-forming cells. We included in this analysis selected N-acylated derivatives of the peptides to analyze the effect of acylation in antimicrobial activity. To assess the efficacy of compounds against planktonic bacteria, microdilution assays to determine the minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill studies were conducted. The anti-biofilm activity of the agents was assessed on biofilms grown under static (on microplates) and dynamic (in a CDC-reactor) flow regimes. The antimicrobial activity of lipopeptides differed from that of non-acylated peptides in their killing mechanisms on planktonic and biofilm-forming cells. Thus, acylation enhanced the bactericidal activity of the parental peptides and resulted in lipopeptides that were uniformly bactericidal at their MIC. In contrast, acylation of the most potent anti-biofilm peptides resulted in compounds with lower anti-biofilm activity. Both peptides and lipopeptides displayed very rapid killing kinetics and all of them required less than 21 min to reduce 1,000 times the viability of planktonic cells when tested at 2 times their MBC. The peptides, LF11-215 (FWRIRIRR) and LF11-227 (FWRRFWRR), displayed the most potent anti-biofilm activity causing a 10,000 fold reduction in cell viability after 1 h of treatment at 10 times their MIC. At that concentration, these two compounds exhibited low citotoxicity on human cells. In addition to its bactericidal activity, LF11-227 removed more that 50 % of the biofilm mass in independent assays. Peptide LF11-215 and two of the shortest and least

  1. Three-Dimensional Graphene–RGD Peptide Nanoisland Composites That Enhance the Osteogenesis of Human Adipose-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Ee-Seul Kang

    2018-02-01

    Full Text Available Graphene derivatives have immense potential in stem cell research. Here, we report a three-dimensional graphene/arginine-glycine-aspartic acid (RGD peptide nanoisland composite effective in guiding the osteogenesis of human adipose-derived mesenchymal stem cells (ADSCs. Amine-modified silica nanoparticles (SiNPs were uniformly coated onto an indium tin oxide electrode (ITO, followed by graphene oxide (GO encapsulation and electrochemical deposition of gold nanoparticles. A RGD–MAP–C peptide, with a triple-branched repeating RGD sequence and a terminal cysteine, was self-assembled onto the gold nanoparticles, generating the final three-dimensional graphene–RGD peptide nanoisland composite. We generated substrates with various gold nanoparticle–RGD peptide cluster densities, and found that the platform with the maximal number of clusters was most suitable for ADSC adhesion and spreading. Remarkably, the same platform was also highly efficient at guiding ADSC osteogenesis compared with other substrates, based on gene expression (alkaline phosphatase (ALP, runt-related transcription factor 2, enzyme activity (ALP, and calcium deposition. ADSCs induced to differentiate into osteoblasts showed higher calcium accumulations after 14–21 days than when grown on typical GO-SiNP complexes, suggesting that the platform can accelerate ADSC osteoblastic differentiation. The results demonstrate that a three-dimensional graphene–RGD peptide nanoisland composite can efficiently derive osteoblasts from mesenchymal stem cells.

  2. Protease-activated quantum dot probes

    International Nuclear Information System (INIS)

    Chang, Emmanuel; Miller, Jordan S.; Sun, Jiantang; Yu, William W.; Colvin, Vicki L.; Drezek, Rebekah; West, Jennifer L.

    2005-01-01

    We have developed a novel nanoparticulate luminescent probe with inherent signal amplification upon interaction with a targeted proteolytic enzyme. This construct may be useful for imaging in cancer detection and diagnosis. In this system, quantum dots (QDs) are bound to gold nanoparticles (AuNPs) via a proteolytically degradable peptide sequence to non-radiatively suppress luminescence. A 71% reduction in luminescence was achieved with conjugation of AuNPs to QDs. Release of AuNPs by peptide cleavage restores radiative QD photoluminescence. Initial studies observed a 52% rise in luminescence over 47 h of exposure to 0.2 mg/mL collagenase. These probes can be customized for targeted degradation simply by changing the sequence of the peptide linker

  3. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    Directory of Open Access Journals (Sweden)

    Nadal Anna

    2012-09-01

    Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

  4. Stimulation of Interleukin-10 Production by Acidic β-Lactoglobulin-Derived Peptides Hydrolyzed with Lactobacillus paracasei NCC2461 Peptidases

    OpenAIRE

    Prioult, Guénolée; Pecquet, Sophie; Fliss, Ismail

    2004-01-01

    We have previously demonstrated that Lactobacillus paracasei NCC2461 may help to prevent cow's milk allergy in mice by inducing oral tolerance to β-lactoglobulin (BLG). To investigate the mechanisms involved in this beneficial effect, we examined the possibility that L. paracasei induces tolerance by hydrolyzing BLG-derived peptides and liberating peptides that stimulate interleukin-10 (IL-10) production. L. paracasei peptidases have been shown to hydrolyze tryptic-chymotryptic peptides from ...

  5. Structural properties of a peptide derived from H+-V-ATPase subunit a

    NARCIS (Netherlands)

    Vermeer, L.S.; Reat, V.; Hemminga, M.A.; Milon, A.

    2009-01-01

    The 3D structure of a peptide derived from the putative transmembrane segment 7 (TM7) of subunit a from H+-V-ATPase from Saccharomyces cerevisiae has been determined by solution state NMR in SDS. A stable helix is formed from L736 up to and including Q745, the lumenal half of the putative TM7. The

  6. A Chimeric Peptide Composed of a Dermaseptin Derivative and an RNA III-Inhibiting Peptide Prevents Graft-Associated Infections by Antibiotic-Resistant Staphylococci

    Science.gov (United States)

    Balaban, Naomi; Gov, Yael; Giacometti, Andrea; Cirioni, Oscar; Ghiselli, Roberto; Mocchegiani, Federico; Orlando, Fiorenza; D'Amato, Giuseppina; Saba, Vittorio; Scalise, Giorgio; Bernes, Sabina; Mor, Amram

    2004-01-01

    Staphylococcal bacteria are a prevalent cause of infections associated with foreign bodies and indwelling medical devices. Bacteria are capable of escaping antibiotic treatment through encapsulation into biofilms. RNA III-inhibiting peptide (RIP) is a heptapeptide that inhibits staphylococcal biofilm formation by obstructing quorum-sensing mechanisms. K4-S4(1-13)a is a 13-residue dermaseptin derivative (DD13) believed to kill bacteria via membrane disruption. We tested each of these peptides as well as a hybrid construct, DD13-RIP, for their ability to inhibit bacterial proliferation and suppress quorum sensing in vitro and for their efficacy in preventing staphylococcal infection in a rat graft infection model with methicillin-resistant Staphylococcus aureus (MRSA) or S. epidermidis (MRSE). In vitro, proliferation assays demonstrated that RIP had no inhibitory effect, while DD13-RIP and DD13 were equally effective, and that the chimeric peptide but not DD13 was slightly more effective than RIP in inhibiting RNA III synthesis, a regulatory RNA molecule important for staphylococcal pathogenesis. In vivo, the three peptides reduced graft-associated bacterial load in a dose-dependent manner, but the hybrid peptide was most potent in totally preventing staphylococcal infections at the lowest dose. In addition, each of the peptides acted synergistically with antibiotics. The data indicate that RIP and DD13 act in synergy by attacking bacteria simultaneously by two different mechanisms. Such a chimeric peptide may be useful for coating medical devices to prevent drug-resistant staphylococcal infections. PMID:15215107

  7. Penetration of Milk-Derived Antimicrobial Peptides into Phospholipid Monolayers as Model Biomembranes

    Directory of Open Access Journals (Sweden)

    Wanda Barzyk

    2013-01-01

    Full Text Available Three antimicrobial peptides derived from bovine milk proteins were examined with regard to penetration into insoluble monolayers formed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC or 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol sodium salt (DPPG. Effects on surface pressure (Π and electric surface potential (ΔV were measured, Π with a platinum Wilhelmy plate and ΔV with a vibrating plate. The penetration measurements were performed under stationary diffusion conditions and upon the compression of the monolayers. The two type measurements showed greatly different effects of the peptide-lipid interactions. Results of the stationary penetration show that the peptide interactions with DPPC monolayer are weak, repulsive, and nonspecific while the interactions with DPPG monolayer are significant, attractive, and specific. These results are in accord with the fact that antimicrobial peptides disrupt bacteria membranes (negative while no significant effect on the host membranes (neutral is observed. No such discrimination was revealed from the compression isotherms. The latter indicate that squeezing the penetrant out of the monolayer upon compression does not allow for establishing the penetration equilibrium, so the monolayer remains supersaturated with the penetrant and shows an under-equilibrium orientation within the entire compression range, practically.

  8. Improving surface functional properties of tofu whey-derived peptides by chemical modification with fatty acids.

    Science.gov (United States)

    Matemu, Athanasia Oswald; Katayama, Shigeru; Kayahara, Hisataka; Murasawa, Hisashi; Nakamura, Soichiro

    2012-04-01

    Effect of acylation with saturated fatty acids on surface functional properties of tofu whey-derived peptides was investigated. Tofu whey (TW) and soy proteins (7S, 11S, and acid-precipitated soy protein [APP]) were hydrolyzed by Protease M 'Amano' G, and resulting peptide mixtures were acylated with esterified fatty acids of different chain length (6C to 18C) to form a covalent linkage between the carboxyl group of fatty acid and the free amino groups of peptide. Acylation significantly (P properties of 7S, 11S, and APP peptides independent of fatty acid chain length. Acylation decreased water binding capacity although oil binding capacity of acylated tofu whey ultra filtered fraction (UFTW acids had shown significant higher surface hydrophobicity as in contrast with acylated UFTW acids can further affect functional properties of soy proteins. © 2012 Institute of Food Technologists®

  9. Fluorescent peptide biosensor for probing the relative abundance of cyclin-dependent kinases in living cells.

    Directory of Open Access Journals (Sweden)

    Laetitia Kurzawa

    Full Text Available Cyclin-dependant kinases play a central role in coordinating cell growth and division, and in sustaining proliferation of cancer cells, thereby constituting attractive pharmacological targets. However, there are no direct means of assessing their relative abundance in living cells, current approaches being limited to antigenic and proteomic analysis of fixed cells. In order to probe the relative abundance of these kinases directly in living cells, we have developed a fluorescent peptide biosensor with biligand affinity for CDKs and cyclins in vitro, that retains endogenous CDK/cyclin complexes from cell extracts, and that bears an environmentally-sensitive probe, whose fluorescence increases in a sensitive fashion upon recognition of its targets. CDKSENS was introduced into living cells, through complexation with the cell-penetrating carrier CADY2 and applied to assess the relative abundance of CDK/Cyclins through fluorescence imaging and ratiometric quantification. This peptide biosensor technology affords direct and sensitive readout of CDK/cyclin complex levels, and reports on differences in complex formation when tampering with a single CDK or cyclin. CDKSENS further allows for detection of differences between different healthy and cancer cell lines, thereby enabling to distinguish cells that express high levels of these heterodimeric kinases, from cells that present decreased or defective assemblies. This fluorescent biosensor technology provides information on the overall status of CDK/Cyclin complexes which cannot be obtained through antigenic detection of individual subunits, in a non-invasive fashion which does not require cell fixation or extraction procedures. As such it provides promising perspectives for monitoring the response to therapeutics that affect CDK/Cyclin abundance, for cell-based drug discovery strategies and fluorescence-based cancer diagnostics.

  10. Quantification of VGF- and pro-SAAS-derived peptides in endocrine tissues and the brain, and their regulation by diet and cold stress.

    Science.gov (United States)

    Chakraborty, Tandra R; Tkalych, Oleg; Nanno, Daniela; Garcia, Angelo L; Devi, Lakshmi A; Salton, Stephen R J

    2006-05-17

    Two novel granin-like polypeptides, VGF and pro-SAAS, which are stored in and released from secretory vesicles and are expressed widely in nervous, endocrine, and neuroendocrine tissues, play roles in the regulation of body weight, feeding, and energy expenditure. Both VGF and pro-SAAS are cleaved into peptide fragments, several of which are biologically active. We utilized a highly sensitive and specific radioimmunoassay (RIA) to immunoreactive, pro-SAAS-derived PEN peptides, developed another against immunoreactive, VGF-derived AQEE30 peptides, and quantified these peptides in various mouse tissues and brain regions. Immunoreactive AQEE30 was most abundant in the pituitary, while brain levels were highest in hypothalamus, striatum, and frontal cortex. Immunoreactive PEN levels were highest in the pancreas and spinal cord, and in brain, PEN was most abundant in striatum, hippocampus, pons and medulla, and cortex. Since both peptides were expressed in hypothalamus, a region of the brain that controls feeding and energy expenditure, double label immunofluorescence studies were employed. These demonstrated that 42% of hypothalamic arcuate neurons coexpress VGF and SAAS peptides, and that the intracellular distributions of these peptides in arcuate neurons differed. By RIA, cold stress increased immunoreactive AQEE30 and PEN peptide levels in female but not male hypothalamus, while a high fat diet increased AQEE30 and PEN peptide levels in female but not male hippocampus. VGF and SAAS-derived peptides are therefore widely expressed in endocrine, neuroendocrine, and neural tissues, can be accurately quantified by RIA, and are differentially regulated in the brain by diet and cold stress.

  11. Rapid Identification of Staphylococcus aureus and Methicillin Resistance by Flow Cytometry Using a Peptide Nucleic Acid Probe

    Science.gov (United States)

    Shrestha, Nabin K.; Scalera, Nikole M.; Wilson, Deborah A.; Brehm-Stecher, Byron; Procop, Gary W.

    2011-01-01

    A total of 56 Staphylococcus aureus isolates incubated for 2 h in the presence or absence of oxacillin were analyzed by flow cytometry after labeling with an S. aureus-specific peptide nucleic acid (PNA) probe. Two defined ratios, the paired signal count ratio (PSCR) and the gate signal count ratio (GSCR), differentiated methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) with sensitivities of 100% each and specificities of 96% and 100%, respectively. PMID:21795508

  12. Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment.

    OpenAIRE

    Yamauchi, K; Tomita, M; Giehl, T J; Ellison, R T

    1993-01-01

    Although the antimicrobial activity of lactoferrin has been well described, its mechanism of action has been poorly characterized. Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin-derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin rele...

  13. N-Acylated and d Enantiomer Derivatives of a Nonamer Core Peptide of Lactoferricin B Showing Improved Antimicrobial Activity

    OpenAIRE

    Wakabayashi, Hiroyuki; Matsumoto, Hiroshi; Hashimoto, Koichi; Teraguchi, Susumu; Takase, Mitsunori; Hayasawa, Hirotoshi

    1999-01-01

    N-acylated or d enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

  14. N-Acylated and D enantiomer derivatives of a nonamer core peptide of lactoferricin B showing improved antimicrobial activity.

    Science.gov (United States)

    Wakabayashi, H; Matsumoto, H; Hashimoto, K; Teraguchi, S; Takase, M; Hayasawa, H

    1999-05-01

    N-acylated or D enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

  15. Spontaneous human squamous cell carcinomas are killed by a human cytotoxic T lymphocyte clone recognizing a wild-type p53-derived peptide

    DEFF Research Database (Denmark)

    Röpke, M; Hald, J; Guldberg, Per

    1996-01-01

    p53 genes, in a L9V/HLA-A2 specific and restricted fashion. Thus, the normal tolerance against endogenously processed p53 protein-derived self-epitopes can be broken by peptide-specific in vitro priming. p53 protein-derived wild-type peptides might thus represent tumor associated target molecules...

  16. Chemoproteomic profiling of targets of lipid-derived electrophiles by bioorthogonal aminooxy probe

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2017-08-01

    Full Text Available Redox imbalance in cells induces lipid peroxidation and generates a class of highly reactive metabolites known as lipid-derived electrophiles (LDEs that can modify proteins and affects their functions. Identifying targets of LDEs is critical to understand how such modifications are functionally implicated in oxidative-stress associated diseases. Here we report a quantitative chemoproteomic method to globally profile protein targets and sites modified by LDEs. In this strategy, we designed and synthesized an alkyne-functionalized aminooxy probe to react with LDE-modified proteins for imaging and proteomic profiling. Using this probe, we successfully quantified >4000 proteins modified by 4-hydroxy-2-nonenal (HNE of high confidence in mammalian cell lysate and combined with a tandem-orthogonal proteolysis activity-based protein profiling (TOP-ABPP strategy, we identified ~400 residue sites targeted by HNE including reactive cysteines in peroxiredoxins, an important family of enzymes with anti-oxidant roles. Our method expands the toolbox to quantitatively profile protein targets of endogenous electrophiles and the enlarged inventory of LDE-modified proteins and sites will contribute to functional elucidation of cellular pathways affected by oxidative stress. Keywords: Lipid-derived electrophile, 4-hydroxy-2-nonenal, Chemoproteomics, Aminooxy probe, Activity-based protein profiling

  17. Apoptotic death of Listeria monocytogenes-infected human macrophages induced by lactoferricin B, a bovine lactoferrin-derived peptide.

    Science.gov (United States)

    Longhi, C; Conte, M P; Ranaldi, S; Penta, M; Valenti, P; Tinari, A; Superti, F; Seganti, L

    2005-01-01

    Listeria monocytogenes, an intracellular facultative food-borne pathogen, was reported to induce apoptosis in vitro and in vivo in a variety of cell types with the exception of murine macrophages. These cells represent the predominant compartment of bacterial multiplication and die as a result of necrosis. In this study we showed that human non-activated and IFN-gamma-activated macrophagic-like (THP-1) cells infected with L. monocytogenes, mainly die by necrosis rather than by an apoptotic process. Two natural products derived from bovine milk, lactoferrin and its derivative peptide lactoferricin B, are capable of regulating the fate of infected human macrophages. Bovine lactoferrin treatment of macrophages protects them from L. monocytogenes-induced death whereas lactoferricin B, its derivative peptide, determines a shifting of the equilibrium from necrosis to apoptosis.

  18. In Vitro and In Vivo Evaluation of Alexa Fluor 680-Bombesin[7–14]NH2 Peptide Conjugate, a High-Affinity Fluorescent Probe with High Selectivity for the Gastrin-Releasing Peptide Receptor

    Directory of Open Access Journals (Sweden)

    Lixin Ma

    2007-05-01

    Full Text Available Gastrin-releasing peptide (GRP receptors are overexpressed on several types of human cancer cells, including breast, prostate, small cell lung, and pancreatic cancers. Bombesin (BBN, a 14–amino acid peptide that is an analogue of human GRP, binds to GRP receptors with very high affinity and specificity. The aim of this study was to develop a new fluorescent probe based on BBN having high tumor uptake and optimal pharmacokinetics for specific targeting and optical imaging of human breast cancer tissue. In this study, solid-phase peptide synthesis was used to produce H2N-glycylglycylglycine-BBN[7–14]NH2 peptide with the following general sequence: H2N-G-G-G-Q-W-A-V-G-H-L-M-(NH2. This conjugate was purified by reversed-phase high-performance liquid chromatography and characterized by electrospray-ionization mass spectra. The fluorescent probe Alexa Fluor 680-G-G-G-BBN[7–14]NH2 conjugate was prepared by reaction of Alexa Fluor 680 succinimidyl ester to H2N-G-G-G-BBN[7–14]NH2 in dimethylformamide (DMF. In vitro competitive binding assays, using 125I-Tyr4-BBN as the radiolabeling gold standard, demonstrated an inhibitory concentration 50% value of 7.7 ± 1.4 nM in human T-47D breast cancer cells. Confocal fluorescence microscopy images of Alexa Fluor 680-G-G-G-BBN[7–14]NH2 in human T-47D breast cancer cells indicated specific uptake, internalization, and receptor blocking of the fluorescent bioprobe in vitro. In vivo investigations in SCID mice bearing xenografted T-47D breast cancer lesions demonstrated the ability of this new conjugate to specifically target tumor tissue with high selectivity and affinity.

  19. Comparative antimicrobial activity and mechanism of action of bovine lactoferricin-derived synthetic peptides.

    Science.gov (United States)

    Liu, Yifan; Han, Feifei; Xie, Yonggang; Wang, Yizhen

    2011-12-01

    Lactoferricin B (LfcinB), a 25 residue peptide derived from the N-terminal of bovine lactoferrin (bLF), causes depolarization of the cytoplasmic membrane in susceptible bacteria. Its mechanism of action, however, still needs to be elucidated. In the present study, synthetic LfcinB (without a disulfide bridge) and LfcinB (C-C; with a disulfide bridge) as well as three derivatives with 15-, 11- and 9-residue peptides were prepared to investigate their antimicrobial nature and mechanisms. The antimicrobial properties were measured via minimum inhibitory concentration (MIC) determinations, killing kinetics assays and synergy testing, and hemolytic activities were assessed by hemoglobin release. Finally, the morphology of peptide-treated bacteria was determined by atomic force microscopy (AFM). We found that there was no difference in MICs between LfcinB and LfcinB (C-C). Among the derivatives, only LfcinB15 maintained nearly the same level as LfcinB, in the MIC range of 16-128 μg/ml, and the MICs of LfcinB11 (64-256 μg/ml) were 4 times more than LfcinB, while LfcinB9 exhibited the lowest antimicrobial activity. When treated at MIC for 1 h, many blebs were formed and holes of various sizes appeared on the cell surface, but the cell still maintained its integrity. This suggested that LfcinB had a major permeability effect on the cytoplasmic membrane of both Gram-positive and Gram-negative bacteria, which also indicated it may be a possible intracellular target. Among the tested antibiotics, aureomycin increased the bactericidal activity of LfcinB against E. coli, S. aureus and P. aeruginosa, but neomycin did not have such an effect. We also found that the combination of cecropin A and LfcinB had synergistic effects against E. coli.

  20. Ghrelin-derived peptides: a link between appetite/reward, GH axis and psychiatric disorders ?

    Directory of Open Access Journals (Sweden)

    Alexandra eLabarthe

    2014-10-01

    Full Text Available Psychiatric disorders are often associated with metabolic and hormonal alterations, including obesity, diabetes, metabolic syndrome as well as modifications in several biological rhythms including appetite, stress, sleep-wake cycles and secretion of their corresponding endocrine regulators.Among the gastrointestinal hormones that regulate appetite and adapt the metabolism in response to nutritional, hedonic and emotional dysfunctions, at the interface between endocrine, metabolic and psychiatric disorders, ghrelin plays a unique role as the only one increasing appetite. The secretion of ghrelin is altered in several psychiatric disorders (anorexia, schizophrenia as well as in metabolic disorders (obesity and in animal models in response to emotional triggers (psychological stress, …. but the relationship between these modifications and the physiopathology of psychiatric disorders remains unclear. Recently, a large literature showed that this key metabolic/endocrine regulator is involved in stress and reward-oriented behaviors and regulates anxiety and mood. In addition, preproghrelin is a complex prohormone but the roles of the other ghrelin-derived peptides, thought to act as functional ghrelin antagonists, are largely unknown. Altered ghrelin secretion and/or signaling in psychiatric diseases are thought to participate in altered appetite, hedonic response and reward. Whether this can contribute to the mechanism responsible for the development of the disease or can help to minimize some symptoms associated with these psychiatric disorders is discussed in the present review. We will thus describe 1 the biological actions of ghrelin and ghrelin-derived peptides on food and drugs reward, anxiety and depression, and the physiological consequences of ghrelin invalidation on these parameters, 2 how ghrelin and ghrelin-derived peptides are regulated in animal models of psychiatric diseases and in human psychiatric disorders in relation with the GH

  1. Hydroxamic acid derivatives as potent peptide deformylase inhibitors and antibacterial agents.

    Science.gov (United States)

    Apfel, C; Banner, D W; Bur, D; Dietz, M; Hirata, T; Hubschwerlen, C; Locher, H; Page, M G; Pirson, W; Rossé, G; Specklin, J L

    2000-06-15

    Low-molecular-weight beta-sulfonyl- and beta-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.

  2. A Tetrameric Peptide Derived from Bovine Lactoferricin Exhibits Specific Cytotoxic Effects against Oral Squamous-Cell Carcinoma Cell Lines.

    Science.gov (United States)

    Solarte, Víctor A; Rosas, Jaiver E; Rivera, Zuly J; Arango-Rodríguez, Martha L; García, Javier E; Vernot, Jean-Paul

    2015-01-01

    Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC) cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20-25)4, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90%) in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC.

  3. Constraining cyclic peptides to mimic protein structure motifs

    DEFF Research Database (Denmark)

    Hill, Timothy A.; Shepherd, Nicholas E.; Diness, Frederik

    2014-01-01

    peptides can have protein-like biological activities and potencies, enabling their uses as biological probes and leads to therapeutics, diagnostics and vaccines. This Review highlights examples of cyclic peptides that mimic three-dimensional structures of strand, turn or helical segments of peptides...... and proteins, and identifies some additional restraints incorporated into natural product cyclic peptides and synthetic macrocyclic pepti-domimetics that refine peptide structure and confer biological properties....

  4. The Cysteine S-Alkylation Reaction as a Synthetic Method to Covalently Modify Peptide Sequences.

    Science.gov (United States)

    Calce, Enrica; De Luca, Stefania

    2017-01-05

    Synthetic methodologies to chemically modify peptide molecules have long been investigated for their impact in the field of chemical biology. They allow the introduction of biochemical probes useful for studying protein functions, for manipulating peptides with therapeutic potential, and for structure-activity relationship investigations. The commonly used approach was the derivatization of an amino acid side chain. In this regard, the cysteine, for its unique reactivity, has been widely employed as the substrate for such modifications. Herein, we report on methodologies developed to modify the cysteine thiol group through the S-alkylation reaction. Some procedures perform the alkylation of cysteine derivatives, in order to prepare building blocks to be used during the peptide synthesis, whilst some others selectively modify peptide sequences containing a cysteine residue with a free thiol group, both in solution and in the solid phase. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Design of mitochondria-targeted colorimetric and ratiometric fluorescent probes for rapid detection of SO2 derivatives in living cells

    Science.gov (United States)

    Yang, Yutao; Zhou, Tingting; Bai, Bozan; Yin, Caixia; Xu, Wenzhi; Li, Wei

    2018-05-01

    Two mitochondria-targeted colorimetric and ratiometric fluorescent probes for SO2 derivatives were constructed based on the SO2 derivatives-triggered Michael addition reaction. The probes exhibit high specificity toward HSO3-/SO32- by interrupting their conjugation system resulting in a large ratiometric blue shift of 46-121 nm in their emission spectrum. The two well-resolved emission bands can ensure accurate detection of HSO3-. The detection limits were calculated to be 1.09 and 1.35 μM. Importantly, probe 1 and probe 2 were successfully used to fluorescence ratiometric imaging of endogenous HSO3- in BT-474 cells.

  6. Amyloid fibril formation of peptides derived from the C-terminus of CETP modulated by lipids

    Energy Technology Data Exchange (ETDEWEB)

    García-González, Victor [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico); Mas-Oliva, Jaime, E-mail: jmas@ifc.unam.mx [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico); División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico)

    2013-04-26

    Highlights: •The secondary structure of a C-terminal peptide derived from CETP was studied. •Lipids modulate secondary structure changes of a C-terminal peptide derived from CETP. •Lysophosphatidic acid maintains a functional α-helix and prevents fibril formation. •Transfer of lipids by CETP is related to the presence of an α-helix at its C-end. -- Abstract: Cholesteryl-ester transfer protein (CETP) is a plasmatic protein involved in neutral lipid transfer between lipoproteins. Focusing on the last 12 C-terminus residues we have previously shown that mutation D{sub 470}N promotes a conformational change towards a β-secondary structure. In turn, this modification leads to the formation of oligomers and fibrillar structures, which cause cytotoxic effects similar to the ones provoked by amyloid peptides. In this study, we evaluated the role of specific lipid arrangements on the structure of peptide helix-Z (D{sub 470}N) through the use of thioflavin T fluorescence, peptide bond absorbance, circular dichroism and electron microscopy. The results indicate that the use of micelles formed with lysophosphatidylcholine and lysophosphatidic acid (LPA) under neutral pH induce a conformational transition of peptide helix-Z containing a β-sheet conformation to a native α-helix structure, therefore avoiding the formation of amyloid fibrils. In contrast, incubation with phosphatidic acid does not change the profile for the β-sheet conformation. When the electrostatic charge at the surface of micelles or vesicles is regulated through the use of lipids such as phospholipid and LPA, minimal changes and the presence of β-structures were recorded. Mixtures with a positive net charge diminished the percentage of β-structure and the amount of amyloid fibrils. Our results suggest that the degree of solvation determined by the presence of a free hydroxyl group on lipids such as LPA is a key condition that can modulate the secondary structure and the consequent formation of

  7. Amyloid fibril formation of peptides derived from the C-terminus of CETP modulated by lipids

    International Nuclear Information System (INIS)

    García-González, Victor; Mas-Oliva, Jaime

    2013-01-01

    Highlights: •The secondary structure of a C-terminal peptide derived from CETP was studied. •Lipids modulate secondary structure changes of a C-terminal peptide derived from CETP. •Lysophosphatidic acid maintains a functional α-helix and prevents fibril formation. •Transfer of lipids by CETP is related to the presence of an α-helix at its C-end. -- Abstract: Cholesteryl-ester transfer protein (CETP) is a plasmatic protein involved in neutral lipid transfer between lipoproteins. Focusing on the last 12 C-terminus residues we have previously shown that mutation D 470 N promotes a conformational change towards a β-secondary structure. In turn, this modification leads to the formation of oligomers and fibrillar structures, which cause cytotoxic effects similar to the ones provoked by amyloid peptides. In this study, we evaluated the role of specific lipid arrangements on the structure of peptide helix-Z (D 470 N) through the use of thioflavin T fluorescence, peptide bond absorbance, circular dichroism and electron microscopy. The results indicate that the use of micelles formed with lysophosphatidylcholine and lysophosphatidic acid (LPA) under neutral pH induce a conformational transition of peptide helix-Z containing a β-sheet conformation to a native α-helix structure, therefore avoiding the formation of amyloid fibrils. In contrast, incubation with phosphatidic acid does not change the profile for the β-sheet conformation. When the electrostatic charge at the surface of micelles or vesicles is regulated through the use of lipids such as phospholipid and LPA, minimal changes and the presence of β-structures were recorded. Mixtures with a positive net charge diminished the percentage of β-structure and the amount of amyloid fibrils. Our results suggest that the degree of solvation determined by the presence of a free hydroxyl group on lipids such as LPA is a key condition that can modulate the secondary structure and the consequent formation of amyloid

  8. A biomimetic collagen derived peptide exhibits anti-angiogenic activity in triple negative breast cancer.

    Directory of Open Access Journals (Sweden)

    Elena V Rosca

    Full Text Available We investigated the application of a mimetic 20 amino acid peptide derived from type IV collagen for treatment of breast cancer. We showed that the peptide induced a decrease of proliferation, adhesion, and migration of endothelial and tumor cells in vitro. We also observed an inhibition of triple negative MDA-MB-231 xenograft growth by 75% relative to control when administered intraperitoneally for 27 days at 10 mg/kg. We monitored in vivo the changes in vascular properties throughout the treatment using MRI and found that the vascular volume and permeability surface area product decreased significantly. The treatment also resulted in an increase of caspase-3 activity and in a reduction of microvascular density. The multiple mode of action of this peptide, i.e., anti-angiogenic, and anti-tumorigenic, makes it a viable candidate as a therapeutic agent as a monotherapy or in combination with other compounds.

  9. A novel acidic pH fluorescent probe based on a benzothiazole derivative

    Science.gov (United States)

    Ma, Qiujuan; Li, Xian; Feng, Suxiang; Liang, Beibei; Zhou, Tiqiang; Xu, Min; Ma, Zhuoyi

    2017-04-01

    A novel acidic pH fluorescent probe 1 based on a benzothiazole derivative has been designed, synthesized and developed. The linear response range covers the acidic pH range from 3.44 to 6.46, which is valuable for pH researches in acidic environment. The evaluated pKa value of the probe 1 is 4.23. The fluorescence enhancement of the studied probe 1 with an increase in hydrogen ions concentration is based on the hindering of enhanced photo-induced electron transfer (PET) process. Moreover, the pH sensor possesses a highly selective response to H+ in the presence of metal ions, anions and other bioactive small molecules which would be interfere with its fluorescent pH response. Furthermore, the probe 1 responds to acidic pH with short response time that was less than 1 min. The probe 1 has been successfully applied to confocal fluorescence imaging in live HeLa cells and can selectively stain lysosomes. All of such good properties prove it can be used to monitoring pH fluctuations in acidic environment with high sensitivity, pH dependence and short response time.

  10. Antibacterial activity in bovine lactoferrin-derived peptides.

    Science.gov (United States)

    Hoek, K S; Milne, J M; Grieve, P A; Dionysius, D A; Smith, R

    1997-01-01

    Several peptides sharing high sequence homology with lactoferricin B (Lf-cin B) were generated from bovine lactoferrin (Lf) with recombinant chymosin. Two peptides were copurified, one identical to Lf-cin B and another differing from Lf-cin B by the inclusion of a C-terminal alanine (lactoferricin). Two other peptides were copurified from chymosin-hydrolyzed Lf, one differing from Lf-cin B by the inclusion of C-terminal alanyl-leucine and the other being a heterodimer linked by a disulfide bond. These peptides were isolated in a single step from chymosin-hydrolyzed Lf by membrane ion-exchange chromatography and were purified by reverse-phase high-pressure liquid chromatography (HPLC). They were characterized by N-terminal Edman sequencing, mass spectrometry, and antibacterial activity determination. Pure lactoferricin, prepared from pepsin-hydrolyzed Lf, was purified by standard chromatography techniques. This peptide was analyzed against a number of gram-positive and gram-negative bacteria before and after reduction of its disulfide bond or cleavage after its single methionine residue and was found to inhibit the growth of all the test bacteria at a concentration of 8 microM or less. Subfragments of lactoferricin were isolated from reduced and cleaved peptide by reverse-phase HPLC. Subfragment 1 (residues 1 to 10) was active against most of the test microorganisms at concentrations of 10 to 50 microM. Subfragment 2 (residues 11 to 26) was active against only a few microorganisms at concentrations up to 100 microM. These antibacterial studies indicate that the activity of lactoferricin is mainly, but not wholly, due to its N-terminal region. PMID:8980754

  11. AWRK6, A Synthetic Cationic Peptide Derived from Antimicrobial Peptide Dybowskin-2CDYa, Inhibits Lipopolysaccharide-Induced Inflammatory Response

    Directory of Open Access Journals (Sweden)

    Qiuyu Wang

    2018-02-01

    Full Text Available Lipopolysaccharides (LPS are major outer membrane components of Gram-negative bacteria and produce strong inflammatory responses in animals. Most antibiotics have shown little clinical anti-endotoxin activity while some antimicrobial peptides have proved to be effective in blocking LPS. Here, the anti-LPS activity of the synthetic peptide AWRK6, which is derived from antimicrobial peptide dybowskin-2CDYa, has been investigated in vitro and in vivo. The positively charged α-helical AWRK6 was found to be effective in blocking the binding of LBP (LPS binding protein with LPS in vitro using ELISA. In a murine endotoxemia model, AWRK6 offered satisfactory protection efficiency against endotoxemia death, and the serum levels of LPS, IL-1β, IL-6, and TNF-α were found to be attenuated using ELISA. Further, histopathological analysis suggested that AWRK6 could improve the healing of liver and lung injury in endotoxemia mice. The results of real-time PCR and Western blotting showed that AWRK6 significantly reversed LPS-induced TLR4 overexpression and IκB depression, as well as the enhanced IκB phosphorylation. Additionally, AWRK6 did not produce any significant toxicity in vivo and in vitro. In summary, AWRK6 showed efficacious protection from LPS challenges in vivo and in vitro, by blocking LPS binding to LBP, without obvious toxicity, providing a promising strategy against LPS-induced inflammatory responses.

  12. A cyclic peptide derived from alpha-fetoprotein inhibits the proliferative effects of the epidermal growth factor and estradiol in MCF7 cells.

    Science.gov (United States)

    Torres, Cristian; Antileo, Elmer; Epuñán, Maráa José; Pino, Ana María; Valladares, Luis Emilio; Sierralta, Walter Daniel

    2008-06-01

    A cyclic peptide derived from the active domain of alpha-fetoprotein (AFP) significantly inhibited the proliferation of MCF7 cells stimulated with the epidermal growth factor (EGF) or estradiol (E2). The action of these three agents on cell growth was independent of the presence of calf serum in the culture medium. Our results demonstrated that the cyclic peptide interfered markedly with the regulation of MAPK by activated c-erbB2. The cyclic peptide showed no effect on the E2-stimulated release of matrix metalloproteinases 2 and 9 nor on the shedding of heparin-binding EGF into the culture medium. We propose that the AFP-derived cyclic peptide represents a valuable novel antiproliferative agent for treating breast cancer.

  13. γ-Preprotachykinin-(72-92)-peptide amide: An endogenous preprotachykinin I gene-derived peptide that preferentially binds to neurokinin-2 receptors

    International Nuclear Information System (INIS)

    Dam, T.V.; Takeda, Y.; Krause, J.E.; Escher, E.; Quirion, R.

    1990-01-01

    The presence of N-terminally extended forms of neurokinin A has recently been reported in the mammalian brain. Among them, gamma-preprotachykinin-(72-92)-peptide amide [gamma-PPT-(72-92)-NH2], a peptide derived by posttranslational processing of gamma-preprotachykinin, is most prominent. We report here that this peptide most likely acts on neurokinin-2 receptor sites since neurokinin A (a putative neurokinin-2 agonist) and gamma-PPT-(72-92)-NH2 are potent competitors of 125I-labeled gamma-PPT-(72-92)-NH2 binding whereas selective neurokinin-1 and -3 agonists are not. Moreover, the distribution of 125I-labeled gamma-PPT-(72-92)-NH2 and 125I-labeled neurokinin A binding sites are very similar in rat brain. On the other hand, 125I-labeled Bolton-Hunter-substance P (a neurokinin-1 ligand) and 125I-labeled Bolton-Hunter-eledoisin (a neurokinin-3 ligand) binding sites are differentially located in this tissue. Thus, it appears that gamma-PPT-(72-92)-NH2 binds to neurokinin-2 receptors and should be considered as a putative endogenous ligand for this receptor class

  14. Synthesis and evaluation of a radioiodinated peptide probe targeting αvβ6 integrin for the detection of pancreatic ductal adenocarcinoma

    International Nuclear Information System (INIS)

    Ueda, Masashi; Fukushima, Takahiro; Ogawa, Kei; Kimura, Hiroyuki; Ono, Masahiro; Yamaguchi, Takashi; Ikehara, Yuzuru; Saji, Hideo

    2014-01-01

    Highlights: • We developed a radioiodinated peptide probe targeting αvβ6 integrin ( 123 I-IFMDV2). • 123 I-IFMDV2 had a high affinity and selectivity for αvβ6 integrin. • 123 I-IFMDV2 showed a specific binding to αvβ6 integrin in vivo. • 123 I-IFMDV2 enabled clear visualization of the αvβ6-integrin-positive tumor. - Abstract: Introduction: Pancreatic ductal adenocarcinoma (PDAC) remains a major cause of cancer-related death. Since significant upregulation of αvβ6 integrin has been reported in PDAC, this integrin is a promising target for PDAC detection. In this study, we aimed to develop a radioiodinated probe for the imaging of αvβ6 integrin-positive PDAC with single-photon emission computed tomography (SPECT). Methods: Four peptide probes were synthesized and screened by competitive and saturation binding assays using 2 PDAC cell lines (AsPC-1, αvβ6 integrin-positive; MIA PaCa-2, αvβ6 integrin-negative). The probe showing the best affinity was used to study the biodistribution assay, an in vivo blocking study, and SPECT imaging using tumor bearing mice. Autoradiography and immunohistochemical analysis were also performed. Results: Among the 4 probes examined in this study, 125 I-IFMDV2 showed the highest affinity for αvβ6 integrin expressed in AsPC-1 cells and no affinity for MIA PaCa-2 cells. The accumulation of 125 I-IFMDV2 in the AsPC-1 xenograft was 3–5 times greater than that in the MIA PaCa-2 xenograft, consistent with the expression of αvβ6 integrin in each xenograft, and confirmed by immunohistochemistry. Pretreatment with excess amounts of A20FMDV2 significantly blocked the accumulation of 125 I-IFMDV2 in the AsPC-1 xenograft, but not in the MIA PaCa-2 xenograft. Furthermore, 123 I-IFMDV2 enabled clear visualization of the AsPC-1 xenograft. Conclusion: 123 I-IFMDV2 is a potential SPECT probe for the imaging of αvβ6 integrin in PDAC

  15. 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, ...

  16. Recombinant phage probes for Listeria monocytogenes

    Science.gov (United States)

    Carnazza, S.; Gioffrè, G.; Felici, F.; Guglielmino, S.

    2007-10-01

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 104 cells ml-1. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  17. A Tetrameric Peptide Derived from Bovine Lactoferricin Exhibits Specific Cytotoxic Effects against Oral Squamous-Cell Carcinoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Víctor A. Solarte

    2015-01-01

    Full Text Available Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20–254, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90% in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC.

  18. Human Platelet-Rich Plasma- and Extracellular Matrix-Derived Peptides Promote Impaired Cutaneous Wound Healing In Vivo

    Science.gov (United States)

    Demidova-Rice, Tatiana N.; Wolf, Lindsey; Deckenback, Jeffry; Hamblin, Michael R.; Herman, Ira M.

    2012-01-01

    Previous work in our laboratory has described several pro-angiogenic short peptides derived from endothelial extracellular matrices degraded by bacterial collagenase. Here we tested whether these peptides could stimulate wound healing in vivo. Our experiments demonstrated that a peptide created as combination of fragments of tenascin X and fibrillin 1 (comb1) applied into cranial dermal wounds created in mice treated with cyclophosphamide to impair wound healing, can improve the rate of wound closure. Furthermore, we identify and characterize a novel peptide (UN3) created and modified from two naturally-occurring peptides, which are present in human platelet-rich plasma. In vitro testing of UN3 demonstrates that it causes a 50% increase in endothelial proliferation, 250% increase in angiogenic response and a tripling of epithelial cell migration in response to injury. Results of in vivo experiments where comb1 and UN3 peptides were added together to cranial wounds in cyclophosphamide-treated mice leads to improvement of wound vascularization as shown by an increase of the number of blood vessels present in the wound beds. Application of the peptides markedly promotes cellular responses to injury and essentially restores wound healing dynamics to those of normal, acute wounds in the absence of cyclophosphamide impairment. Our current work is aimed at understanding the mechanisms underlying the stimulatory effects of these peptides as well as identification of the cellular receptors mediating these effects. PMID:22384158

  19. 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.

  20. Synthesis, Characterization, and Initial Biological Evaluation of [99m Tc]Tc-Tricarbonyl-labeled DPA-α-MSH Peptide Derivatives for Potential Melanoma Imaging.

    Science.gov (United States)

    Gao, Feng; Sihver, Wiebke; Bergmann, Ralf; Belter, Birgit; Bolzati, Cristina; Salvarese, Nicola; Steinbach, Jörg; Pietzsch, Jens; Pietzsch, Hans-Jürgen

    2018-06-06

    α-Melanocyte stimulating hormone (α-MSH) derivatives target the melanocortin-1 receptor (MC1R) specifically and selectively. In this study, the α-MSH-derived peptide NAP-NS1 (Nle-Asp-His-d-Phe-Arg-Trp-Gly-NH 2 ) with and without linkers was conjugated with 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid (DPA-COOH) and labeled with [ 99m Tc]Tc-tricarbonyl by two methods. With the one-pot method the labeling was faster than with the two-pot method, while obtaining similarly high yields. Negligible trans-chelation and high stability in physiological solutions was determined for the [ 99m Tc]Tc-tricarbonyl-peptide conjugates. Coupling an ethylene glycol (EG)-based linker increased the hydrophilicity. The peptide derivatives displayed high binding affinity in murine B16F10 melanoma cells as well as in human MeWo and TXM13 melanoma cell homogenates. Preliminary in vivo studies with one of the [ 99m Tc]Tc-tricarbonyl-peptide conjugates showed good stability in blood and both renal and hepatobiliary excretion. Biodistribution was performed on healthy rats to gain initial insight into the potential relevance of the 99m Tc-labeled peptides for in vivo imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Milk-derived proteins and peptides in clinical trials

    Directory of Open Access Journals (Sweden)

    Jolanta Artym

    2013-08-01

    Full Text Available Clinical trials are reviewed, involving proteins and peptides derived from milk (predominantly bovine, with the exception of lactoferrin, which will be the subject of another article. The most explored milk fraction is α-lactalbumin (LA, which is often applied with glycomacropeptide (GMP – a casein degradation product. These milk constituents are used in health-promoting infant and adult formulae as well as in a modified form (HAMLET to treat cancer. Lactoperoxidase (LCP is used as an additive to mouth hygiene products and as a salivary substitute. Casein derivatives are applied, in addition, in the dry mouth syndrome. On the other hand, casein hydrolysates, containing active tripeptides, found application in hypertension and in type 2 diabetes. Lysozyme is routinely used for food conservation and in pharmaceutical products. It was successfully used in premature infants with concomitant diseases to improve health parameters. When used as prophylaxis in patients with scheduled surgery, it significantly reduced the incidence of hepatitis resulting from blood transfusion. Lysozyme was also used in infected children as an antimicrobial agent showing synergistic effects in combination with different antibiotics. Proline-rich polypeptide (PRP was introduced to therapy of Alzheimer’s disease patients. The therapeutic value of PRP was proved in several clinical trials and supported by studies on its mechanism of action. Concentrated immunoglobulin preparations from colostrum and milk of hyperimmunized cows showed efficacy in prevention of infections by bacteria, viruses and protozoa. A nutrition formula with milk-derived TGF-β2 (Modulen IBD® found application in treatment of pediatric Crohn’s disease. In conclusion, the preparations containing milk-derived products are safe and effective measures in prevention and treatment of infections as well as autoimmune and neoplastic diseases.

  2. Antimelanoma CTL recognizes peptides derived from an ORF transcribed from the antisense strand of the 3′ untranslated region of TRIT1

    Directory of Open Access Journals (Sweden)

    Rolf K Swoboda

    2014-01-01

    Full Text Available Noncoding regions of the genome play an important role in tumorigenesis of cancer. Using expression cloning, we have identified a cytotoxic T lymphocyte (CTL–defined antigen that recognizes a protein sequence derived from an open reading frame transcribed from the reverse strand in the 3′ untranslated region of tRNA isopentenyltransferase 1 (TRIT1. A peptide derived from this open reading frame (ORF sequence and predicted to bind to HLA-B57, sensitized HLA-B57+ tumor cells to lysis by CTL793. The peptide also induced a CTL response in peripheral blood mononuclear cells (PBMC of patient 793 and in two other melanoma patients. The CTL lysed peptide-pulsed HLA-B57+ target cells and melanoma cells with endogenous antigen expression. The recognition of this antigen is not limited to HLA-B57-restricted CTLs. An HLA-A2 peptide derived from the ORF was able to induce CTLs in PBMC of 2 HLA-A2+ patients. This study describes for the first time a CTL-defined melanoma antigen that is derived from an ORF on the reverse strand of the putative tumor suppressor gene TRIT1. This antigen has potential use as a vaccine or its ability to induce CTLs in vitro could be used as a predictive biomarker.

  3. ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.

    Directory of Open Access Journals (Sweden)

    Jonathan H Wardman

    Full Text Available ProSAAS is the precursor for some of the most abundant peptides found in mouse brain and other tissues, including peptides named SAAS, PEN, and LEN. Both SAAS and LEN are found in big and little forms due to differential processing. Initial processing of proSAAS is mediated by furin (and/or furin-like enzymes and carboxypeptidase D, while the smaller forms are generated by secretory granule prohormone convertases and carboxypeptidase E. In mouse hypothalamus, PEN and big LEN colocalize with neuropeptide Y. In the present study, little LEN and SAAS were detected in mouse hypothalamus but not in cell bodies of neuropeptide Y-expressing neurons. PEN and big LEN show substantial colocalization in hypothalamus, but big LEN and little LEN do not. An antiserum to SAAS that detects both big and little forms of this peptide did not show substantial colocalization with PEN or big LEN. To further study this, the AtT-20 cells mouse pituitary corticotrophic cell line was transfected with rat proSAAS and the distribution of peptides examined. As found in mouse hypothalamus, only some of the proSAAS-derived peptides colocalized with each other in AtT-20 cells. The two sites within proSAAS that are known to be efficiently cleaved by furin were altered by site-directed mutagenesis to convert the P4 Arg into Lys; this change converts the sequences from furin consensus sites into prohormone convertase consensus sites. Upon expression of the mutated form of proSAAS in AtT-20 cells, there was significantly more colocalization of proSAAS-derived peptides PEN and SAAS. Taken together, these results indicate that proSAAS is initially cleaved in the Golgi or trans-Golgi network by furin and/or furin-like enzymes and the resulting fragments are sorted into distinct vesicles and further processed by additional enzymes into the mature peptides.

  4. Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076.

    Science.gov (United States)

    Huertas Méndez, Nataly De Jesús; Vargas Casanova, Yerly; Gómez Chimbi, Anyelith Katherine; Hernández, Edith; Leal Castro, Aura Lucia; Melo Diaz, Javier Mauricio; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo

    2017-03-12

    Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli .

  5. NMR spectroscopic studies of a TAT-derived model peptide in imidazolium-based ILs: influence on chemical shifts and the cis/trans equilibrium state.

    Science.gov (United States)

    Wiedemann, Christoph; Ohlenschläger, Oliver; Mrestani-Klaus, Carmen; Bordusa, Frank

    2017-09-13

    NMR spectroscopy was used to study systematically the impact of imidazolium-based ionic liquid (IL) solutions on a TAT-derived model peptide containing Xaa-Pro peptide bonds. The selected IL anions cover a wide range of the Hofmeister series of ions. Based on highly resolved one- and two-dimensional NMR spectra individual 1 H and 13 C peptide chemical shift differences were analysed and a classification of IL anions according to the Hofmeister series was derived. The observed chemical shift changes indicate significant interactions between the peptide and the ILs. In addition, we examined the impact of different ILs towards the cis/trans equilibrium state of the Xaa-Pro peptide bonds. In this context, the IL cations appear to be of exceptional importance for inducing an alteration of the native cis/trans equilibrium state of Xaa-Pro bonds in favour of the trans-isomers.

  6. Structure of a SARS coronavirus-derived peptide bound to the human major histocompatibility complex class I molecule HLA-B*1501

    DEFF Research Database (Denmark)

    Røder, Gustav; Kristensen, Ole; Kastrup, Jette S

    2008-01-01

    , the crystal structure of HLA-B*1501 in complex with a SARS coronavirus-derived nonapeptide (VQQESSFVM) has been determined at high resolution (1.87 A). The peptide is deeply anchored in the B and F pockets, but with the Glu4 residue pointing away from the floor in the peptide-binding groove, making...

  7. Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides.

    Science.gov (United States)

    Tasiemski, Aurélie; Hammad, Hamida; Vandenbulcke, Franck; Breton, Christophe; Bilfinger, Thomas J; Pestel, Joel; Salzet, Michel

    2002-07-15

    Chromogranin A (CGA) and chromogranin B (CGB) are acidic proteins stored in secretory organelles of endocrine cells and neurons. In addition to their roles as helper proteins in the packaging of peptides, they may serve as prohormones to generate biologically active peptides such as vasostatin-1 and secretolytin. These molecules derived from CGA and CGB, respectively, possess antimicrobial properties. The present study demonstrates that plasmatic levels of both vasostatin-1 and secretolytin increase during surgery in patients undergoing cardiopulmonary bypass (CPB). Vasostatin-1 and secretolytin, initially present in plasma at low levels, are released just after skin incision. Consequently, they can be added to enkelytin, an antibacterial peptide derived from proenkephalin A, for the panoply of components acting as a first protective barrier against hypothetical invasion of pathogens, which may occur during surgery. CGA and CGB, more commonly viewed as markers for endocrine and neuronal cells, were also found to have an immune origin. RNA messengers coding for CGB were amplified by reverse transcription-polymerase chain reaction in human monocytes, and immunocytochemical analysis by confocal microscopy revealed the presence of CGA or CGB or both in monocytes and neutrophils. A combination of techniques including confocal microscopic analysis, mass spectrometry measurement, and antibacterial tests allowed for the identification of the positive role of interleukin 6 (IL-6) in the secretolytin release from monocytes in vitro. Because IL-6 release is known to be strongly enhanced during CPB, we suggest a possible relationship between IL-6 and the increased level of secretolytin in patients undergoing CPB.

  8. 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.

  9. 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

  10. Conformational analysis of Infectious bursal disease virus (IBDV derived cell penetrating peptide (CPP analogs

    Directory of Open Access Journals (Sweden)

    Vinay G. Joshi

    2013-12-01

    Full Text Available Aim: This study was designed to develop peptide analogs of Infectious Bursal Disease (IBD virus VP5 protein segment having cell penetrating ability to improve their interaction with cargo molecule (Nucleic acid without affecting the backbone conformation. Materials and Methods: IBDV VP5 protein segment designated as RATH peptide were synthesized using solid phase peptide synthesis and their solution conformation was elucidated using CD spectroscopy in polar (water and apolar (TFE solvents. Cell penetrating ability of RATH-CONH2 was observed using FITC labeled peptide internalization in to HeLa cells under fluorescent microscopy. The efficacy of RATH analog interactions with nucleic acids was evaluated using FITC labeled oligonucleotides by fluorescence spectroscopy and plasmid constructs in gel retardation assay. Results: CD spectra of RATH analogs in water and apolar trifluroethanol (TFE helped to compare their secondary structures which were almost similar with dominant beta conformations suggesting successful induction of positive charge in the analogs without affecting back bone conformation of CPP designed. Cell penetrating ability of RATH CONH2 in HeLa cell was more than 90%. The fluorescence spectroscopy and plasmid constructs in gel retardation assay demonstrated successful interaction of amide analogs with nucleic acid. Conclusion: Intentional changes made in IBDV derived peptide RATH COOH to RATH CONH2 did not showed major changes in backbone conformation and such modifications may help to improve the cationic charge in most CPPs to interact with nucleic acid. [Vet World 2013; 6(6.000: 307-312

  11. In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence

    Science.gov (United States)

    Figueira, T. N.; Palermo, L. M.; Veiga, A. S.; Huey, D.; Alabi, C. A.; Santos, N. C.; Welsch, J. C.; Mathieu, C.; Niewiesk, S.; Moscona, A.

    2016-01-01

    ABSTRACT Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo. We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides. IMPORTANCE Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides. PMID:27733647

  12. ProSAAS-derived peptides are regulated by cocaine and are required for sensitization to the locomotor effects of cocaine.

    Science.gov (United States)

    Berezniuk, Iryna; Rodriguiz, Ramona M; Zee, Michael L; Marcus, David J; Pintar, John; Morgan, Daniel J; Wetsel, William C; Fricker, Lloyd D

    2017-11-01

    To identify neuropeptides that are regulated by cocaine, we used a quantitative peptidomic technique to examine the relative levels of neuropeptides in several regions of mouse brain following daily intraperitoneal administration of 10 mg/kg cocaine or saline for 7 days. A total of 102 distinct peptides were identified in one or more of the following brain regions: nucleus accumbens, caudate putamen, frontal cortex, and ventral tegmental area. None of the peptides detected in the caudate putamen or frontal cortex were altered by cocaine administration. Three peptides in the nucleus accumbens and seven peptides in the ventral tegmental area were significantly decreased in cocaine-treated mice. Five of these ten peptides are derived from proSAAS, a secretory pathway protein and neuropeptide precursor. To investigate whether proSAAS peptides contribute to the physiological effects of psychostimulants, we examined acute responses to cocaine and amphetamine in the open field with wild-type (WT) and proSAAS knockout (KO) mice. Locomotion was stimulated more robustly in the WT compared to mutant mice for both psychostimulants. Behavioral sensitization to amphetamine was not maintained in proSAAS KO mice and these mutants failed to sensitize to cocaine. To determine whether the rewarding effects of cocaine were altered, mice were tested in conditioned place preference (CPP). Both WT and proSAAS KO mice showed dose-dependent CPP to cocaine that was not distinguished by genotype. Taken together, these results suggest that proSAAS-derived peptides contribute differentially to the behavioral sensitization to psychostimulants, while the rewarding effects of cocaine appear intact in mice lacking proSAAS. © 2017 International Society for Neurochemistry.

  13. Bodipy-VAD-Fmk, a useful tool to study yeast peptide N-glycanase activity

    NARCIS (Netherlands)

    Witte, Martin D.; Descals, Carlos V.; Lavoir, Sebastiaan V.P. de; Florea, Bogdan I.; Marel, Gijsbert A. van der; Overkleeft, Herman S.

    2007-01-01

    In this paper the development of a fluorescent activity based probe, Bodipy-VAD-Fmk, for visualization of yeast peptide N-glycanase is described. The activity based probe is used to assess the efficacy of known and new chitobiose-based electrophilic traps to bind yeast peptide N-glycanase.

  14. Investigation of SP94 Peptide as a Specific Probe for Hepatocellular Carcinoma Imaging and Therapy

    Science.gov (United States)

    Li, Yanli; Hu, Yan; Xiao, Jie; Liu, Guobing; Li, Xiao; Zhao, Yanzhao; Tan, Hui; Shi, Hongcheng; Cheng, Dengfeng

    2016-01-01

    SP94 (SFSIIHTPILPL), a novel peptide, has shown specific binding to hepatocellular carcinoma (HCC) cells. We aimed to investigate the capability of SP94 as a targeting probe for HCC imaging and therapy following labeling with technetium-99m (99mTc) and rhenium-188 (188Re). HYNIC-SP94 was prepared by solid phase synthesis and then labeled with 99mTc. Cell competitive binding, internalization assay, in vitro and in vivo stability, biodistribution and micro-single photon emission computed tomography /computed tomography (SPECT/CT) imaging studies were performed to investigate the capability of 99mTc tricine-EDDA/HYNIC-SP94 as a specific HCC imaging probe. Initial promising targeting results inspired evaluation of its therapeutic effect when labeled by 188Re. HYNIC-SP94 was then labeled again with 188Re to perform cell apoptosis, microSPECT/CT imaging evaluation and immunohistochemistry. Huh-7 cells exhibited typical apoptotic changes after 188Re irradiation. According to 99mTc tricine-EDDA/HYNIC-SP94 microSPECT/CT imaging, tumor uptake was significantly decreased compared with that of pre-treatment with 188Re-HYNIC-SP94. The immunohistochemistry also displayed obvious necrosis and apoptosis as well as inhibition of proliferation in the 188Re-HYNIC-SP94 treatment group. The results supported that 99mTc tricine-EDDA/HYNIC-SP94 is able to target HCC cells and 188Re-HYNIC- SP94 holds potential as a therapeutic agent for HCC, making 99mTc/188Re-HYNIC-SP94 a promising targeting probe for HCC imaging and therapy. PMID:27649935

  15. 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

  16. Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338.

    Science.gov (United States)

    Meyer, Sven W; Mordhorst, Thorsten F; Lee, Choonghwan; Jensen, Paul R; Fenical, William; Köck, Matthias

    2010-05-07

    A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments.

  17. Molecular basis for endotoxin neutralization by amphipathic peptides derived from the alpha-helical cationic core-region of NK-lysin.

    Science.gov (United States)

    Brandenburg, Klaus; Garidel, Patrick; Fukuoka, Satoshi; Howe, Jörg; Koch, Michel H J; Gutsmann, Thomas; Andrä, Jörg

    2010-08-01

    An analysis of the interaction of the NK-lysin derived peptide NK-2 and of analogs thereof with bacterial lipopolysaccharide (LPS, endotoxin) was performed to determine the most important biophysical parameters for an effective LPS neutralization. We used microcalorimetry, FTIR spectroscopy, Zeta potential measurements, and small-angle X-ray scattering to analyze the peptide:LPS binding enthalpy, the accessible LPS surface charge, the fluidity of the LPS hydrocarbon chains, their phase transition enthalpy change, the aggregate structure of LPS, and how these parameters are modulated by the peptides. We conclude that (i) a high peptide:LPS binding affinity, which is facilitated by electrostatic and hydrophobic interactions and which leads to a positive Zeta potential, (ii) the formation of peptide-enriched domains, which destabilize the lipid packing, demonstrated by a drastic decrease of phase transition enthalpy change of LPS, and (iii) the multilamellarization of the LPS aggregate structure are crucial for an effective endotoxin neutralization by cationic peptides.

  18. Recombinant phage probes for Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S; Gioffre, G; Felici, F; Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2007-10-03

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 10{sup 4} cells ml{sup -1}. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  19. Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076

    Directory of Open Access Journals (Sweden)

    Nataly De Jesús Huertas Méndez

    2017-03-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B–containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli.

  20. Chemical probing of the human sirtuin 5 active site reveals its substrate acyl specificity and peptide-based inhibitors.

    Science.gov (United States)

    Roessler, Claudia; Nowak, Theresa; Pannek, Martin; Gertz, Melanie; Nguyen, Giang T T; Scharfe, Michael; Born, Ilona; Sippl, Wolfgang; Steegborn, Clemens; Schutkowski, Mike

    2014-09-26

    Sirtuins are NAD(+)-dependent deacetylases acting as sensors in metabolic pathways and stress response. In mammals there are seven isoforms. The mitochondrial sirtuin 5 is a weak deacetylase but a very efficient demalonylase and desuccinylase; however, its substrate acyl specificity has not been systematically analyzed. Herein, we investigated a carbamoyl phosphate synthetase 1 derived peptide substrate and modified the lysine side chain systematically to determine the acyl specificity of Sirt5. From that point we designed six potent peptide-based inhibitors that interact with the NAD(+) binding pocket. To characterize the interaction details causing the different substrate and inhibition properties we report several X-ray crystal structures of Sirt5 complexed with these peptides. Our results reveal the Sirt5 acyl selectivity and its molecular basis and enable the design of inhibitors for Sirt5. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Martinez-Becerra, Francisco; Silva, Daniel-Adriano; Dominguez-Ramirez, Lenin; Mendoza-Hernandez, Guillermo; Lopez-Vidal, Yolanda; Soldevila, Gloria; Garcia-Zepeda, Eduardo A.

    2007-01-01

    Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in α helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa

  2. Analysis and Evaluation of the Inhibitory Mechanism of a Novel Angiotensin-I-Converting Enzyme Inhibitory Peptide Derived from Casein Hydrolysate.

    Science.gov (United States)

    Tu, Maolin; Liu, Hanxiong; Zhang, Ruyi; Chen, Hui; Mao, Fengjiao; Cheng, Shuzhen; Lu, Weihong; Du, Ming

    2018-04-25

    Casein hydrolysates exert various biological activities, and the responsible functional peptides are being identified from them continuously. In this study, the tryptic casein hydrolysate was fractionated by an ultrafiltration membrane (3 kDa), and the peptides were identified by capillary electrophoresis-quadrupole-time-of-flight-tandem mass spectrometry. Meanwhile, in silico methods were used to analyze the toxicity, solubility, stability, and affinity between the peptides and angiotensin-I-converting enzyme (ACE). Finally, a new angiotensin-I-converting enzyme inhibitory (ACEI) peptide, EKVNELSK, derived from α s1 -casein (fragment 35-42) was screened. The half maximal inhibitory concentration value of the peptide is 5.998 mM, which was determined by a high-performance liquid chromatography method. The Lineweaver-Burk plot indicated that this peptide is a mixed-type inhibitor against ACE. Moreover, Discovery Studio 2017 R2 software was adopted to perform molecular docking to propose the potential mechanisms underlying the ACEI activity of the peptide. These results indicated that EKVNELSK is a new ACEI peptide identified from casein hydrolysate.

  3. Cleavage specificity analysis of six type II transmembrane serine proteases (TTSPs using PICS with proteome-derived peptide libraries.

    Directory of Open Access Journals (Sweden)

    Olivier Barré

    Full Text Available Type II transmembrane serine proteases (TTSPs are a family of cell membrane tethered serine proteases with unclear roles as their cleavage site specificities and substrate degradomes have not been fully elucidated. Indeed just 52 cleavage sites are annotated in MEROPS, the database of proteases, their substrates and inhibitors.To profile the active site specificities of the TTSPs, we applied Proteomic Identification of protease Cleavage Sites (PICS. Human proteome-derived database searchable peptide libraries were assayed with six human TTSPs (matriptase, matriptase-2, matriptase-3, HAT, DESC and hepsin to simultaneously determine sequence preferences on the N-terminal non-prime (P and C-terminal prime (P' sides of the scissile bond. Prime-side cleavage products were isolated following biotinylation and identified by tandem mass spectrometry. The corresponding non-prime side sequences were derived from human proteome databases using bioinformatics. Sequencing of 2,405 individual cleaved peptides allowed for the development of the family consensus protease cleavage site specificity revealing a strong specificity for arginine in the P1 position and surprisingly a lysine in P1' position. TTSP cleavage between R↓K was confirmed using synthetic peptides. By parsing through known substrates and known structures of TTSP catalytic domains, and by modeling the remainder, structural explanations for this strong specificity were derived.Degradomics analysis of 2,405 cleavage sites revealed a similar and characteristic TTSP family specificity at the P1 and P1' positions for arginine and lysine in unfolded peptides. The prime side is important for cleavage specificity, thus making these proteases unusual within the tryptic-enzyme class that generally has overriding non-prime side specificity.

  4. Benzothiadiazole Derivatives as Fluorescence Imaging Probes: Beyond Classical Scaffolds.

    Science.gov (United States)

    Neto, Brenno A D; Carvalho, Pedro H P R; Correa, Jose R

    2015-06-16

    This Account describes the origins, features, importance, and trends of the use of fluorescent small-molecule 2,1,3-benzothiadiazole (BTD) derivatives as a new class of bioprobes applied to bioimaging analyses of several (live and fixed) cell types. BTDs have been successfully used as probes for a plethora of biological analyses for only a few years, and the impressive responses obtained by using this important class of heterocycle are fostering the development of new fluorescent BTDs and expanding the biological applications of such derivatives. The first use of a fluorescent small-molecule BTD derivative as a selective cellular probe dates back to 2010, and since then impressive advances have been described by us and others. The well-known limitations of classical scaffolds urged the development of new classes of bioprobes. Although great developments have been achieved by using classical scaffolds such as coumarins, BODIPYs, fluoresceins, rhodamines, cyanines, and phenoxazines, there is still much to be done, and BTDs aim to succeed where these dyes have shown their limitations. Important organelles and cell components such as nuclear DNA, mitochondria, lipid droplets, and others have already been successfully labeled by fluorescent small-molecule BTD derivatives. New technological systems that use BTDs as the fluorophores for bioimaging experiments have been described in recent scientific literature. The successful application of BTDs as selective bioprobes has led some groups to explore their potential for use in studying membrane pores or tumor cells under hypoxic conditions. Finally, BTDs have also been used as fluorescent tags to investigate the action mechanism of some antitumor compounds. The attractive photophysical data typically observed for π-extended BTD derivatives is fostering interest in the use of this new class of bioprobes. Large Stokes shifts, large molar extinction coefficients, high quantum yields, high stability when stored in solution or

  5. Structure–activity relationships of the human prothrombin kringle-2 peptide derivative NSA9: anti-proliferative activity and cellular internalization

    OpenAIRE

    Hwang, Hyun Sook; Kim, Dong Won; Kim, Soung Soo

    2006-01-01

    The human prothrombin kringle-2 protein inhibits angiogenesis and LLC (Lewis lung carcinoma) growth and metastasis in mice. Additionally, the NSA9 peptide (NSAVQLVEN) derived from human prothrombin kringle-2 has been reported to inhibit the proliferation of BCE (bovine capillary endothelial) cells and CAM (chorioallantoic membrane) angiogenesis. In the present study, we examined the structure–activity relationships of the NSA9 peptide in inhibiting the proliferation of endothelial cells lines...

  6. Ultramild protein-mediated click chemistry creates efficient oligonucleotide probes for targeting and detecting nucleic acids

    DEFF Research Database (Denmark)

    Nåbo, Lina J.; Madsen, Charlotte S.; Jensen, Knud J.

    2015-01-01

    Functionalized synthetic oligonucleotides are finding growing applications in research, clinical studies, and therapy. However, it is not easy to prepare them in a biocompatible and highly efficient manner. We report a new strategy to synthesize oligonucleotides with promising nucleic acid...... targeting and detection properties. We focus in particular on the pH sensitivity of these new probes and their high target specificity. For the first time, human copper(I)-binding chaperon Cox17 was applied to effectively catalyze click labeling of oligonucleotides. This was performed under ultramild...... conditions with fluorophore, peptide, and carbohydrate azide derivatives. In thermal denaturation studies, the modified probes showed specific binding to complementary DNA and RNA targets. Finally, we demonstrated the pH sensitivity of the new rhodamine-based fluorescent probes in vitro and rationalize our...

  7. Electrochemistry of a ferrocene-grafted cell-penetrating peptide

    International Nuclear Information System (INIS)

    Messina, Pierluca; Hallais, Géraldine; Labbé, Eric; Béranger, Marie; Chassaing, Gérard; Lavielle, Solange; Mansuy, Christelle; Buriez, Olivier

    2012-01-01

    A cationic cell-penetrating peptide (CPP) labeled with both a ferrocenyl (Fc) moiety and a biotin (B) was successfully synthesized and investigated by electrochemistry. This original CPP derivative noted as Fc-CPP-B could be electrochemically detected, at a micromolar concentration, at a naked gold bead electrode. The presence of a biotin tag in the Fc-CPP-B complex allowed its complexation with avidin, which was itself tethered to a thiolated self-assembled monolayer. Such an avidin-modified gold surface, characterized by atomic force microscopy (AFM), allowed the immobilization of Fc-CPP-B onto the electrode surface, which greatly enhanced its electrochemical detection. Nevertheless, under these conditions the electrogenerated ferrocenium cation could not be reduced during the backward scan, indicating its unexpected reactivity when tethered within the avidin environment. In terms of detection and redox probe regeneration the best results were obtained at a glassy carbon electrode modified with a cation-exchange polymer. Ion-exchange voltammetry, performed under these conditions, allowed the pre-concentration of the peptide at the electrode surface thanks to the net positive charge of the CPP derivative. Interestingly, the anionic character of the polymer contributed to retain the electrogenerated cation Fc + in the film so that it could be reduced back to its original neutral form during the reverse voltammetric scans.

  8. Isolated Gramicidin Peptides Probed by IR Spectroscopy

    NARCIS (Netherlands)

    Rijs, A. M.; Kabelac, M.; Abo-Riziq, A.; Hobza, P.; de Vries, M. S.

    2011-01-01

    We report double-resonant IR/UV ion-dip spectroscopy of neutral gramicidin peptides in the gas phase. The IR spectra of gramicidin A and C, recorded in both the 1000 cm(-1) to 1800 cm(-1) and the 2700 to 3750 cm(-1) region, allow structural analysis. By studying this broad IR range, various local

  9. 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.

  10. Controlled Retention of BMP-2-Derived Peptide on Nanofibers Based on Mussel-Inspired Adhesion for Bone Formation.

    Science.gov (United States)

    Lee, Jinkyu; Perikamana, Sajeesh Kumar Madhurakkat; Ahmad, Taufiq; Lee, Min Suk; Yang, Hee Seok; Kim, Do-Gyoon; Kim, Kyobum; Kwon, Bosun; Shin, Heungsoo

    2017-04-01

    Although bone morphogenetic protein-2 (BMP-2) has been frequently used to stimulate bone formation, it has several side effects to be addressed, including the difficulty in optimization of clinically relevant doses and unwanted induction of cancerous signaling processes. In this study, an osteogenic peptide (OP) derived from BMP-2 was investigated as a substitute for BMP-2. In vitro studies showed that OP was able to enhance the osteogenic differentiation and mineralization of human mesenchymal stem cells (hMSCs). The peptides were then conjugated onto biocompatible poly-ι-lactide electrospun nanofibers through polydopamine chemistry. Surface chemical analysis proved that more than 80% of the peptides were stably retained on the nanofiber surface after 8 h of polydopamine coating during at least 28 days, and the amount of peptides that was retained increased depending on the polydopamine coating time. For instance, about 65% of the peptides were retained on nanofibers after 4 h of polydopamine coating. Also, a relatively small dose of peptides could effectively induce bone formation in in vivo critical-sized defects on the calvarial bones of mice. More than 50.4% ± 16.9% of newly formed bone was filled within the defect after treatment with only 10.5 ± 0.6 μg of peptides. Moreover, these groups had similar elastic moduli and contact hardnesses with host bone. Taken together, our results suggest that polydopamine-mediated OP immobilized on nanofibers can modulate the retention of relatively short lengths of peptides, which might make this an effective therapeutic remedy to guide bone regeneration using a relatively small amount of peptides.

  11. Bis-pyridinium quadrupolar derivatives. High Stokes shift selective probes for bio-imaging

    Science.gov (United States)

    Salice, Patrizio; Versari, Silvia; Bradamante, Silvia; Meinardi, Francesco; Macchi, Giorgio; Pagani, Giorgio A.; Beverina, Luca

    2013-11-01

    We describe the design, synthesis and characterization of five high Stokes shift quadrupolar heteroaryl compounds suitable as fluorescent probes in bio-imaging. In particular, we characterize the photophysical properties and the intracellular localization in Human Umbilical Vein Endothelial Cells (HUVEC) and Human Mesenchymal Stem Cells (HMSCs) for each dye. We show that, amongst all of the investigated derivatives, the 2,5-bis[1-(4-N-methylpyridinium)ethen-2-yl)]- N-methylpyrrole salt is the best candidates as selective mitochondrial tracker. Finally, we recorded the full emission spectrum of the most performing - exclusively mitochondrial selective - fluorescent probe directly from HUVEC stained cells. The emission spectrum collected from the stained mitochondria shows a remarkably more pronounced vibronic structure with respect to the emission of the free fluorophore in solution.

  12. Design and evaluation of antimalarial peptides derived from prediction of short linear motifs in proteins related to erythrocyte invasion.

    Directory of Open Access Journals (Sweden)

    Alessandra Bianchin

    Full Text Available The purpose of this study was to investigate the blood stage of the malaria causing parasite, Plasmodium falciparum, to predict potential protein interactions between the parasite merozoite and the host erythrocyte and design peptides that could interrupt these predicted interactions. We screened the P. falciparum and human proteomes for computationally predicted short linear motifs (SLiMs in cytoplasmic portions of transmembrane proteins that could play roles in the invasion of the erythrocyte by the merozoite, an essential step in malarial pathogenesis. We tested thirteen peptides predicted to contain SLiMs, twelve of them palmitoylated to enhance membrane targeting, and found three that blocked parasite growth in culture by inhibiting the initiation of new infections in erythrocytes. Scrambled peptides for two of the most promising peptides suggested that their activity may be reflective of amino acid properties, in particular, positive charge. However, one peptide showed effects which were stronger than those of scrambled peptides. This was derived from human red blood cell glycophorin-B. We concluded that proteome-wide computational screening of the intracellular regions of both host and pathogen adhesion proteins provides potential lead peptides for the development of anti-malarial compounds.

  13. Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Berbís, M. Álvaro [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); André, Sabine [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Cañada, F. Javier [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); Pipkorn, Rüdiger [Central Peptide Synthesis Unit, German Cancer Research Center, 69120 Heidelberg (Germany); Ippel, Hans [Department of Biochemistry, CARIM, University of Maastricht, Maastricht (Netherlands); Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Mayo, Kevin H. [Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Kübler, Dieter [Biomolecular Interactions, German Cancer Research Center, 69120 Heidelberg (Germany); Gabius, Hans-Joachim [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Jiménez-Barbero, Jesús, E-mail: jjbarbero@cib.csic.es [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain)

    2014-01-03

    Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with {sup 15}N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein.

  14. Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

    International Nuclear Information System (INIS)

    Berbís, M. Álvaro; André, Sabine; Cañada, F. Javier; Pipkorn, Rüdiger; Ippel, Hans; Mayo, Kevin H.; Kübler, Dieter; Gabius, Hans-Joachim; Jiménez-Barbero, Jesús

    2014-01-01

    Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with 15 N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein

  15. Peptide vaccination against multiple myeloma using peptides derived from anti-apoptotic protein

    DEFF Research Database (Denmark)

    Jørgensen, Nicolai Grønne Dahlager; Ahmad, Shamaila Munir; Abildgaard, N.

    2016-01-01

    The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic vacc...... vaccination. Vaccination against Bcl-2 was well tolerated and was able to induce immune responses in patients with relapsed MM. © Stem Cell Investigation. All rights reserved.......The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic...... vaccination with peptides from the proteins Bcl-2, Bcl-XL and Mcl-1 in patients with relapsed MM. Vaccines were given concomitant with bortezomib. Out of 7 enrolled patients, 4 received the full course of 8 vaccinations. The remaining 3 patients received fewer vaccinations due to progression, clinical...

  16. A new fluorescence/PET probe for targeting intracellular human telomerase reverse transcriptase (hTERT) using Tat peptide-conjugated IgM

    International Nuclear Information System (INIS)

    Jung, Kyung oh; Youn, Hyewon; Kim, Seung Hoo; Kim, Young-Hwa; Kang, Keon Wook; Chung, June-Key

    2016-01-01

    Despite an increasing need for methods to visualize intracellular proteins in vivo, the majority of antibody-based imaging methods available can only detect membrane proteins. The human telomerase reverse transcriptase (hTERT) is an intracellular target of great interest because of its high expression in several types of cancer. In this study, we developed a new probe for hTERT using the Tat peptide. An hTERT antibody (IgG or IgM) was conjugated with the Tat peptide, a fluorescence dye and "6"4Cu. HT29 (hTERT+) and U2OS (hTERT−) were used to visualize the intracellular hTERT. The hTERT was detected by RT-PCR and western blot. Fluorescence signals for hTERT were obtained by confocal microscopy, live cell imaging, and analyzed by Tissue-FAXS. In nude mice, tumors were visualized using the fluorescence imaging devices Maestro™ and PETBOX. In RT-PCR and western blot, the expression of hTERT was detected in HT29 cells, but not in U2OS cells. Fluorescence signals were clearly observed in HT29 cells and in U2OS cells after 1 h of treatment, but signals were only detected in HT29 cells after 24 h. Confocal microscopy showed that 9.65% of U2OS and 78.54% of HT29 cells had positive hTERT signals. 3D animation images showed that the probe could target intranuclear hTERT in the nucleus. In mice models, fluorescence and PET imaging showed that hTERT in HT29 tumors could be efficiently visualized. In summary, we developed a new method to visualize intracellular and intranuclear proteins both in vitro and in vivo. - Highlights: • We developed new probes for imaging hTERT using Tat-conjugated IgM antibodies labeled with a fluorescent dye and radioisotope. • This probes could be used to overcome limitation of conventional antibody imaging system in live cell imaging. • This system could be applicable to monitor intracellular and intranuclear proteins in vitro and in vivo.

  17. A new fluorescence/PET probe for targeting intracellular human telomerase reverse transcriptase (hTERT) using Tat peptide-conjugated IgM

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung oh [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Youn, Hyewon, E-mail: hwyoun@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Cancer Imaging Center, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Seung Hoo [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kim, Young-Hwa [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kang, Keon Wook [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Chung, June-Key, E-mail: jkchung@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of)

    2016-08-26

    Despite an increasing need for methods to visualize intracellular proteins in vivo, the majority of antibody-based imaging methods available can only detect membrane proteins. The human telomerase reverse transcriptase (hTERT) is an intracellular target of great interest because of its high expression in several types of cancer. In this study, we developed a new probe for hTERT using the Tat peptide. An hTERT antibody (IgG or IgM) was conjugated with the Tat peptide, a fluorescence dye and {sup 64}Cu. HT29 (hTERT+) and U2OS (hTERT−) were used to visualize the intracellular hTERT. The hTERT was detected by RT-PCR and western blot. Fluorescence signals for hTERT were obtained by confocal microscopy, live cell imaging, and analyzed by Tissue-FAXS. In nude mice, tumors were visualized using the fluorescence imaging devices Maestro™ and PETBOX. In RT-PCR and western blot, the expression of hTERT was detected in HT29 cells, but not in U2OS cells. Fluorescence signals were clearly observed in HT29 cells and in U2OS cells after 1 h of treatment, but signals were only detected in HT29 cells after 24 h. Confocal microscopy showed that 9.65% of U2OS and 78.54% of HT29 cells had positive hTERT signals. 3D animation images showed that the probe could target intranuclear hTERT in the nucleus. In mice models, fluorescence and PET imaging showed that hTERT in HT29 tumors could be efficiently visualized. In summary, we developed a new method to visualize intracellular and intranuclear proteins both in vitro and in vivo. - Highlights: • We developed new probes for imaging hTERT using Tat-conjugated IgM antibodies labeled with a fluorescent dye and radioisotope. • This probes could be used to overcome limitation of conventional antibody imaging system in live cell imaging. • This system could be applicable to monitor intracellular and intranuclear proteins in vitro and in vivo.

  18. Peptide-Based Selective Inhibitors of Matrix Metalloproteinase-Mediated Activities

    Directory of Open Access Journals (Sweden)

    Margaret W. Ndinguri

    2012-11-01

    Full Text Available The matrix metalloproteinases (MMPs exhibit a broad array of activities, some catalytic and some non-catalytic in nature. An overall lack of selectivity has rendered small molecule, active site targeted MMP inhibitors problematic in execution. Inhibitors that favor few or individual members of the MMP family often take advantage of interactions outside the enzyme active site. We presently focus on peptide-based MMP inhibitors and probes that do not incorporate conventional Zn2+ binding groups. In some cases, these inhibitors and probes function by binding only secondary binding sites (exosites, while others bind both exosites and the active site. A myriad of MMP mediated-activities beyond selective catalysis can be inhibited by peptides, particularly cell adhesion, proliferation, motility, and invasion. Selective MMP binding peptides comprise highly customizable, unique imaging agents. Areas of needed improvement for MMP targeting peptides include binding affinity and stability.

  19. Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338†

    OpenAIRE

    Meyer, Sven W.; Mordhorst, Thorsten F.; Lee, Choonghwan; Jensen, Paul R.; Fenical, William; Köck, Matthias

    2010-01-01

    A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments.

  20. Purification of Angiotensin Converting Enzyme Inhibitory Peptide Derived From Kacang Goat Meat Protein Hydrolysate

    OpenAIRE

    Jamhari, J; Yusiati, L.M; Suryanto, E; Cahyanto, M.N; Erwanto, Y; Muguruma, M

    2013-01-01

    The objective of this study was to identify the Angiotensin Converting Enzyme (ACE) inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC usi...

  1. Proposal for novel curcumin derivatives as potent inhibitors against Alzheimer's disease: Ab initio molecular simulations on the specific interactions between amyloid-beta peptide and curcumin

    Science.gov (United States)

    Ota, Shintaro; Fujimori, Mitsuki; Ishimura, Hiromi; Shulga, Sergiy; Kurita, Noriyuki

    2017-10-01

    Accumulation of amyloid-β (Aβ) peptides in a brain is closely related with the pathogenesis of Alzheimer's disease. To suppress the production of Aβ peptides, we propose novel curcumin derivatives and investigate their binding properties with the amyloid precursor protein (APP), using protein-ligand docking as well as ab initio molecular simulations. Our proposed derivative (curcumin XIV) is found to have a large binding energy with APP and interacts strongly with the cleavage site Ala19 by secretase. It is thus expected that curcumin XIV can protect APP from the secretase attack and be a potent inhibitor against the production of Aβ peptides.

  2. Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation.

    Science.gov (United States)

    Yang, Yoosoo; Kong, Byoungjae; Jung, Younghoon; Park, Joon-Bum; Oh, Jung-Mi; Hwang, Jaesung; Cho, Jae Youl; Kweon, Dae-Hyuk

    2018-01-01

    Vesicle-associated V-soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans -SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.

  3. Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338†

    Science.gov (United States)

    Meyer, Sven W.; Mordhorst, Thorsten F.; Lee, Choonghwan; Jensen, Paul R.; Fenical, William; Köck, Matthias

    2013-01-01

    A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments. PMID:20401392

  4. Synthesis of peptide thioacids at neutral pH using bis(2-sulfanylethyl)amido peptide precursors.

    Science.gov (United States)

    Pira, Silvain L; Boll, Emmanuelle; Melnyk, Oleg

    2013-10-18

    Reaction of bis(2-sulfanylethyl)amido (SEA) peptides with triisopropylsilylthiol in water at neutral pH yields peptide thiocarboxylates. An alkylthioester derived from β-alanine was used to trap the released bis(2-sulfanylethyl)amine and displace the equilibrium toward the peptide thiocarboxylate.

  5. B7H6-derived peptides trigger TNF-α-dependent immunostimulatory activity of lymphocytic NK92-MI cells.

    Science.gov (United States)

    Phillips, Mariana; Romeo, Francesca; Bitsaktsis, Constantine; Sabatino, David

    2016-09-01

    The rise of biologics that can stimulate immune responses towards the eradication of tumors has led to the evolution of cancer-based immunotherapy. Representatively, B7H6 has been recently identified as a protein ligand on tumor cells that binds specifically to the NKp30 receptor and triggers NK cell-derived cytokine production, which ultimately leads to tumor cell lysis and death. In an effort to develop effective immunotherapy approaches, the rational design of a novel class of immunostimulatory peptides (IPs) derived from the binding interface of B7H6:NKp30 is described in this study. The IPs comprised the B7H6 active site sequence for NKp30 binding and immunostimulatory activity. An aminohexanoic acid linker was also introduced at the N-terminus of the peptides for FITC-labeling by Fmoc-solid phase peptide synthesis. The peptides were characterized by LCMS to confirm identities and purities >95%. The secondary structures of the peptides were examined by CD spectroscopy in H2 O, PBS and a H2 O:TFE mixture which demonstrated versatile peptide structures which transitioned from random coil (H2 O) to α-helical (PBS) and turn-type (H2 O:TFE) conformations. Their biological properties were then evaluated by flow cytometry, enzyme-linked immunosorbent assays (ELISAs), and cell death assays. The occupancy of the synthetic peptides to a human NK cell line demonstrated comparable binding relative to the natural NKp30 ligand, B7H6, and the human anti-NKp30 monoclonal antibody (mAb), in a concentration dependent manner. A competitive binding assay between the human anti-NKp30 mAb or B7H6, and the synthetic peptides, demonstrated partial displacement of the ligands upon anti-NKp30 mAb treatment, suggesting NKp30 receptor specificities by the synthetic peptides. Moreover, the immunostimulatory activity of B7H6 was demonstrated by the secretion of the pro-inflammatory cytokines tumor necrosis factor-alfa (TNF-α) and interferon gamma (IFN-γ) by the human NK cell line. The

  6. Mesobuthus Venom-Derived Antimicrobial Peptides Possess Intrinsic Multifunctionality and Differential Potential as Drugs

    Directory of Open Access Journals (Sweden)

    Bin Gao

    2018-02-01

    Full Text Available Animal venoms are a mixture of peptides and proteins that serve two basic biological functions: predation and defense against both predators and microbes. Antimicrobial peptides (AMPs are a common component extensively present in various scorpion venoms (herein abbreviated as svAMPs. However, their roles in predation and defense against predators and potential as drugs are poorly understood. Here, we report five new venom peptides with antimicrobial activity from two Mesobuthus scorpion species. These α-helical linear peptides displayed highly bactericidal activity toward all the Gram-positive bacteria used here but differential activity against Gram-negative bacteria and fungi. In addition to the antibiotic activity, these AMPs displayed lethality to houseflies and hemotoxin-like toxicity on mice by causing hemolysis, tissue damage and inducing inflammatory pain. Unlike AMPs from other origins, these venom-derived AMPs seem to be unsuitable as anti-infective drugs due to their high hemolysis and low serum stability. However, MeuTXKβ1, a known two-domain Mesobuthus AMP, is an exception since it exhibits high activity toward antibiotic resistant Staphylococci clinical isolates with low hemolysis and high serum stability. The findings that the classical AMPs play predatory and defensive roles indicate that the multifunctionality of scorpion venom components is an intrinsic feature likely evolved by natural selection from microbes, prey and predators of scorpions. This definitely provides an excellent system in which one can study how a protein adaptively evolves novel functions in a new environment. Meantimes, new strategies are needed to remove the toxicity of svAMPs on eukaryotic cells when they are used as leads for anti-infective drugs.

  7. Elastin-derived peptides are new regulators of insulin resistance development in mice

    DEFF Research Database (Denmark)

    Blaise, Sébastien; Romier, Béatrice; Kawecki, Charlotte

    2013-01-01

    . In the current study, we show that elastin-derived peptides (EDPs) may be involved in the development of insulin resistance (IRES) in mice. In chow-fed mice, acute or chronic intravenous injections of EDPs induced hyperglycemic effects associated with glucose uptake reduction and IRES in skeletal muscle, liver......, and adipose tissue. Based on in vivo, in vitro, and in silico approaches, we propose that this IRES is due to interaction between the insulin receptor (IR) and the neuraminidase-1 subunit of the elastin receptor complex triggered by EDPs. This interplay was correlated with decreased sialic acid levels...

  8. Peptide p5 binds both heparinase-sensitive glycosaminoglycans and fibrils in patient-derived AL amyloid extracts

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Emily B.; Williams, Angela [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Heidel, Eric [Department of Surgery, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Macy, Sallie [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Kennel, Stephen J. [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Wall, Jonathan S., E-mail: jwall@utmck.edu [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States)

    2013-06-21

    Highlights: •Polybasic peptide p5 binds human light chain amyloid extracts. •The binding of p5 with amyloid involves both glycosaminoglycans and fibrils. •Heparinase treatment led to a correlation between p5 binding and fibril content. •p5 binding to AL amyloid requires electrostatic interactions. -- Abstract: In previously published work, we have described heparin-binding synthetic peptides that preferentially recognize amyloid deposits in a mouse model of reactive systemic (AA) amyloidosis and can be imaged by using positron and single photon emission tomographic imaging. We wanted to extend these findings to the most common form of visceral amyloidosis, namely light chain (AL); however, there are no robust experimental animal models of AL amyloidosis. To further define the binding of the lead peptide, p5, to AL amyloid, we characterized the reactivity in vitro of p5 with in situ and patient-derived AL amyloid extracts which contain both hypersulfated heparan sulfate proteoglycans as well as amyloid fibrils. Histochemical staining demonstrated that the peptide specifically localized with tissue-associated AL amyloid deposits. Although we anticipated that p5 would undergo electrostatic interactions with the amyloid-associated glycosaminoglycans expressing heparin-like side chains, no significant correlation between peptide binding and glycosaminoglycan content within amyloid extracts was observed. In contrast, following heparinase I treatment, although overall binding was reduced, a positive correlation between peptide binding and amyloid fibril content became evident. This interaction was further confirmed using synthetic light chain fibrils that contain no carbohydrates. These data suggest that p5 can bind to both the sulfated glycosaminoglycans and protein fibril components of AL amyloid. Understanding these complex electrostatic interactions will aid in the optimization of synthetic peptides for use as amyloid imaging agents and potentially as

  9. Role of αA-crystallin-derived αA66-80 peptide in guinea pig lens crystallin aggregation and insolubilization.

    Science.gov (United States)

    Raju, Murugesan; Mooney, Brian P; Thakkar, Kavi M; Giblin, Frank J; Schey, Kevin L; Sharma, K Krishna

    2015-03-01

    Earlier we reported that low molecular weight (LMW) peptides accumulate in aging human lens tissue and that among the LMW peptides, the chaperone inhibitor peptide αA66-80, derived from α-crystallin protein, is one of the predominant peptides. We showed that in vitro αA66-80 induces protein aggregation. The current study was undertaken to determine whether LMW peptides are also present in guinea pig lens tissue subjected to hyperbaric oxygen (HBO) in vivo. The nuclear opacity induced by HBO in guinea pig lens is the closest animal model for studying age-related cataract formation in humans. A LMW peptide profile by mass spectrometry showed the presence of an increased amount of LMW peptides in HBO-treated guinea pig lenses compared to age-matched controls. Interestingly, the mass spectrometric data also showed that the chaperone inhibitor peptide αA66-80 accumulates in HBO-treated guinea pig lens. Following incubation of synthetic chaperone inhibitor peptide αA66-80 with α-crystallin from guinea pig lens extracts, we observed a decreased ability of α-crystallin to inhibit the amorphous aggregation of the target protein alcohol dehydrogenase and the formation of large light scattering aggregates, similar to those we have observed with human α-crystallin and αA66-80 peptide. Further, time-lapse recordings showed that a preformed complex of α-crystallin and αA66-80 attracted additional crystallin molecules to form even larger aggregates. These results demonstrate that LMW peptide-mediated cataract development in aged human lens and in HBO-induced lens opacity in the guinea pig may have common molecular pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Facile Synthesis of Mesocrystalline SnO2 Nanorods on Reduced Graphene Oxide Sheets: An Appealing Multifunctional Affinity Probe for Sequential Enrichment of Endogenous Peptides and Phosphopeptides.

    Science.gov (United States)

    Ma, Wen; Zhang, Feng; Li, Liping; Chen, Shuai; Qi, Limin; Liu, Huwei; Bai, Yu

    2016-12-28

    A novel multifunctional composite comprising mesocrystalline SnO 2 nanorods (NRs) vertically aligned on reduced graphene oxide (rGO) sheets was synthesized and developed for sequential capture of endogenous peptides and phosphopeptides. With the hydrophobicity of rGO and high affinity of SnO 2 nanorods, sequential enrichment of endogenous peptides and phosphopeptides could be easily achieved through a modulation of elution buffer. With this multifunctional nanomaterial, 36 peptides were observed from diluted bovine serum albumin (BSA) tryptic digest and 4 phosphopeptides could be selectively captured from β-casein digest. The detection limit of tryptic digest of β-casein was low to 4 × 10 -10 M, and the selectivity was up to 1:500 (molar ratio of β-casein and BSA digest). The effectiveness and robustness of rGO-SnO 2 NRs in a complex biological system was also confirmed by using human serum as a real sample. Our work is promising for small peptide enrichment and identification especially in complicated biological sample preparation, which also opens a new perspective in the design of multifunctional affinity probes for proteome or peptidome.

  11. Influence of probe geometry on the response of an electrostatic probe

    DEFF Research Database (Denmark)

    Johansson, Torben; Crichton, George C; McAllister, Iain Wilson

    1999-01-01

    The response of an electrostatic probe is examined with reference to the probe geometry. The study involves the evaluation of the probe lambda function, from which response-related characteristic parameters can be derived. These parameters enable the probe detection sensitivity Se and spatial...

  12. Peptide-membrane Interactions by Spin-labeling EPR

    Science.gov (United States)

    Smirnova, Tatyana I.; Smirnov, Alex I.

    2016-01-01

    Site-directed spin labeling (SDSL) in combination with Electron Paramagnetic Resonance (EPR) spectroscopy is a well-established method that has recently grown in popularity as an experimental technique, with multiple applications in protein and peptide science. The growth is driven by development of labeling strategies, as well as by considerable technical advances in the field, that are paralleled by an increased availability of EPR instrumentation. While the method requires an introduction of a paramagnetic probe at a well-defined position in a peptide sequence, it has been shown to be minimally destructive to the peptide structure and energetics of the peptide-membrane interactions. In this chapter, we describe basic approaches for using SDSL EPR spectroscopy to study interactions between small peptides and biological membranes or membrane mimetic systems. We focus on experimental approaches to quantify peptide-membrane binding, topology of bound peptides, and characterize peptide aggregation. Sample preparation protocols including spin-labeling methods and preparation of membrane mimetic systems are also described. PMID:26477253

  13. The antibacterial activity of peptides derived from human beta-2 glycoprotein I is inhibited by protein H and M1 protein from Streptococcus pyogenes

    NARCIS (Netherlands)

    Nilsson, Maria; Wasylik, Sylwia; Mörgelin, Matthias; Olin, Anders I.; Meijers, Joost C. M.; Derksen, Ronald H. W. M.; de Groot, Philip G.; Herwald, Heiko

    2008-01-01

    During the last years, the importance of antibacterial peptides has attracted considerable attention. We report here that peptides derived from the fifth domain of beta-2 glycoprotein I (beta(2)GPI), a human heparin binding plasma protein, have antibacterial activities against Gram-positive and

  14. Zein nanoparticle as a novel BMP6 derived peptide carrier for enhanced osteogenic differentiation of C2C12 cells.

    Science.gov (United States)

    Hadavi, Mahvash; Hasannia, Sadegh; Faghihi, Shahab; Mashayekhi, Farhad; Homazadeh, Homayoun; Mostofi, Seyed Behrooz

    2018-01-26

    Zein nanoparticles as a carrier system for BMP6-derived peptide were prepared by liquid-liquid phase separation procedure and characterized with SEM, DLS, FTIR and thermogravimetric methods. After peptide encapsulation, nanoparticle size increased from 236.3 ± 92.2 nm to 379.4 ± 116.8 nm. The encapsulation efficiency of peptide was 72.6% and the release of peptide from Zein nanoparticles was partly sustained in trypsin containing phosphate buffered saline (pH 7.4) for up to 14 days. Peptide-loaded nanoparticles showed similar cell viability compared with blank ones. ALP activity of C2C12 cells treated with peptide-loaded nanoparticles (500 µg/mL) was evaluated 7, 14, 21 and 28 days after culture. In peptide-loaded nanoparticles, ALP activity was significantly higher (p < .05) compared with other groups at day 14. Alizarin Red S staining showed, C2C12 cells behind peptide-loaded nanoparticles had significantly (p < .05) higher calcium deposition at day 21. The results of RT-qPCR show that the BMP-6 peptide activated expression of RUNX2 as a transcription factor. In turn, RUNX2 regulates SPP1 and BGLAP gene expression, as osteogenic marker genes. The results confirm that the peptide-loaded Zein nanoparticles, as osteoinductive material, may be used to repair small area of bone defects, with low load bearing.

  15. A biomimetic colorimetric logic gate system based on multi-functional peptide-mediated gold nanoparticle assembly.

    Science.gov (United States)

    Li, Yong; Li, Wang; He, Kai-Yu; Li, Pei; Huang, Yan; Nie, Zhou; Yao, Shou-Zhuo

    2016-04-28

    In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular activities. Building biomimetic peptide-based bio-logic systems is highly intriguing but remains relatively unexplored due to limited logic recognition elements and complex signal outputs. In this proof-of-principle work, we attempted to address these problems by utilizing multi-functional peptide probes and the peptide-mediated nanoparticle assembly system. Here, the rationally designed peptide probes function as the dual-target responsive element specifically responsive to metal ions and enzymes as well as the mediator regulating the assembly of gold nanoparticles (AuNPs). Taking advantage of Zn2+ ions and chymotrypsin as the model inputs of metal ions and enzymes, respectively, we constructed the peptide logic system computed by the multi-functional peptide probes and outputted by the readable colour change of AuNPs. In this way, the representative binary basic logic gates (AND, OR, INHIBIT, NAND, IMPLICATION) have been achieved by delicately coding the peptide sequence, demonstrating the versatility of our logic system. Additionally, we demonstrated that the three-input combinational logic gate (INHIBIT-OR) could also be successfully integrated and applied as a multi-tasking biosensor for colorimetric detection of dual targets. This nanoparticle-based peptide logic system presents a valid strategy to illustrate peptide information processing and provides a practical platform for executing peptide computing or peptide-related multiplexing sensing, implying that the controllable nanomaterial assembly is a promising and potent methodology for the advancement of biomimetic bio-logic computation.

  16. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Yerly Vargas Casanova

    2017-09-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922 and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  17. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines.

    Science.gov (United States)

    Vargas Casanova, Yerly; Rodríguez Guerra, Jorge Antonio; Umaña Pérez, Yadi Adriana; Leal Castro, Aura Lucía; Almanzar Reina, Giovanni; García Castañeda, Javier Eduardo; Rivera Monroy, Zuly Jenny

    2017-09-29

    Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  18. Morphofunctional reaction of bacteria treated with antimicrobial peptides derived from farm animal platelets.

    Science.gov (United States)

    Vasilchenko, Alexey S; Dymova, Veronica V; Kartashova, Olga L; Sycheva, Maria V

    2015-03-01

    Classical microbiological approach and atomic force microscopy were used to evaluate the mechanisms of biological activity of antimicrobial peptides (AMPs) derived from platelets of farm animals. It is established that AMPs inhibit both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Differences revealed in the biological activity of AMP preparations obtained from the organisms of various species can be reduced to quantitative differences. While qualitative changes of bacterial cells were substantially similar, changes in the integrity of cell walls resulted in disintegration of the bacterial outer and/or cytoplasmic membranes.

  19. Peptide nucleic acid probe for protein affinity purification based on biotin-streptavidin interaction and peptide nucleic acid strand hybridization.

    Science.gov (United States)

    Tse, Jenny; Wang, Yuanyuan; Zengeya, Thomas; Rozners, Eriks; Tan-Wilson, Anna

    2015-02-01

    We describe a new method for protein affinity purification that capitalizes on the high affinity of streptavidin for biotin but does not require dissociation of the biotin-streptavidin complex for protein retrieval. Conventional reagents place both the selectively reacting group (the "warhead") and the biotin on the same molecule. We place the warhead and the biotin on separate molecules, each linked to a short strand of peptide nucleic acid (PNA), synthetic polymers that use the same bases as DNA but attached to a backbone that is resistant to attack by proteases and nucleases. As in DNA, PNA strands with complementary base sequences hybridize. In conditions that favor PNA duplex formation, the warhead strand (carrying the tagged protein) and the biotin strand form a complex that is held onto immobilized streptavidin. As in DNA, the PNA duplex dissociates at moderately elevated temperature; therefore, retrieval of the tagged protein is accomplished by a brief exposure to heat. Using iodoacetate as the warhead, 8-base PNA strands, biotin, and streptavidin-coated magnetic beads, we demonstrate retrieval of the cysteine protease papain. We were also able to use our iodoacetyl-PNA:PNA-biotin probe for retrieval and identification of a thiol reductase and a glutathione transferase from soybean seedling cotyledons. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. 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.

  1. Fluorescence In Situ Hybridization with Peptide Nucleic Acid Probes for Rapid Identification of Candida albicans Directly from Blood Culture Bottles

    Science.gov (United States)

    Rigby, Susan; Procop, Gary W.; Haase, Gerhard; Wilson, Deborah; Hall, Geraldine; Kurtzman, Cletus; Oliveira, Kenneth; Von Oy, Sabina; Hyldig-Nielsen, Jens J.; Coull, James; Stender, Henrik

    2002-01-01

    A new fluorescence in situ hybridization (FISH) method that uses peptide nucleic acid (PNA) probes for identification of Candida albicans directly from positive-blood-culture bottles in which yeast was observed by Gram staining (herein referred to as yeast-positive blood culture bottles) is described. The test (the C. albicans PNA FISH method) is based on a fluorescein-labeled PNA probe that targets C. albicans 26S rRNA. The PNA probe is added to smears made directly from the contents of the blood culture bottle and hybridized for 90 min at 55°C. Unhybridized PNA probe is removed by washing of the mixture (30 min), and the smears are examined by fluorescence microscopy. The specificity of the method was confirmed with 23 reference strains representing phylogenetically related yeast species and 148 clinical isolates covering the clinically most significant yeast species, including C. albicans (n = 72), C. dubliniensis (n = 58), C. glabrata (n = 5), C. krusei (n = 2), C. parapsilosis (n = 4), and C. tropicalis (n = 3). The performance of the C. albicans PNA FISH method as a diagnostic test was evaluated with 33 routine and 25 simulated yeast-positive blood culture bottles and showed 100% sensitivity and 100% specificity. It is concluded that this 2.5-h method for the definitive identification of C. albicans directly from yeast-positive blood culture bottles provides important information for optimal antifungal therapy and patient management. PMID:12037084

  2. Rapid Identification of Staphylococcus aureus Directly from Blood Cultures by Fluorescence In Situ Hybridization with Peptide Nucleic Acid Probes

    Science.gov (United States)

    Oliveira, Kenneth; Procop, Gary W.; Wilson, Deborah; Coull, James; Stender, Henrik

    2002-01-01

    A new fluorescence in situ hybridization (FISH) method with peptide nucleic acid (PNA) probes for identification of Staphylococcus aureus directly from positive blood culture bottles that contain gram-positive cocci in clusters (GPCC) is described. The test (the S. aureus PNA FISH assay) is based on a fluorescein-labeled PNA probe that targets a species-specific sequence of the 16S rRNA of S. aureus. Evaluations with 17 reference strains and 48 clinical isolates, including methicillin-resistant and methicillin-susceptible S. aureus species, coagulase-negative Staphylococcus species, and other clinically relevant and phylogenetically related bacteria and yeast species, showed that the assay had 100% sensitivity and 96% specificity. Clinical trials with 87 blood cultures positive for GPCC correctly identified 36 of 37 (97%) of the S. aureus-positive cultures identified by standard microbiological methods. The positive and negative predictive values were 100 and 98%, respectively. It is concluded that this rapid method (2.5 h) for identification of S. aureus directly from blood culture bottles that contain GPCC offers important information for optimal antibiotic therapy. PMID:11773123

  3. A PEDF-Derived Peptide Inhibits Retinal Neovascularization and Blocks Mobilization of Bone Marrow-Derived Endothelial Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Richard Longeras

    2012-01-01

    Full Text Available Proliferative diabetic retinopathy is characterized by pathological retinal neovascularization, mediated by both angiogenesis (involving mature endothelial cells and vasculogenesis (involving bone marrow-derived circulating endothelial progenitor cells (EPCs. Pigment epithelium-derived factor (PEDF contains an N-terminal 34-amino acid peptide (PEDF-34 that has antiangiogenic properties. Herein, we present a novel finding that PEDF-34 also possesses antivasculogenic activity. In the oxygen-induced retinopathy (OIR model using transgenic mice that have Tie2 promoter-driven GFP expression, we quantified Tie2GFP+ cells in bone marrow and peripheral blood by fluorescence-activated cell sorting (FACS. OIR significantly increased the number of circulating Tie2-GFP+ at P16, correlating with the peak progression of neovascularization. Daily intraperitoneal injections of PEDF-34 into OIR mice decreased the number of Tie2-GFP+ cells in the circulation at P16 by 65% but did not affect the number of Tie2-GFP+ cells in the bone marrow. These studies suggest that PEDF-34 attenuates EPC mobilization from the bone marrow into the blood circulation during retinal neovascularization.

  4. Deglycosylation of chondroitin sulfate proteoglycan and derived peptides

    International Nuclear Information System (INIS)

    Campbell, S.C.; Krueger, R.C.; Schwartz, N.B.

    1990-01-01

    In order to define the domain structure of proteoglycans as well as identify primary amino acid sequences specific for attachment of the various carbohydrate substituents, reliable techniques for deglycosylating proteoglycans are required. In this study, deglycosylation of cartilage chondroitin sulfate proteoglycan (CSPG) with minimal core protein cleavage was accomplished by digestion with chondroitinase ABC and keratanase, followed by treatment with anhydrous HF in pyridine. Nearly complete deglycosylation of secreted proteoglycan was verified within 45 min of HF treatment by loss of incorporated [ 3 H]glucosamine label from the proteoglycan as a function of time of treatment, as well as by direct analysis of carbohydrate content and xylosyltransferase acceptor activity of unlabeled core protein preparations. The deglycosylated CSPG preparations were homogeneous and of high molecular weight. Comparison of the intact deglycosylated core protein preparations with newly synthesized unprocessed precursors suggested that extensive proteolytic cleavage of the core protein did not occur during normal intracellular processing. Furthermore, peptide patterns generated after clostripain digestion of core protein precursor and of deglycosylated secreted proteoglycan were comparable. With the use of the clostripain digestion procedure, peptides were produced from unlabeled proteoglycan, and two predominant peptides from the most highly glycosylated regions were isolated, characterized, and deglycosylated. These peptides were found to follow similar kinetics of deglycosylation and to acquire xylose activity comparable to the intact core protein

  5. Multi-species sequence comparison reveals conservation of ghrelin gene-derived splice variants encoding a truncated ghrelin peptide.

    Science.gov (United States)

    Seim, Inge; Jeffery, Penny L; Thomas, Patrick B; Walpole, Carina M; Maugham, Michelle; Fung, Jenny N T; Yap, Pei-Yi; O'Keeffe, Angela J; Lai, John; Whiteside, Eliza J; Herington, Adrian C; Chopin, Lisa K

    2016-06-01

    The peptide hormone ghrelin is a potent orexigen produced predominantly in the stomach. It has a number of other biological actions, including roles in appetite stimulation, energy balance, the stimulation of growth hormone release and the regulation of cell proliferation. Recently, several ghrelin gene splice variants have been described. Here, we attempted to identify conserved alternative splicing of the ghrelin gene by cross-species sequence comparisons. We identified a novel human exon 2-deleted variant and provide preliminary evidence that this splice variant and in1-ghrelin encode a C-terminally truncated form of the ghrelin peptide, termed minighrelin. These variants are expressed in humans and mice, demonstrating conservation of alternative splicing spanning 90 million years. Minighrelin appears to have similar actions to full-length ghrelin, as treatment with exogenous minighrelin peptide stimulates appetite and feeding in mice. Forced expression of the exon 2-deleted preproghrelin variant mirrors the effect of the canonical preproghrelin, stimulating cell proliferation and migration in the PC3 prostate cancer cell line. This is the first study to characterise an exon 2-deleted preproghrelin variant and to demonstrate sequence conservation of ghrelin gene-derived splice variants that encode a truncated ghrelin peptide. This adds further impetus for studies into the alternative splicing of the ghrelin gene and the function of novel ghrelin peptides in vertebrates.

  6. High-affinity human leucocyte antigen class I binding variola-derived peptides induce CD4(+) T cell responses more than 30 years post-vaccinia virus vaccination

    DEFF Research Database (Denmark)

    Wang, M.; Tang, Sheila Tuyet; Lund, Ole

    2009-01-01

    Interferon-gamma secreting T lymphocytes against pox virus-derived synthetic 9-mer peptides were tested by enzyme-linked immunospot in peripheral blood of individuals vaccinated with vaccinia virus more than 30 years ago. The peptides were characterized biochemically as high-affinity human leucoc...

  7. Biosynthesis of 2-aminooctanoic acid and its use to terminally modify a lactoferricin B peptide derivative for improved antimicrobial activity.

    Science.gov (United States)

    Almahboub, Sarah A; Narancic, Tanja; Devocelle, Marc; Kenny, Shane T; Palmer-Brown, William; Murphy, Cormac; Nikodinovic-Runic, Jasmina; O'Connor, Kevin E

    2018-01-01

    Terminal modification of peptides is frequently used to improve their hydrophobicity. While N-terminal modification with fatty acids (lipidation) has been reported previously, C-terminal lipidation is limited as it requires the use of linkers. Here we report the use of a biocatalyst for the production of an unnatural fatty amino acid, (S)-2-aminooctanoic acid (2-AOA) with enantiomeric excess > 98% ee and the subsequent use of 2-AOA to modify and improve the activity of an antimicrobial peptide. A transaminase originating from Chromobacterium violaceum was employed with a conversion efficiency 52-80% depending on the ratio of amino group donor to acceptor. 2-AOA is a fatty acid with amino functionality, which allowed direct C- and N-terminal conjugation respectively to an antimicrobial peptide (AMP) derived from lactoferricin B. The antibacterial activity of the modified peptides was improved by up to 16-fold. Furthermore, minimal inhibitory concentrations (MIC) of C-terminally modified peptide were always lower than N-terminally conjugated peptides. The C-terminally modified peptide exhibited MIC values of 25 μg/ml for Escherichia coli, 50 μg/ml for Bacillus subtilis, 100 μg/ml for Salmonella typhimurium, 200 μg/ml for Pseudomonas aeruginosa and 400 μg/ml for Staphylococcus aureus. The C-terminally modified peptide was the only peptide tested that showed complete inhibition of growth of S. aureus.

  8. Tumor-targeting peptides from combinatorial libraries*

    Science.gov (United States)

    Liu, Ruiwu; Li, Xiaocen; Xiao, Wenwu; Lam, Kit S.

    2018-01-01

    Cancer is one of the major and leading causes of death worldwide. Two of the greatest challenges infighting cancer are early detection and effective treatments with no or minimum side effects. Widespread use of targeted therapies and molecular imaging in clinics requires high affinity, tumor-specific agents as effective targeting vehicles to deliver therapeutics and imaging probes to the primary or metastatic tumor sites. Combinatorial libraries such as phage-display and one-bead one-compound (OBOC) peptide libraries are powerful approaches in discovering tumor-targeting peptides. This review gives an overview of different combinatorial library technologies that have been used for the discovery of tumor-targeting peptides. Examples of tumor-targeting peptides identified from each combinatorial library method will be discussed. Published tumor-targeting peptide ligands and their applications will also be summarized by the combinatorial library methods and their corresponding binding receptors. PMID:27210583

  9. Intrinsic Toxin-Derived Peptides Destabilize and Inactivate Clostridium difficile TcdB

    Directory of Open Access Journals (Sweden)

    Jason L. Larabee

    2017-05-01

    Full Text Available Clostridium difficile infection (CDI is a major cause of hospital-associated, antibiotic-induced diarrhea, which is largely mediated by the production of two large multidomain clostridial toxins, TcdA and TcdB. Both toxins coordinate the action of specific domains to bind receptors, enter cells, and deliver a catalytic fragment into the cytosol. This results in GTPase inactivation, actin disassembly, and cytotoxicity. TcdB in particular has been shown to encode a region covering amino acids 1753 to 1851 that affects epitope exposure and cytotoxicity. Surprisingly, studies here show that several peptides derived from this region, which share the consensus sequence 1769NVFKGNTISDK1779, protect cells from the action of TcdB. One peptide, PepB2, forms multiple interactions with the carboxy-terminal region of TcdB, destabilizes TcdB structure, and disrupts cell binding. We further show that these effects require PepB2 to form a higher-order polymeric complex, a process that requires the central GN amino acid pair. These data suggest that TcdB1769–1779 interacts with repeat sequences in the proximal carboxy-terminal domain of TcdB (i.e., the CROP domain to alter the conformation of TcdB. Furthermore, these studies provide insights into TcdB structure and functions that can be exploited to inactivate this critical virulence factor and ameliorate the course of CDI.

  10. Optimization of hydrolysis conditions, isolation, and identification of neuroprotective peptides derived from seahorse Hippocampus trimaculatus.

    Science.gov (United States)

    Pangestuti, Ratih; Ryu, Bomi; Himaya, Swa; Kim, Se-Kwon

    2013-08-01

    Hippocampus trimaculatus is one of the most heavily traded seahorse species for traditional medicine purposes in many countries. In the present study, we showed neuroprotective effects of peptide derived from H. trimaculatus against amyloid-β42 (Aβ42) toxicity which are central to the pathogenesis of Alzheimer's diseases (AD). Firstly, H. trimaculatus was separately hydrolyzed by four different enzymes and tested for their protective effect on Aβ42-induced neurotoxicity in differentiated PC12 cells. Pronase E hydrolysate exerted highest protection with cell viability value of 88.33 ± 3.33 %. Furthermore, we used response surface methodology to optimize pronase E hydrolysis conditions and found that temperature at 36.69 °C with the hydrolysis time 20.01 h, enzyme to substrate (E/S) ratio of 2.02 % and pH 7.34 were the most optimum conditions. Following several purification steps, H. trimaculatus-derived neuroprotective peptides (HTP-1) sequence was identified as Gly-Thr-Glu-Asp-Glu-Leu-Asp-Lys (906.4 Da). HTP-1 protected PC12 cells from Aβ42-induced neuronal death with the cell viability value of 85.52 ± 2.22 % and up-regulated pro-survival gene (Bcl-2) expressions. These results suggest that HTP-1 has the potential to be used in treatment of neurodegenerative diseases, particularly AD. Identification, characterization, and synthesis of bioactive components derived from H. trimaculatus have the potential to replace or at least complement the use of seahorse as traditional medicine, which further may become an approach to minimize seahorse exploitation in traditional medicine.

  11. Plasmon based biosensor for distinguishing different peptides mutation states

    KAUST Repository

    Das, Gobind

    2013-05-08

    Periodic and reproducible gold nanocuboids with various matrix dimensions and with different inter-particle gaps were fabricated by means of top-down technique. Rhodamine 6G was used as a probe molecule to optimize the design and the fabrication of the cuboid nanostructures. The electric field distribution for the nanocuboids with varying matrix dimensions/inter-particle gap was also investigated. These SERS devices were employed as biosensors through the investigation of both myoglobin and wild/mutated peptides. The results demonstrate the probing and the screening of wild/mutated BRCA1 peptides, thus opening a path for the fabrication of simple and cheap SERS device capable of early detection of several diseases.

  12. NMR structures of anti-HIV D-peptides derived from the N-terminus of viral chemokine vMIP-II

    International Nuclear Information System (INIS)

    Mori, Mayuko; Liu Dongxiang; Kumar, Santosh; Huang Ziwei

    2005-01-01

    The viral macrophage inflammatory protein-II (vMIP-II) encoded by Kaposi's sarcoma-associated herpesvirus has unique biological activities in that it blocks the cell entry by several different human immunodeficiency virus type 1 (HIV-1) strains via chemokine receptors including CXCR4 and CCR5. In this paper, we report the solution structure of all-D-amino acid peptides derived from the N-terminus of vMIP-II, which have been shown to have strong CXCR4 binding activity and potently inhibit HIV-1 entry via CXCR4, by using long mixing time two-dimensional nuclear Overhauser enhancement spectroscopy experiments. Both of all-D-peptides vMIP-II (1-10) and vMIP-II (1-21), which are designated as DV3 and DV1, respectively, have higher CXCR4 binding ability than their L-peptide counterparts. They are partially structured in aqueous solution, displaying a turn-like structure over residues 5-8. The small temperature coefficients of His-6 amide proton for both peptides also suggest the formation of a small hydrophobic pocket centered on His-6. The structural features of DV3 are very similar to the reported solution structure of all-L-peptide vMIP-II (1-10) [M.P. Crump, E. Elisseeva, J. Gong, I. Clark-Lewis, B.D. Sykes, Structure/function of human herpesvirus-8 MIP-II (1-71) and the antagonist N-terminal segment (1-10), FEBS Lett. 489 (2001) 171], which is consistent with the notion that D- and L-enantiomeric peptides can adopt mirror image conformations. The NMR structures of the D-peptides provide a structural basis to understand their mechanism of action and design new peptidomimetic analogs to further explore the structure-activity relationship of D-peptide ligand binding to CXCR4

  13. Acute ingestion of a novel whey-derived peptide improves vascular endothelial responses in healthy individuals: a randomized, placebo controlled trial

    Directory of Open Access Journals (Sweden)

    Kupchak Brian R

    2009-07-01

    Full Text Available Abstract Background Whey protein is a potential source of bioactive peptides. Based on findings from in vitro experiments indicating a novel whey derived peptide (NOP-47 increased endothelial nitric oxide synthesis, we tested its effects on vascular function in humans. Methods A randomized, placebo-controlled, crossover study design was used. Healthy men (n = 10 and women (n = 10 (25 ± 5 y, BMI = 24.3 ± 2.3 kg/m2 participated in two vascular testing days each preceded by 2 wk of supplementation with a single dose of 5 g/day of a novel whey-derived peptide (NOP-47 or placebo. There was a 2 wk washout period between trials. After 2 wk of supplementation, vascular function in the forearm and circulating oxidative stress and inflammatory related biomarkers were measured serially for 2 h after ingestion of 5 g of NOP-47 or placebo. Macrovascular and microvascular function were assessed using brachial artery flow mediated dilation (FMD and venous occlusion strain gauge plethysmography. Results Baseline peak FMD was not different for Placebo (7.7% and NOP-47 (7.8%. Placebo had no effect on FMD at 30, 60, and 90 min post-ingestion (7.5%, 7.2%, and 7.6%, respectively whereas NOP-47 significantly improved FMD responses at these respective postprandial time points compared to baseline (8.9%, 9.9%, and 9.0%; P P = 0.008 for time × trial interaction. Plasma myeloperoxidase was increased transiently by both NOP-47 and placebo, but there were no changes in markers inflammation. Plasma total nitrites/nitrates significantly decreased over the 2 hr post-ingestion period and were lower at 120 min after placebo (-25% compared to NOP-47 (-18%. Conclusion These findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function.

  14. Gephyrin-binding peptides visualize postsynaptic sites and modulate neurotransmission

    DEFF Research Database (Denmark)

    Maric, Hans Michael; Hausrat, Torben Johann; Neubert, Franziska

    2017-01-01

    is associated with perturbation of the basic physiological action. Here we pursue a fundamentally different approach, by instead targeting the intracellular receptor-gephyrin interaction. First, we defined the gephyrin peptide-binding consensus sequence, which facilitated the development of gephyrin super......-binding peptides and later effective affinity probes for the isolation of native gephyrin. Next, we demonstrated that fluorescent super-binding peptides could be used to directly visualize inhibitory postsynaptic sites for the first time in conventional and super-resolution microscopy. Finally, we demonstrate...

  15. Second derivative Langmuir probe diagnostics of gas discharge plasma at intermediate pressures (review article)

    International Nuclear Information System (INIS)

    Popov, Tsv K; Dimitrova, M; Dias, F M; Tsaneva, V N; Stelmashenko, N A; Blamire, M G; Barber, Z H

    2006-01-01

    The second-derivative Langmuir probe method for precise determination of the plasma potential, the electron energy distribution function (respectively the electron temperature,) and the electron density of gas discharge plasma at intermediate pressures (100-1000 Pa) is reviewed. Results of applying the procedure proposed to different kinds of gas discharges are presented. Factors affecting the accuracy of the plasma characteristics evaluated are discussed

  16. Biophysical analysis of the interaction of granulysin-derived peptides with enterobacterial endotoxins.

    Science.gov (United States)

    Chen, Xi; Howe, Jörg; Andrä, Jörg; Rössle, Manfred; Richter, Walter; da Silva, Ana Paula Galvão; Krensky, Alan M; Clayberger, Carol; Brandenburg, Klaus

    2007-10-01

    To combat infections by Gram-negative bacteria, it is not only necessary to kill the bacteria but also to neutralize pathogenicity factors such as endotoxin (lipopolysaccharide, LPS). The development of antimicrobial peptides based on mammalian endotoxin-binding proteins is a promising tool in the fight against bacterial infections, and septic shock syndrome. Here, synthetic peptides derived from granulysin (Gra-pep) were investigated in microbiological and biophysical assays to understand their interaction with LPS. We analyzed the influence of the binding of Gra-pep on (1) the acyl chain melting of the hydrophobic moiety of LPS, lipid A, by Fourier-transform spectroscopy, (2) the aggregate structure of LPS by small-angle X-ray scattering and cryo-transmission electron microscopy, and 3) the enthalpy change by isothermal titration calorimetry. In addition, the influence of Gra-pep on the incorporation of LPS and LPS-LBP (lipopolysaccharide-binding protein) complexes into negatively charged liposomes was monitored. Our findings demonstrate a characteristic change in the aggregate structure of LPS into multilamellar stacks in the presence of Gra-pep, but little or no change of acyl chain fluidity. Neutralization of LPS by Gra-pep is not due to a scavenging effect in solution, but rather proceeds after incorporation into target membranes, suggesting a requisite membrane-bound step.

  17. Evaluation of 18F-labeled exendin(9-39) derivatives targeting glucagon-like peptide-1 receptor for pancreatic β-cell imaging.

    Science.gov (United States)

    Kimura, Hiroyuki; Ogawa, Yu; Fujimoto, Hiroyuki; Mukai, Eri; Kawashima, Hidekazu; Arimitsu, Kenji; Toyoda, Kentaro; Fujita, Naotaka; Yagi, Yusuke; Hamamatsu, Keita; Murakami, Takaaki; Murakami, Atsushi; Ono, Masahiro; Nakamoto, Yuji; Togashi, Kaori; Inagaki, Nobuya; Saji, Hideo

    2018-01-15

    β-cell mass (BCM) is known to be decreased in subjects with type-2 diabetes (T2D). Quantitative analysis for BCM would be useful for understanding how T2D progresses and how BCM affects treatment efficacy and for earlier diagnosis of T2D and development of new therapeutic strategies. However, a noninvasive method to measure BCM has not yet been developed. We developed four 18 F-labeled exendin(9-39) derivatives for β-cell imaging by PET: [ 18 F]FB9-Ex(9-39), [ 18 F]FB12-Ex(9-39), [ 18 F]FB27-Ex(9-39), and [ 18 F]FB40-Ex(9-39). Affinity to the glucagon-like peptide-1 receptor (GLP-1R) was evaluated with dispersed islet cells of ddY mice. Uptake of exendin(9-39) derivatives in the pancreas as well as in other organs was evaluated by a biodistribution study. Small-animal PET study was performed after injecting [ 18 F]FB40-Ex(9-39). FB40-Ex(9-39) showed moderate affinity to the GLP-1R. Among all of the derivatives, [ 18 F]FB40-Ex(9-39) resulted in the highest uptake of radioactivity in the pancreas 30 min after injection. Moreover, it showed significantly less radioactivity accumulated in the liver and kidney, resulting in an overall increase in the pancreas-to-organ ratio. In the PET imaging study, pancreas was visualized at 30 min after injection of [ 18 F]FB40-Ex(9-39). [ 18 F]FB40-Ex(9-39) met the basic requirements for an imaging probe for GLP-1R in pancreatic β-cells. Further enhancement of pancreatic uptake and specific binding to GLP-1R will lead to a clear visualization of pancreatic β-cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Design and application of natural product derived probes for activity based protein profiling

    OpenAIRE

    Battenberg, Oliver Alexander

    2015-01-01

    The identification of new antibacterial protein targets by activity based protein profiling (ABPP) is an important approach to face the increasing emergence of resistant bacteria. The scope of this work focuses on three new strategies for the labeling of antibacterial protein-targets with natural product derived ABPP-probes: A.) Evaluation of the intrinsic photo-reactivity of α-pyrones and pyrimidones for use as photo-crosslinkers. B.) Synthesis of a benzophenone-tag that combines photo-cross...

  19. Peptides in melanoma therapy.

    Science.gov (United States)

    Mocellin, Simone

    2012-01-01

    Peptides derived from tumor associated antigens can be utilized to elicit a therapeutically effective immune response against melanoma in experimental models. However, patient vaccination with peptides - although it is often followed by the induction of melanoma- specific T lymphocytes - is rarely associated with tumor response of clinical relevance. In this review I summarize the principles of peptide design as well as the results so far obtained in the clinical setting while treating cutaneous melanoma by means of this active immunotherapy strategy. I also discuss some immunological and methodological issues that might be helpful for the successful development of peptide-based vaccines.

  20. Antimicrobial Activity of Truncated and Polyvalent Peptides Derived from the FKCRRQWQWRMKKGLA Sequence against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923

    Directory of Open Access Journals (Sweden)

    Nataly de Jesús Huertas

    2017-06-01

    Full Text Available Peptides derived from LfcinB were designed and synthesized, and their antibacterial activity was tested against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Specifically, a peptide library was constructed by systemically removing the flanking residues (N or C-terminal of Lfcin 17–31 (17FKCRRWQWRMKKLGA31, maintaining in all peptides the 20RRWQWR25 sequence that corresponds to the minimal antimicrobial motif. For this research, also included were (i a peptide containing an Ala instead of Cys ([Ala19]-LfcinB 17–31 and (ii polyvalent peptides containing the RRWQWR sequence and a non-natural amino acid (aminocaproic acid. We established that the lineal peptides LfcinB 17–25 and LfcinB 17–26 exhibited the greatest activity against E. coli ATCC 25922 and S. aureus ATCC 25923, respectively. On the other hand, polyvalent peptides, a dimer and a tetramer, exhibited the greatest antibacterial activity, indicating that multiple copies of the sequence increase the activity. Our results suggest that the dimeric and tetrameric sequence forms potentiate the antibacterial activity of lineal sequences that have exhibited moderate antibacterial activity.

  1. A Two-Piece Derivative of a Group I Intron RNA as a Platform for Designing Self-Assembling RNA Templates to Promote Peptide Ligation

    Directory of Open Access Journals (Sweden)

    Takahiro Tanaka

    2012-01-01

    Full Text Available Multicomponent RNA-peptide complexes are attractive from the viewpoint of artificial design of functional biomacromolecular systems. We have developed self-folding and self-assembling RNAs that serve as templates to assist chemical ligation between two reactive peptides with RNA-binding capabilities. The design principle of previous templates, however, can be applied only to limited classes of RNA-binding peptides. In this study, we employed a two-piece derivative of a group I intron RNA from the Tetrahymena large subunit ribosomal RNA (LSU rRNA as a platform for new template RNAs. In this group I intron-based self-assembling platform, modules for the recognition of substrate peptides can be installed independently from modules holding the platform structure. The new self-assembling platform allows us to expand the repertoire of substrate peptides in template RNA design.

  2. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well....... An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  3. Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

    Science.gov (United States)

    Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

    1993-01-01

    The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I. PMID:7682161

  4. Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

    Science.gov (United States)

    Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

    1993-04-01

    The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I.

  5. Alpha-amidated peptides derived from pro-opiomelanocortin in normal human pituitary

    DEFF Research Database (Denmark)

    Fenger, M; Johnsen, A H

    1988-01-01

    Normal human pituitaries were extracted in boiling water and acetic acid, and the alpha-amidated peptide products of pro-opiomelanocortin (POMC), alpha-melanocyte-stimulating hormone (alpha MSH), gamma-melanocyte-stimulating hormone (gamma 1MSH), and amidated hinge peptide (HP-N), as well...... (ACTH)-(1-39), ACTH-(1-14) and alpha MSH immunoreactivity]. alpha MSH and ACTH-(1-14) were only present in non- or mono-acetylated forms. Only large forms of gamma 1MSH and gamma 2MSH were present in partly glycosylated states. The hinge peptides were amidated to an extent two to three orders...... amidated POMC-related peptides are present in normal human pituitary. It also shows that cleavage in vivo at all dibasic amino acids but one, takes place at the N-terminal POMC region; the exception is at the POMC-(49-50) N-terminal of the gamma MSH sequence. The pattern of peptides produced suggests...

  6. Cardioprotective peptides from marine sources.

    Science.gov (United States)

    Harnedy, Padraigín A; FitzGerald, Richard J

    2013-05-01

    Elevated blood pressure or hypertension is one of the fastest growing health problems worldwide. Although the etiology of essential hypertension has a genetic component, dietary factors play an important role. With the high costs and adverse side-effects associated with synthetic antihypertensive drugs and the awareness of the link between diet and health there has been increased focus on identification of food components that may contribute to cardiovascular health. In recent years special interest has been paid to the cardioprotective activity of peptides derived from food proteins including marine proteins. These peptides are latent within the sequence of the parent protein and only become active when released by proteolytic digestion during gastrointestinal digestion or through food processing. Current data on antihypertensive activity of marine-derived protein hydrolysates/peptides in animal and human studies is reviewed herein. Furthermore, products containing protein hydrolysates/peptides from marine origin with antihypertensive effects are discussed.

  7. Evaluation of single amino acid chelate derivatives and regioselective radiolabelling of a cyclic peptide for the urokinase plasminogen activator receptor

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Andrea F.; Lemon, Jennifer A. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Czorny, Shannon K. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Singh, Gurmit [Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Valliant, John F. [Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, L8S 4M1 (Canada)], E-mail: valliant@mcmaster.ca

    2009-11-15

    Introduction: The aim of this work was to investigate the relative radiolabelling kinetics and affinity of a series of ligands for the [{sup 99m}Tc(CO){sub 3}]{sup +} core, both in the absence and in the presence of competing donors. This information was used to select a suitable ligand for radiolabelling complex peptide-based targeting vectors in high yield under mild conditions. Methods: A series of {alpha}-N-Fmoc-protected lysine derivatives bearing two heterocyclic donor groups at the {epsilon}-amine (, 2-pyridyl; , quinolyl; , 6-methoxy-2-pyridyl; 1d, 2-thiazolyl; 1e, N-methylimidazolyl; , 3-pyridyl) were synthesized and labelled with {sup 99m}Tc. A resin-capture purification strategy for the separation of residual ligand from the radiolabelled product was also developed. The binding affinities of targeted peptides 4, 5a and 5b for uPAR were determined using flow cytometry. Results: Variable temperature radiolabelling reactions using - and [{sup 99m}Tc(CO){sub 3}]{sup +} revealed optimal kinetics and good selectivity for compounds and 1d; in the case of , 1d, and 1e, the labelling can be conducted at ambient temperature. The utility of this class of ligands was further demonstrated by the radiolabelling of a cyclic peptide that is known to target the serine protease receptor uPAR; essentially quantitative incorporation of {sup 99m}Tc occurred exclusively at the SAAC site, despite the presence of a His residue, and without disruption of the disulfide bond. Conclusion: A series of single amino acid chelate (SAAC) ligands have been evaluated for their ability to incorporate {sup 99m}Tc into peptides. The lead agent to emerge from this work is the thiazole SAAC derivative 1d which has demonstrated the ability to regioselectively label the widest range of peptides.

  8. A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

    DEFF Research Database (Denmark)

    Klementiev, B; Novikova, T; Novitskaya, V

    2007-01-01

    death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

  9. Generation of functional HLA-DR*1101 tetramers receptive for loading with pathogen or tumour derived synthetic peptides

    Directory of Open Access Journals (Sweden)

    Protti Maria

    2005-12-01

    Full Text Available Abstract Background MHC class I-peptide tetramers are currently utilised to characterize CD8+ T cell responses at single cell level. The generation and use of MHC class II tetramers to study antigen-specific CD4+ T cells appears less straightforward. Most MHC class II tetramers are produced with a homogeneously built-in peptide, reducing greatly their flexibility of use. We attempted the generation of "empty" functional HLA-DR*1101 tetramers, receptive for loading with synthetic peptides by incubation. No such reagent is in fact available for this HLA-DR allele, one of the most frequent in the Caucasian population. Results We compared soluble MHC class II-immunoglobulin fusion proteins (HLA-DR*1101-Ig with soluble MHC class II protein fused with an optimised Bir site for enzymatic biotynilation (HLA-DR*1101-Bir, both produced in insect cells. The molecules were multimerised by binding fluorochrome-protein A or fluorochrome-streptavidin, respectively. We find that HLA-DR*1101-Bir molecules are superior to the HLA-DR*1101-Ig ones both in biochemical and functional terms. HLA-DR*1101-Bir molecules can be pulsed with at least three different promiscuous peptide epitopes, derived from Tetanus Toxoid, influenza HA and the tumour associated antigen MAGE-3 respectively, to stain specific CD4+ T cells. Both staining temperature and activation state of CD4+ T cells are critical for the binding of peptide-pulsed HLA-DR*1101-Bir to the cognate TCR. Conclusion It is therefore possible to generate a soluble recombinant HLA-DR*1101 backbone that is receptive for loading with different peptides to stain specific CD4+ T cells. As shown for other HLA-DR alleles, we confirm that not all the strategies to produce soluble HLA-DR*1101 multimers are equivalent.

  10. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  11. Rationale for the use of radiolabelled peptides in diagnosis and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Koopmans, K.P. [Martini Hospital, Department of Radiology and Nuclear Medicine, Groningen (Netherlands); Glaudemans, A.W.J.M. [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands)

    2012-02-15

    Nuclear medicine techniques are becoming more important in imaging oncological and infectious diseases. For metabolic imaging of these diseases, antibody and peptide imaging are currently used. In recent years peptide imaging has become important, therefore the rationale for the use of peptide imaging is described in this article. Criteria for a successful peptide tracer are a high target specificity, a high binding affinity, a long metabolic stability and a high target-to-background ratio. Tracer internalization is also beneficial. For oncological imaging, many tracers are available, most originating from regulatory peptides, but penetrating peptides are also being developed. Peptides for imaging inflammatory and infectious diseases include regulatory peptides, antimicrobial peptides and others. In conclusion, for the imaging of oncological, inflammatory and infectious diseases, many promising peptides are being developed. The ideal peptide probe is characterized by rapid and specific target localization and binding with a high tumour-to-background ratio. (orig.)

  12. Experimental myositis inducible with transfer of dendritic cells presenting a skeletal muscle C protein-derived CD8 epitope peptide.

    Science.gov (United States)

    Okiyama, Naoko; Hasegawa, Hisanori; Oida, Takatoku; Hirata, Shinya; Yokozeki, Hiroo; Fujimoto, Manabu; Miyasaka, Nobuyuki; Kohsaka, Hitoshi

    2015-07-01

    It is suggested that polymyositis, an autoimmune inflammatory myopathy, is mediated by autoaggressive CD8 T cells. Skeletal muscle C protein is a self-antigen that induces C protein-induced myositis, a murine model of polymyositis. To establish a new murine model of myositis inducible with a single CD8 T-cell epitope peptide that derives from the C protein, three internet-based prediction systems were employed to identify 24 candidate peptides of the immunogenic fragment of the C protein and bind theoretically to major histocompatibility complex class I molecules of C57BL/6 (B6) mice. RMA-S cell assay revealed that a HILIYSDV peptide, amino acid position 399-406 of the C protein, had the highest affinity to the H2-K(b) molecules. Transfer of mature bone marrow-derived dendritic cells pulsed with HILIYSDV induced myositis in naive B6 mice. This myositis was suppressed by anti-CD8-depleting antibodies but not by anti-CD4-depleting antibodies. Because this myositis model is mediated by CD8 T cells independently of CD4 T cells, it should be a useful tool to investigate pathology of polymyositis and develop therapies targeting CD8 T cells. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. The lactoferricin B-derived peptide, LfB17-34, induces melanogenesis in B16F10 cells.

    Science.gov (United States)

    Huang, Hsiu-Chin; Lin, Hsuan; Huang, Min-Chuan

    2017-03-01

    Lactoferricin B (LfcinB), a peptide of bovine lactoferrin (LfB), exhibits multiple biological functions, including antimicrobial, antiviral, antioxidant and immunomodulatory activities. However, the role of LfcinB-related peptides in melanogenesis remains unclear. In this study, a set of five LfcinB-related peptides was examined. We found that LfB17‑34, an 18-mer LfcinB-derived peptide, increased melanogenesis in B16F10 melanoma cells without significantly affecting cell viability. LfB17‑34 increased in vitro tyrosinase activity and melanin content in a dose-dependent manner. The results of RT-qPCR and western blot analyses showed that LfB17‑34 increased the mRNA and protein expression of tyrosinase and tyrosinase-related protein 1 (Trp1). Moreover, LfB17‑34 inhibited the phosphorylation of MAPK/Erk, but not p38 and Akt, and constitutively active MEK was able to reverse the LfB17-34-enhanced pigmentation, melanin content, and tyrosinase activity, suggesting a role of Erk signaling in the process of LfB17‑34-mediated pigmentation. Taken together, these results suggest that LfB17‑34 induces melanogenesis in B16F10 cells primarily through increased tyrosinase expression and activity and that LfB17‑34 could be further developed for the treatment of hypopigmentation disorders.

  14. Peptide-based biosensors: From self-assembled interfaces to molecular probes in electrochemical assays.

    Science.gov (United States)

    Puiu, Mihaela; Bala, Camelia

    2018-04-01

    Redox-tagged peptides have emerged as functional materials with multiple applications in the area of sensing and biosensing applications due to their high stability, excellent redox properties and versatility of biomolecular interactions. They allow direct observation of molecular interactions in a wide range of affinity and enzymatic assays and act as electron mediators. Short helical peptides possess the ability to self-assemble in specific configurations with the possibility to develop in highly-ordered, stable 1D, 2D and 3D architectures in a hierarchical controlled manner. We provide here a brief overview of the electrochemical techniques available to study the electron transfer in peptide films with particular interest in developing biosensors with immobilized peptide motifs, for biological and clinical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

    Directory of Open Access Journals (Sweden)

    Lohner Karl

    2008-11-01

    Full Text Available Abstract Background Growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (APs. These compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. Studies focused on the systematic characterization of APs are hampered by the lack of standard guidelines for testing these compounds. We investigated whether the information provided by methods commonly used for the biological characterization of APs is comparable, as it is often assumed. For this purpose, we determined the bacteriostatic, bactericidal, and permeability-increasing activity of synthetic peptides (n = 57; 9–13 amino acid residues in length analogous to the lipopolysaccharide-binding region of human lactoferricin by a number of the most frequently used methods and carried out a comparative analysis. Results While the minimum inhibitory concentration determined by an automated turbidimetry-based system (Bioscreen or by conventional broth microdilution methods did not differ significantly, bactericidal activity measured under static conditions in a low-ionic strength solvent resulted in a vast overestimation of antimicrobial activity. Under these conditions the degree of antagonism between the peptides and the divalent cations differed greatly depending on the bacterial strain tested. In contrast, the bioactivity of peptides was not affected by the type of plasticware (polypropylene vs. polystyrene. Susceptibility testing of APs using cation adjusted Mueller-Hinton was the most stringent screening method, although it may overlook potentially interesting peptides. Permeability assays based on sensitization to hydrophobic antibiotics provided overall information analogous – though not quantitatively comparable- to that of tests based on the uptake of hydrophobic fluorescent probes. Conclusion We demonstrate that subtle changes in methods for

  16. 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

  17. 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...

  18. Multifunctional gadolinium-based dendritic macromolecules as liver targeting imaging probes.

    Science.gov (United States)

    Luo, Kui; Liu, Gang; He, Bin; Wu, Yao; Gong, Qingyong; Song, Bin; Ai, Hua; Gu, Zhongwei

    2011-04-01

    The quest for highly efficient and safe contrast agents has become the key factor for successful application of magnetic resonance imaging (MRI). The gadolinium (Gd) based dendritic macromolecules, with precise and tunable nanoscopic sizes, are excellent candidates as multivalent MRI probes. In this paper, a novel series of Gd-based multifunctional peptide dendritic probes (generation 2, 3, and 4) possessing highly controlled structures and single molecular weight were designed and prepared as liver MRI probes. These macromolecular Gd-ligand agents exhibited up to 3-fold increase in T(1) relaxivity comparing to Gd-DTPA complexes. No obvious in vitro cytotoxicity was observed from the measured concentrations. These dendritic probes were further functionalized with multiple galactosyl moieties and led to much higher cell uptake in vitro as demonstrated in T(1)-weighted scans. During in vivo animal studies, the probes provided better signal intensity (SI) enhancement in mouse liver, especially at 60 min post-injection, with the most efficient enhancement from the galactosyl moiety decorated third generation dendrimer. The imaging results were verified with analysis of Gd content in liver tissues. The design strategy of multifunctional Gd-ligand peptide dendritic macromolecules in this study may be used for developing other sensitive MRI probes with targeting capability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. In vitro and in vivo cytotoxic activity of human lactoferricin derived antitumor peptide R-DIM-P-LF11-334 on human malignant melanoma.

    Science.gov (United States)

    Riedl, Sabrina; Rinner, Beate; Schaider, Helmut; Liegl-Atzwanger, Bernadette; Meditz, Katharina; Preishuber-Pflügl, Julia; Grissenberger, Sarah; Lohner, Karl; Zweytick, Dagmar

    2017-09-22

    Di-peptides derived from the human host defense peptide lactoferricin were previously described to specifically interact with the negatively charged lipid phosphatidylserine exposed by cancer cells. In this study one further derivative, namely R-DIM-P-LF11-334 is shown to exhibit even increased cancer toxicity in vitro and in vivo while non-neoplastic cells are not harmed. In liposomal model systems composed of phosphatidylserine mimicking cancerous and phosphatidylcholine mimicking non-cancerous membranes the specific interaction with the cancer marker PS was confirmed by specific induction of membrane perturbation and permeabilization in presence of the peptide. In vitro studies with cell lines of human malignant melanoma, such as A375, or primary cells of human melanoma metastases to the brain, as MUG Mel1, and non-neoplastic human dermal fibroblasts NHDF revealed high cytotoxic effect of R-DIM-P-LF11-334 on melanoma cells of A375 and MUG Mel1, whereas only minor effect on the dermal fibroblasts NHDF was observed, yielding an about 20-fold killing-specificity for A375 and MUG-Mel1. The LC 50 values for melanoma A375 and MUG Mel1 were about 10 μM. Analysis of secondary structure of the peptide revealed an increase in the proportion of β-sheets exclusively in presence of the cancer mimic. Stability studies further indicated a potential adequate stability in blood or under stringent conditions. Importantly the cytotoxic effect on cancer cells was also proven in vivo in mouse xenografts of human melanoma, where peptide treatment induced strong tumor regression and in average a tumor area reduction of 85% compared to tumors of control mice without peptide treatment.

  20. Bactericidal and antibiofilm activity of bactenecin-derivative peptides against the food-pathogen Listeria monocytogenes: New perspectives for food processing industry.

    Science.gov (United States)

    Palmieri, Gianna; Balestrieri, Marco; Capuano, Federico; Proroga, Yolande T R; Pomilio, Francesco; Centorame, Patrizia; Riccio, Alessia; Marrone, Raffaele; Anastasio, Aniello

    2018-08-20

    Antimicrobial peptides have received great attention for their potential benefits to extend the shelf-life of food-products. Innate defense regulator peptide-1018 (IDR-1018) represents a promising candidate for such applications, due to its broad-spectrum antimicrobial activity, although food-isolated pathogens have been poorly investigated. Herein, we describe the design and the structural-functional characterization of a new 1018-derivative peptide named 1018-K6, in which the alanine in position 6 was replaced with a lysine. Spectroscopic analysis revealed a noticeable switch from β-sheet to helical conformations of 1018-K6 respect to IDR-1018, with a faster folding kinetic and increased structural stability. Moreover, 1018-K6 evidenced a significant antibiofilm/bactericidal efficiency specifically against Listeria monocytogenes isolates from food-products and food-processing environments, belonging to serotype 4b involved in the majority of human-listeriosis cases, with EC 50 values two- five-fold lower than those measured for IDR-1018. Therefore, a single amino-acid substitution in IDR-1018 sequence produced severe changes in peptide conformation and antimicrobial performances. Published by Elsevier B.V.

  1. Spontaneous T-cell responses against peptides derived from the Taxol resistance-associated gene-3 (TRAG-3) protein in cancer patients

    DEFF Research Database (Denmark)

    Meier, Anders; Hadrup, Sine Reker; Svane, Inge Marie

    2005-01-01

    for immunotherapy of cancer. To identify HLA-A* 02.01 - restricted epitopes from TRAG-3, we screened cancer patients for spontaneous cytotoxic T-cell responses against TRAG-3 - derived peptides. The TRAG-3 protein sequence was screened for 9mer and 10mer peptides possessing HLA-A* 02.01 - binding motifs. Of 12......Expression of the cancer-testis antigen Taxol resistance - associated gene-3 (TRAG-3) protein is associated with acquired paclitaxel ( Taxol) resistance, and is expressed in various cancer types; e. g., breast cancer, leukemia, and melanoma. Thus, TRAG-3 represents an attractive target...... potential binders, 9 peptides were indeed capable of binding to the HLA-A* 02.01 molecule, with binding affinities ranging from strong to weak binders. Subsequently, lymphocytes from cancer patients ( 9 breast cancer patients, 12 melanoma patients, and 13 patients with hematopoietic malignancies) were...

  2. Probing the Gaseous Structure of a β-Hairpin Peptide with H/D Exchange and Electron Capture Dissociation.

    Science.gov (United States)

    Straus, Rita N; Jockusch, Rebecca A

    2017-02-01

    An improved understanding of the extent to which native protein structure is retained upon transfer to the gas phase promises to enhance biological mass spectrometry, potentially streamlining workflows and providing fundamental insights into hydration effects. Here, we investigate the gaseous conformation of a model β-hairpin peptide using gas-phase hydrogen-deuterium (H/D) exchange with subsequent electron capture dissociation (ECD). Global gas-phase H/D exchange levels, and residue-specific exchange levels derived from ECD data, are compared among the wild type 16-residue peptide GB1p and several variants. High protection from H/D exchange observed for GB1p, but not for a truncated version, is consistent with the retention of secondary structure of GB1p in the gas phase or its refolding into some other compact structure. Four alanine mutants that destabilize the hairpin in solution show levels of protection similar to that of GB1p, suggesting collapse or (re)folding of these peptides upon transfer to the gas phase. These results offer a starting point from which to understand how a key secondary structural element, the β-hairpin, is affected by transfer to the gas phase. This work also demonstrates the utility of a much-needed addition to the tool set that is currently available for the investigation of the gaseous conformation of biomolecules, which can be employed in the future to better characterize gaseous proteins and protein complexes. Graphical Abstract ᅟ.

  3. Marine Peptides and Their Anti-Infective Activities

    OpenAIRE

    Kang, Hee Kyoung; Seo, Chang Ho; Park, Yoonkyung

    2015-01-01

    Marine bioresources are a valuable source of bioactive compounds with industrial and nutraceutical potential. Numerous clinical trials evaluating novel chemotherapeutic agents derived from marine sources have revealed novel mechanisms of action. Recently, marine-derived bioactive peptides have attracted attention owing to their numerous beneficial effects. Moreover, several studies have reported that marine peptides exhibit various anti-infective activities, such as antimicrobial, antifungal,...

  4. Identification of Cyclin A Binders with a Fluorescent Peptide Sensor.

    Science.gov (United States)

    Pazos, Elena; Mascareñas, José L; Vázquez, M Eugenio

    2016-01-01

    A peptide sensor that integrates the 4-dimethylaminophthalimide (4-DMAP) fluorophore in a short cyclin A binding sequence displays a large fluorescence emission increase upon interacting with the cyclin A Binding Groove (CBG). Competitive displacement assays of this probe allow the straightforward identification of peptides that interact with the CBG, which could potentially block the recognition of CDK/cyclin A kinase substrates.

  5. Polyclonal cell activity of a repeat peptide derived from the sequence of an 85-kilodalton surface protein of Trypanosoma cruzi trypomastigotes.

    Science.gov (United States)

    Pestel, J; Defoort, J P; Gras-Masse, H; Afchain, D; Capron, A; Tartar, A; Ouaissi, A

    1992-01-01

    Some in vitro and in vivo biological activities of an octadecapeptide derived from an 85-kDa surface protein of Trypanosoma cruzi trypomastigote were studied. The peptide coupled to a carrier protein induced the proliferative response of lymph node cells from mice immunized with various antigens. Moreover, sera from mice immunized with the coupled peptide were found to contain antibodies against a number of self and nonself antigens: fibronectin, bovine serum albumin, myosin, tetanus toxoid, ovalbumin, keyhole limpet hemocyanin, and DNA. These results are discussed in the context of Chagas' disease immunopathology. PMID:1730508

  6. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte

    2013-01-01

    properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  7. Radioreceptor assay of opioid peptides in selected canine brain regions

    International Nuclear Information System (INIS)

    Desiderio, D.M.; Takeshita, H.

    1985-01-01

    A radioreceptor assay using the opioid delta receptor-preferring ligand D- 2 ala, D- 5 leu leucine enkephalin ( 3 H-DADL) and the broader-specificity ligand 3 H-etorphine was used to measure five HPLC-purified neuropeptide fractions derived from the peptide-rich fraction of tissue homogenates of nine anatomical regions of the canine brain. The receptoractive peptides studied were methionine enkephalin, alpha-neo-endorphin, dynorphin 1-8, methionine enkephalin-Arg-Phe, and leucine enkephalin. These peptides derive from two larger precursors: proenkephalin A, which contains methionine enkephalin, leucine enkephalin, methionine enkephalin-Arg-Phe; and proenkephalin B, which contains alpha-neo-endorphin and dynorphin 1-8. Receptoractive peptides were measured in the peptide-rich fraction derived from homogenates of canine hypothalamus, pituitary, caudate nucleus, amygdala, hippocampus, mid-brain, thalamus, pons-medulla, and cortex

  8. Prophylactic effects of elastin peptide derived from the bulbus arteriosus of fish on vascular dysfunction in spontaneously hypertensive rats.

    Science.gov (United States)

    Takemori, Kumiko; Yamamoto, Ei; Ito, Hiroyuki; Kometani, Takashi

    2015-01-01

    To determine the prophylactic effects of an elastin peptide derived from the bulbus arteriosus of bonitos and prolylglycine (PG), a degradation product of elastin peptide, on vascular dysfunction in spontaneously hypertensive rats (SHRs). Male 15-week-old SHR/Izm rats were fed without (control group) or with elastin peptide (1 g/kg body weight) for 5 weeks (EP group), or were infused via an osmotic mini-pump for 4 weeks with PG (PG group) or saline (control group). Using thoracic aortas, we assessed endothelial changes by scanning electron microscopy. Vascular reactivity (contraction and relaxation) and pressure-induced distension was compared. mRNA production levels of endothelial nitric oxide synthase (eNOS) and intercellular adhesion molecule-1 (ICAM-1) were investigated by real-time-polymerase chain reaction. Aortas of the EP group displayed limited endothelial damage compared with that in the control group. Under treatment of SHRs with elastin peptide, the effect of phenylephrine returned closer to the normal level observed in normotensive Wistar-Kyoto (WKY/Izm) rats. mRNA production of eNOS (but not ICAM-1) was greater in the EP group than in the control group. Endothelial damage was suppressed and pressure-induced vascular distension was greater in the PG group than in the corresponding control group. These results suggest that elastin peptide from bonitos elicits prophylactic affects hypertension-associated vascular dysfunction by targeting the eNOS signaling pathway. PG may be a key mediator of the beneficial effects of elastin peptide. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Antimicrobial beta-peptides and alpha-peptoids

    DEFF Research Database (Denmark)

    Godballe, Troels; Nilsson, Line L.; Petersen, Pernille D.

    2011-01-01

    candidates is derived from naturally occurring antimicrobial peptides. However, despite promising results in early-stage clinical trials, these molecules have faced some difficulties securing FDA approval, which can be linked to their poor metabolic stability. Hence, mimetics of these antimicrobial peptides...

  10. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Hancock, Robert E.W.; Jenssen, Håvard

    2010-01-01

    in antimicrobial activity. Consequently, the majority of peptides put into clinical trials have failed at some point, underlining the importance of a thorough peptide optimization. An important tool in peptide design and optimization is quantitative structure-activity relationship (QSAR) analysis, correlating...... chemical parameters with biological activities of the peptide, using statistical methods. In this review we will discuss two different in silico strategies of computer-aided antibacterial peptide design, a linear correlation model build as an extension of traditional principal component analysis (PCA......) and a non-linear artificial neural network model. Studies on structurally diverse peptides, have concluded that the PCA derived model are able to guide the antibacterial peptide design in a meaningful way, however requiring rather a high homology between the peptides in the test-set and the in silico...

  11. Synthesis of two tritium-labeled derivatives of a vasopressin antagonist peptide

    International Nuclear Information System (INIS)

    Landvatter, S.W.; Heys, J.R.

    1986-01-01

    SK and F 101926, a potent vasopressin antagonist, has been tritium labeled in the tyrosine residue via exchange followed by solid phase coupling to a hexapeptide. The peptide thus obtained was subsequently coupled with a PMP residue, cleaved from the resin with HF, oxidized by ferricyanide and purified by HPLC giving the desired cyclic peptide. Alternatively, a labeled PMP residue can be prepared via reduction starting from phenol. Conversion of the labeled cyclohexanone to PMP followed by solid phase coupling to a heptapeptide can then afford PMP labeled peptide. 3 refs

  12. Bleogens: Cactus-Derived Anti-Candida Cysteine-Rich Peptides with Three Different Precursor Arrangements

    Directory of Open Access Journals (Sweden)

    Shining Loo

    2017-12-01

    Full Text Available Cysteine-rich peptides (CRPs play important host-defense roles in plants. However, information concerning CRPs in the Cactaceae (cactus family is limited, with only a single cactus-derived CRP described to date. Here, we report the identification of 15 novel CRPs with three different precursor architectures, bleogens pB1-15 from Pereskia bleo of the Cactaceae family. By combining proteomic and transcriptomic methods, we showed that the prototype, bleogen pB1, contained 36 amino acid residues, a six-cysteine motif typical of the six-cysteine-hevein-like peptide (6C-HLP family, and a type I two-domain precursor consisting of an endoplasmic reticulum (ER and a mature domain. In contrast, the precursors of the other 14 bleogens contained a type II three-domain architecture with a propeptide domain inserted between the ER and the mature bleogen domain. Four of these 14 bleogens display a third type of architecture with a tandemly repeating bleogen domain. A search of the Onekp database revealed that <1% plant species possess three different precursor architectures for the biosynthesis of 6C-HLPs, including Lophophora williamsii, Pereskia aculeate, Portulaca cryptopetala, Portulaca oleracea, Portulaca suffruticosa, and Talinum sp. NMR analysis confirmed that bleogen pB1 has cystine-knot disulfide connectivity as well as a two-beta-sheet and a four-loop structural fold that is similar to other 6C-HLPs. Sequence analysis, structural studies, and in silico modeling revealed that bleogen pB1 has a cation-polar-cation motif, a signature heparin-binding motif that was confirmed by heparin affinity chromatography. Cell-based assays showed that bleogen pB1 is non-toxic to mammalian cells but functions as an anti-Candida peptide. Taken together, our findings provide insight into the occurrence, functions and precursor architectures of CRPs in the cactus family.

  13. Radioreceptor assay of opioid peptides in selected canine brain regions

    Energy Technology Data Exchange (ETDEWEB)

    Desiderio, D.M.; Takeshita, H.

    1985-09-01

    A radioreceptor assay using the opioid delta receptor-preferring ligand D-/sup 2/ala, D-/sup 5/leu leucine enkephalin (/sup 3/H-DADL) and the broader-specificity ligand /sup 3/H-etorphine was used to measure five HPLC-purified neuropeptide fractions derived from the peptide-rich fraction of tissue homogenates of nine anatomical regions of the canine brain. The receptoractive peptides studied were methionine enkephalin, alpha-neo-endorphin, dynorphin 1-8, methionine enkephalin-Arg-Phe, and leucine enkephalin. These peptides derive from two larger precursors: proenkephalin A, which contains methionine enkephalin, leucine enkephalin, methionine enkephalin-Arg-Phe; and proenkephalin B, which contains alpha-neo-endorphin and dynorphin 1-8. Receptoractive peptides were measured in the peptide-rich fraction derived from homogenates of canine hypothalamus, pituitary, caudate nucleus, amygdala, hippocampus, mid-brain, thalamus, pons-medulla, and cortex.

  14. 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

  15. Oxidation of free, peptide and protein tryptophan residues mediated by AAPH-derived free radicals: role of alkoxyl and peroxyl radicals

    DEFF Research Database (Denmark)

    Fuentes-Lemus, E.; Dorta, E.; Escobar, E.

    2016-01-01

    The oxidation of tryptophan (Trp) residues, mediated by peroxyl radicals (ROOc), follows a complex mechanism involving free radical intermediates, and short chain reactions. The reactivity of Trp towards ROOc should be strongly affected by its inclusion in peptides and proteins. To examine...... the latter, we investigated (by fluorescence) the kinetic of the consumption of free, peptide- and protein-Trp residues towards AAPH (2,20 -azobis(2-amidinopropane)dihydrochloride)-derived free radicals. Interestingly, the initial consumption rates (Ri ) were only slightly influenced by the inclusion of Trp...... concentrations (10–50 mM), the values of Ri were nearly constant; and at high Trp concentrations (50 mM to 1 mM), a slower increase of Ri than expected for chain reactions. Similar behavior was detected for all three systems (free Trp, and Trp in peptides and proteins). For the first time we are showing...

  16. Effects of atomic-level nano-structured hydroxyapatite on adsorption of bone morphogenetic protein-7 and its derived peptide by computer simulation.

    Science.gov (United States)

    Wang, Qun; Wang, Menghao; Lu, Xiong; Wang, Kefeng; Fang, Liming; Ren, Fuzeng; Lu, Guoming

    2017-11-09

    Hydroxyapatite (HA) is the principal inorganic component of bones and teeth and has been widely used as a bone repair material because of its good biocompatibility and bioactivity. Understanding the interactions between proteins and HA is crucial for designing biomaterials for bone regeneration. In this study, we evaluated the effects of atomic-level nano-structured HA (110) surfaces on the adsorption of bone morphogenetic protein-7 (BMP-7) and its derived peptide (KQLNALSVLYFDD) using molecular dynamics and density functional theory methods. The results indicated that the atomic-level morphology of HA significantly affected the interaction strength between proteins and HA substrates. The interactions of BMP-7 and its derived peptide with nano-concave and nano-pillar HA surfaces were stronger than those with flat or nano-groove HA surfaces. The results also revealed that if the groove size of nano-structured HA surfaces matched that of residues in the protein or peptide, these residues were likely to spread into the grooves of the nano-groove, nano-concave, and nano-pillar HA, further strengthening the interactions. These results are helpful in better understanding the adsorption behaviors of proteins onto nano-structured HA surfaces, and provide theoretical guidance for designing novel bioceramic materials for bone regeneration and tissue engineering.

  17. Ultrafast Screening of a Novel, Moderately Hydrophilic Angiotensin-Converting-Enzyme-Inhibitory Peptide, RYL, from Silkworm Pupa Using an Fe-Doped-Silkworm-Excrement-Derived Biocarbon: Waste Conversion by Waste.

    Science.gov (United States)

    Liu, Long; Wei, Yanan; Chang, Qing; Sun, Huaju; Chai, Kungang; Huang, Zuqiang; Zhao, Zhenxia; Zhao, Zhongxing

    2017-12-27

    A novel, moderately hydrophilic peptide (RYL) with high ACE-inhibitory activity was screened ultrafast via a concept of waste conversion using waste. This novel peptide was screened from silkworm pupa using an Fe-doped porous biocarbon (FL/Z-SE) derived from silkworm excrement. FL/Z-SE possessed magnetic properties and specific selection for peptides due to Fe's dual functions. The selected RYL, which has moderate hydrophilicity (LogP = -0.22), exhibited a comparatively high ACE-inhibitory activity (IC 50 = 3.31 ± 0.11 μM). The inhibitory kinetics and docking-simulation results show that, as a competitive ACE inhibitor, RYL formed five hydrogen bonds with the ACE residues in the S1 and S2 pockets. In this work, both the screening carbon material and the selected ACE-inhibitory peptide were derived from agricultural waste (silkworm excrement and pupa), which offers a new way of thinking about the development of advanced uses of the silkworm byproducts and wastes.

  18. Therapeutic Efficacy with Treatment-related Toxicities of 177Lu-labeled Bombesin Derivative for the Peptide Receptor Radiotherapy

    International Nuclear Information System (INIS)

    Lim, Jae Cheong; Cho, Eun Ha; Lee, So Young

    2015-01-01

    The gastrin-releasing peptide receptor (GRPR) has been shown to be overexpressed in many human tumours, including breast cancer, prostate cancer, small cell lung cancer, ovarian cancers, endometrial cancers, and gastrointestinal stromal tumors. In particular, GRPR expression is high in 83 % of invasive primary prostatic carcinomas. These results suggest that 177 Lu-labeled bombesin derivative has promising characteristics as a novel nuclear medicine, especially for the treatment of GRPR over-expressing prostate tumors

  19. Tidbits for the synthesis of bis(2-sulfanylethyl)amido (SEA) polystyrene resin, SEA peptides and peptide thioesters.

    Science.gov (United States)

    Ollivier, Nathalie; Raibaut, Laurent; Blanpain, Annick; Desmet, Rémi; Dheur, Julien; Mhidia, Reda; Boll, Emmanuelle; Drobecq, Hervé; Pira, Silvain L; Melnyk, Oleg

    2014-02-01

    Protein total chemical synthesis enables the atom-by-atom control of the protein structure and therefore has a great potential for studying protein function. Native chemical ligation of C-terminal peptide thioesters with N-terminal cysteinyl peptides and related methodologies are central to the field of protein total synthesis. Consequently, methods enabling the facile synthesis of peptide thioesters using Fmoc-SPPS are of great value. Herein, we provide a detailed protocol for the preparation of bis(2-sulfanylethyl)amino polystyrene resin as a starting point for the synthesis of C-terminal bis(2-sulfanylethyl)amido peptides and of peptide thioesters derived from 3-mercaptopropionic acid. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

  20. 2D-QSAR in hydroxamic acid derivatives as peptide deformylase inhibitors and antibacterial agents.

    Science.gov (United States)

    Gupta, Manish K; Mishra, Pradeep; Prathipati, Philip; Saxena, Anil K

    2002-12-01

    Peptide deformylase catalyzes the removal of N-formyl group from the N-formylmethionine of ribosome synthesized polypeptide in eubacteria. Quantitative structure-activity relationship (QSAR) studies have been carried out in a series of beta-sulfonyl and beta-sulfinyl hydroxamic acid derivatives for their PDF enzyme inhibitory and antibacterial activities against Escherichia coli DC2 and Moraxella catarrhalis RA21 which demonstrate that the PDF inhibitory activity in cell free and whole cell system increases with increase in molar refractivity and hydrophobicity. The comparison of the QSARs between the cell free and whole cell system indicate that the active binding sites in PDF isolated from E. coli and in M. catarrhalis RA21 are similar and the whole cell antibacterial activity is mainly due to the inhibition of PDF. Apart from this the QSARs on some matrixmetelloproteins (COL-1, COL-3, MAT and HME) and natural endopeptidase (NEP) indicate the possibilities of introducing selectivity in these hydroxamic acid derivatives for their PDF inhibitory activity.

  1. Maize Bioactive Peptides against Cancer

    Science.gov (United States)

    Díaz-Gómez, Jorge L.; Castorena-Torres, Fabiola; Preciado-Ortiz, Ricardo E.; García-Lara, Silverio

    2017-06-01

    Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derived food products has been associated with reduction risks of various types of cancer. Cereals main biomolecules includes proteins, peptides, and amino acids present in different quantities within the grain. The nutraceutical properties associated with peptides exerts biological functions that promote health and prevent this disease. In this review, we report the current status and advances on maize peptides regarding bioactive properties that have been reported such as antioxidant, antihypertensive, hepatoprotective, and anti-tumour activities. We also highlighted its biological potential through which maize bioactive peptides exert anti-cancer activity. Finally, we analyse and emphasize the possible areas of application for maize peptides.

  2. Probing peptide fragment ion structures by combining sustained off-resonance collision-induced dissociation and gas-phase H/D exchange (SORI-HDX) in Fourier transform ion-cyclotron resonance (FT-ICR) instruments.

    Science.gov (United States)

    Somogyi, Arpád

    2008-12-01

    The usefulness of gas-phase H/D exchange is demonstrated to probe heterogeneous fragment and parent ion populations. Singly and multiply protonated peptides/proteins were fragmented by using sustained off-resonance irradiation collision-induced dissociation (SORI-CID). The fragments and the surviving precursor ions then all undergo H/D exchange in the gas-phase with either D(2)O or CD(3)OD under the same experimental conditions. Usually, 10 to 60 s of reaction time is adequate to monitor characteristic differences in the H/D exchange kinetic rates. These differences are then correlated to isomeric ion structures. The SORI-HDX method can be used to rapidly test fragment ion structures and provides useful insights into peptide fragmentation mechanisms.

  3. Soluble elastin peptides in cardiovascular homeostasis: Foe or ally.

    Science.gov (United States)

    Qin, Zhenyu

    2015-05-01

    Elastin peptides, also known as elastin-derived peptides or elastokines, are soluble polypeptides in blood and tissue. The blood levels of elastin peptides are usually low but can increase during cardiovascular diseases, such as atherosclerosis, aortic aneurysm and diabetes with vascular complications. Generally, elastin peptides are derived from the degradation of insoluble elastic polymers. The biological activities of elastin peptides are bidirectional, e.g., a pro-inflammatory effect on monocyte migration induction vs. a protective effect on vasodilation promotion. However, recent in vivo studies have demonstrated that elastin peptides promote the formation of atherosclerotic plaques in hypercholesterolemic mice and induce hyperglycemia and elevations in plasma lipid levels in fasted mice. More important, the detrimental effects induced by elastin peptides can be largely inhibited by genetic or pharmacological blockade of the elastin receptor complex or by neutralization of an antibody against elastin peptides. These studies indicate new therapeutic strategies for the treatment of cardiovascular diseases by targeting elastin peptide metabolism. Therefore, the goal of this review is to summarize current knowledge about elastin peptides relevant to cardiovascular pathologies to further delineate their potential application in cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Regional differences in the expression of brain-derived neurotrophic factor (BDNF) pro-peptide, proBDNF and preproBDNF in the brain confer stress resilience.

    Science.gov (United States)

    Yang, Bangkun; Yang, Chun; Ren, Qian; Zhang, Ji-Chun; Chen, Qian-Xue; Shirayama, Yukihiko; Hashimoto, Kenji

    2016-12-01

    Using learned helplessness (LH) model of depression, we measured protein expression of brain-derived neurotrophic factor (BDNF) pro-peptide, BDNF precursors (proBDNF and preproBDNF) in the brain regions of LH (susceptible) and non-LH rats (resilience). Expression of preproBDNF, proBDNF and BDNF pro-peptide in the medial prefrontal cortex of LH rats, but not non-LH rats, was significantly higher than control rats, although expression of these proteins in the nucleus accumbens of LH rats was significantly lower than control rats. This study suggests that regional differences in conversion of BDNF precursors into BDNF and BDNF pro-peptide by proteolytic cleavage may contribute to stress resilience.

  5. Ligand-regulated peptides: a general approach for modulating protein-peptide interactions with small molecules.

    Science.gov (United States)

    Binkowski, Brock F; Miller, Russell A; Belshaw, Peter J

    2005-07-01

    We engineered a novel ligand-regulated peptide (LiRP) system where the binding activity of intracellular peptides is controlled by a cell-permeable small molecule. In the absence of ligand, peptides expressed as fusions in an FKBP-peptide-FRB-GST LiRP scaffold protein are free to interact with target proteins. In the presence of the ligand rapamycin, or the nonimmunosuppressive rapamycin derivative AP23102, the scaffold protein undergoes a conformational change that prevents the interaction of the peptide with the target protein. The modular design of the scaffold enables the creation of LiRPs through rational design or selection from combinatorial peptide libraries. Using these methods, we identified LiRPs that interact with three independent targets: retinoblastoma protein, c-Src, and the AMP-activated protein kinase. The LiRP system should provide a general method to temporally and spatially regulate protein function in cells and organisms.

  6. Liposomes bi-functionalized with phosphatidic acid and an ApoE-derived peptide affect Aβ aggregation features and cross the blood-brain-barrier: implications for therapy of Alzheimer disease

    NARCIS (Netherlands)

    Bana, Laura; Minniti, Stefania; Salvati, Elisa; Sesana, Silvia; Zambelli, Vanessa; Cagnotto, Alfredo; Orlando, Antonina; Cazzaniga, Emanuela; Zwart, Rob; Scheper, Wiep; Masserini, Massimo; Re, Francesca

    2014-01-01

    Targeting amyloid-β peptide (Aβ) within the brain is a strategy actively sought for therapy of Alzheimer's disease (AD). We investigated the ability of liposomes bi-functionalized with phosphatidic acid and with a modified ApoE-derived peptide (mApoE-PA-LIP) to affect Aβ aggregation/disaggregation

  7. Structural basis for the enhanced activity of cyclic antimicrobial peptides : The case of BPC194

    NARCIS (Netherlands)

    Mika, Jacek T.; Moiset, Gemma; Cirac, Anna D.; Feliu, Lidia; Bardaji, Eduard; Planas, Marta; Sengupta, Durba; Marrink, Siewert J.; Poolman, Bert

    We report the molecular basis for the differences in activity of cyclic and linear antimicrobial peptides. We iteratively performed atomistic molecular dynamics simulations and biophysical measurements to probe the interaction of a cyclic antimicrobial peptide and its inactive linear analogue with

  8. Fluorescent Protein Voltage Probes Derived from ArcLight that Respond to Membrane Voltage Changes with Fast Kinetics

    Science.gov (United States)

    Han, Zhou; Jin, Lei; Platisa, Jelena; Cohen, Lawrence B.; Baker, Bradley J.; Pieribone, Vincent A.

    2013-01-01

    We previously reported the discovery of a fluorescent protein voltage probe, ArcLight, and its derivatives that exhibit large changes in fluorescence intensity in response to changes of plasma membrane voltage. ArcLight allows the reliable detection of single action potentials and sub-threshold activities in individual neurons and dendrites. The response kinetics of ArcLight (τ1-on ~10 ms, τ2-on ~ 50 ms) are comparable with most published genetically-encoded voltage probes. However, probes using voltage-sensing domains other than that from the Ciona intestinalis voltage sensitive phosphatase exhibit faster kinetics. Here we report new versions of ArcLight, in which the Ciona voltage-sensing domain was replaced with those from chicken, zebrafish, frog, mouse or human. We found that the chicken and zebrafish-based ArcLight exhibit faster kinetics, with a time constant (τ) less than 6ms for a 100 mV depolarization. Although the response amplitude of these two probes (8-9%) is not as large as the Ciona-based ArcLight (~35%), they are better at reporting action potentials from cultured neurons at higher frequency. In contrast, probes based on frog, mouse and human voltage sensing domains were either slower than the Ciona-based ArcLight or had very small signals. PMID:24312287

  9. Fluorescent protein voltage probes derived from ArcLight that respond to membrane voltage changes with fast kinetics.

    Directory of Open Access Journals (Sweden)

    Zhou Han

    Full Text Available We previously reported the discovery of a fluorescent protein voltage probe, ArcLight, and its derivatives that exhibit large changes in fluorescence intensity in response to changes of plasma membrane voltage. ArcLight allows the reliable detection of single action potentials and sub-threshold activities in individual neurons and dendrites. The response kinetics of ArcLight (τ1-on ~10 ms, τ2-on ~ 50 ms are comparable with most published genetically-encoded voltage probes. However, probes using voltage-sensing domains other than that from the Ciona intestinalis voltage sensitive phosphatase exhibit faster kinetics. Here we report new versions of ArcLight, in which the Ciona voltage-sensing domain was replaced with those from chicken, zebrafish, frog, mouse or human. We found that the chicken and zebrafish-based ArcLight exhibit faster kinetics, with a time constant (τ less than 6 ms for a 100 mV depolarization. Although the response amplitude of these two probes (8-9% is not as large as the Ciona-based ArcLight (~35%, they are better at reporting action potentials from cultured neurons at higher frequency. In contrast, probes based on frog, mouse and human voltage sensing domains were either slower than the Ciona-based ArcLight or had very small signals.

  10. N-acylated peptides derived from human lactoferricin perturb organization of cardiolipin and phosphatidylethanolamine in cell membranes and induce defects in Escherichia coli cell division.

    Directory of Open Access Journals (Sweden)

    Dagmar Zweytick

    Full Text Available Two types of recently described antibacterial peptides derived from human lactoferricin, either nonacylated or N-acylated, were studied for their different interaction with membranes of Escherichia coli in vivo and in model systems. Electron microscopy revealed striking effects on the bacterial membrane as both peptide types induced formation of large membrane blebs. Electron and fluorescence microscopy, however demonstrated that only the N-acylated peptides partially induced the generation of oversized cells, which might reflect defects in cell-division. Further a different distribution of cardiolipin domains on the E. coli membrane was shown only in the presence of the N-acylated peptides. The lipid was distributed over the whole bacterial cell surface, whereas cardiolipin in untreated and nonacylated peptide-treated cells was mainly located at the septum and poles. Studies with bacterial membrane mimics, such as cardiolipin or phosphatidylethanolamine revealed that both types of peptides interacted with the negatively charged lipid cardiolipin. The nonacylated peptides however induced segregation of cardiolipin into peptide-enriched and peptide-poor lipid domains, while the N-acylated peptides promoted formation of many small heterogeneous domains. Only N-acylated peptides caused additional severe effects on the main phase transition of liposomes composed of pure phosphatidylethanolamine, while both peptide types inhibited the lamellar to hexagonal phase transition. Lipid mixtures of phosphatidylethanolamine and cardiolipin revealed anionic clustering by all peptide types. However additional strong perturbation of the neutral lipids was only seen with the N-acylated peptides. Nuclear magnetic resonance demonstrated different conformational arrangement of the N-acylated peptide in anionic and zwitterionic micelles revealing possible mechanistic differences in their action on different membrane lipids. We hypothesized that both peptides kill

  11. TRAM-Derived Decoy Peptides inhibits the inflammatory response in mouse mammary epithelial cells and a mastitis model in mice.

    Science.gov (United States)

    Hu, Xiaoyu; Tian, Yuan; Wang, Tiancheng; Zhang, Wenlong; Wang, Wei; Gao, Xuejiao; Qu, Shihui; Cao, Yongguo; Zhang, Naisheng

    2015-10-05

    It has been proved that TRAM-Derived Decoy peptides have anti-inflammatory properties. In this study, we synthesized a TRAM-Derived decoy peptide (TM6), belongs to TRAM TIR domain, of which sequence is "N"-RQIKIWFQNRRMKWK, KENFLRDTWCNFQFY-"C" and evaluated the effects of TM6 on lipopolysaccharide-induced mastitis in mice. In vivo, LPS-induced mice mastitis model was established by injection of LPS through the duct of mammary gland. TM6 was injected 1h before or after LPS treatment. In vitro, primary mouse mammary epithelial cells were used to investigate the effects of TM6 on LPS-induced inflammatory responses. The results showed that TM6 inhibited LPS-induced mammary gland histopathologic changes, MPO activity, and TNF-α, IL-1β and IL-6 production in mice. In vitro, TM6 significantly inhibited LPS-induced TNF-α and IL-6 production, as well as NF-κB and MAPKs activation. In conclusion, this study demonstrated that TM6 had protective effects on LPS-mastitis and may be a promising therapeutic reagent for mastitis treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Antioxidant Activity of Purified Active Peptide Derived from Spirulina platensis Enzymatic Hydrolysates

    OpenAIRE

    Nur Maulida Safitri; Endang Yuli Herawati; Jue Liang Hsu

    2017-01-01

    The aim of this study is to isolate the antioxidative peptide from Spirulina platensis. Peptide was obtained by proteolytic digestion, ultrafiltration, fractionation by RP-HPLC, identified by LC-MS/MS—MASCOT Distiller and measured its antioxidant activity by DPPH (2.2-Diphenyl-1-picrylhydrazyl) assay. Results showed that thermolysin was the most effective enzyme to digest this algae. The active peptide Phe-Ser-Glu-Ser-Ser-Ala-Pro-Glu-Gln-His-Tyr (m/z 1281.51) was identified and synthetized, w...

  13. Impact of peptide clustering on unbinding forces in the context of fusion mimetics

    International Nuclear Information System (INIS)

    Pähler, Gesa; Lorenz, Bärbel; Janshoff, Andreas

    2013-01-01

    Highlights: ► Coiled-coil peptides as SNARE mimetics for membrane fusion. ► Interaction forces assessed by colloidal probe microscopy. ► Lateral organization of lipopeptides visualized by atomic force microscopy. -- Abstract: Coiled-coil zipping and unzipping is a pivotal process in SNARE-regulated membrane fusion. In this study we examine this process mediated by a minimal model for coiled-coil formation employing force spectroscopy in the context of membrane-coated surfaces and probes. The interaction forces of several hundred pN are surprisingly low considering the proposed amount of molecular bonds in the contact zone. However, by means of high-resolution imaging employing atomic force microscopy and studying the lateral mobility of lipids and peptides as a function of coiled-coil formation, we are able to supply a detailed view on processes occurring on the membrane surfaces during force measurements. The interaction forces determined here are not only dependent on the peptide concentration on the surface, but also on the regional organization of lateral peptide clusters found prior to coiled-coil formation

  14. Protein-based stable isotope probing.

    Science.gov (United States)

    Jehmlich, Nico; Schmidt, Frank; Taubert, Martin; Seifert, Jana; Bastida, Felipe; von Bergen, Martin; Richnow, Hans-Hermann; Vogt, Carsten

    2010-12-01

    We describe a stable isotope probing (SIP) technique that was developed to link microbe-specific metabolic function to phylogenetic information. Carbon ((13)C)- or nitrogen ((15)N)-labeled substrates (typically with >98% heavy label) were used in cultivation experiments and the heavy isotope incorporation into proteins (protein-SIP) on growth was determined. The amount of incorporation provides a measure for assimilation of a substrate, and the sequence information from peptide analysis obtained by mass spectrometry delivers phylogenetic information about the microorganisms responsible for the metabolism of the particular substrate. In this article, we provide guidelines for incubating microbial cultures with labeled substrates and a protocol for protein-SIP. The protocol guides readers through the proteomics pipeline, including protein extraction, gel-free and gel-based protein separation, the subsequent mass spectrometric analysis of peptides and the calculation of the incorporation of stable isotopes into peptides. Extraction of proteins and the mass fingerprint measurements of unlabeled and labeled fractions can be performed in 2-3 d.

  15. Label-Free Fluorescent Detection of Trypsin Activity Based on DNA-Stabilized Silver Nanocluster-Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Cai-Xia Zhuo

    2016-11-01

    Full Text Available Trypsin is important during the regulation of pancreatic exocrine function. The detection of trypsin activity is currently limited because of the need for the substrate to be labeled with a fluorescent tag. A label-free fluorescent method has been developed to monitor trypsin activity. The designed peptide probe consists of six arginine molecules and a cysteine terminus and can be conjugated to DNA-stabilized silver nanoclusters (DNA-AgNCs by Ag-S bonding to enhance fluorescence. The peptide probe can also be adsorbed to the surface of graphene oxide (GO, thus resulting in the fluorescence quenching of DNA-AgNCs-peptide conjugate because of Förster resonance energy transfer. Once trypsin had degraded the peptide probe into amino acid residues, the DNA-AgNCs were released from the surface of GO, and the enhanced fluorescence of DNA-AgNCs was restored. Trypsin can be determined with a linear range of 0.0–50.0 ng/mL with a concentration as low as 1 ng/mL. This label-free method is simple and sensitive and has been successfully used for the determination of trypsin in serum. The method can also be modified to detect other proteases.

  16. Matrix- and plasma-derived peptides promote tissue-specific injury responses and wound healing in diabetic swine.

    Science.gov (United States)

    Sheets, Anthony R; Massey, Conner J; Cronk, Stephen M; Iafrati, Mark D; Herman, Ira M

    2016-07-02

    Non-healing wounds are a major global health concern and account for the majority of non-traumatic limb amputations worldwide. However, compared to standard care practices, few advanced therapeutics effectively resolve these injuries stemming from cardiovascular disease, aging, and diabetes-related vasculopathies. While matrix turnover is disrupted in these injuries, debriding enzymes may promote healing by releasing matrix fragments that induce cell migration, proliferation, and morphogenesis, and plasma products may also stimulate these processes. Thus, we created matrix- and plasma-derived peptides, Comb1 and UN3, which induce cellular injury responses in vitro, and accelerate healing in rodent models of non-healing wounds. However, the effects of these peptides in non-healing wounds in diabetes are not known. Here, we interrogated whether these peptides stimulate healing in a diabetic porcine model highly reminiscent of human healing impairments in type 1 and type 2-diabetes. After 3-6 weeks of streptozotocin-induced diabetes, full-thickness wounds were surgically created on the backs of adult female Yorkshire swine under general anesthesia. Comb1 and UN3 peptides or sterile saline (negative control) were administered to wounds daily for 3-7 days. Following sacrifice, wound tissues were harvested, and quantitative histological and immunohistochemical analyses were performed for wound closure, angiogenesis and granulation tissue deposition, along with quantitative molecular analyses of factors critical for angiogenesis, epithelialization, and dermal matrix remodeling. Comb1 and UN3 significantly increase re-epithelialization and angiogenesis in diabetic porcine wounds, compared to saline-treated controls. Additionally, fluorescein-conjugated Comb1 labels keratinocytes, fibroblasts, and vascular endothelial cells in porcine wounds, and Far western blotting reveals these cell populations express multiple fluorescein-Comb1-interacting proteins in vitro. Further

  17. A convenient colorimetric and ratiometric fluorescent probe for detection of cyanide based on BODIPY derivative in aqueous media

    Directory of Open Access Journals (Sweden)

    Yanhua Yu

    2017-06-01

    Full Text Available A convenient colorimetric and ratiometric fluorescent probe based on BODIPY derivative for cyanide detection has been synthesized, whose structural contains a dicyanovinyl group used as a sensing unit. Among the tested analytes, such as CN−, F−, Cl−, Br−, I−, ClO4−, AcO−, NO3−, H2PO4− HSO4−, S2− and N3−, only CN− could react with dicyanovinyl moiety by nucleophilic addition, which disrupted the π-conjugation of the probe and hindered the intramolecular charge transfer (ICT, leading a blue shift of absorption and fluorescence spectrum and a concomitant color change from yellow to light pink. The detection limit of this probe was calculated to be 0.98 μM, which is lower than the maximum concentration in drinking water (1.9 μM permitted by the World Health Organization (WHO. Moreover, the probe showed excellent selectivity and anti-interference ability towards CN− over other anions. The reaction mechanism was fully supported by 1H NMR and MS spectrum.

  18. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth

    2014-01-01

    Natriuretic peptides have emerged as important diagnostic and prognostic tools for cardiovascular disease. Plasma measurement of the bioactive peptides as well as precursor-derived fragments is a sensitive tool in assessing heart failure. In heart failure, the peptides are used as treatment...... in decompensated disease. In contrast, their biological effects on the cerebral hemodynamics are poorly understood. In this mini-review, we summarize the hemodynamic effects of the natriuretic peptides with a focus on the cerebral hemodynamics. In addition, we will discuss its potential implications in diseases...... where alteration of the cerebral hemodynamics plays a role such as migraine and acute brain injury including stroke. We conclude that a possible role of the peptides is feasible as evaluated from animal and in vitro studies, but more research is needed in humans to determine the precise response...

  19. Interaction of 18-residue peptides derived from amphipathic helical ...

    Indian Academy of Sciences (India)

    Madhsudhan

    interaction of proteins and peptides with membranes (Segrest ... favour surface activity have been described by Eisenberg et ... amphipathicity and propensity for α-helical conformation ..... Membrane destabilisation occurs due to electrostatic.

  20. 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,...

  1. Cooperative effects in differentiation and proliferation between PDGF-BB and matrix derived synthetic peptides in human osteoblasts

    Directory of Open Access Journals (Sweden)

    Vordemvenne Thomas

    2011-11-01

    Full Text Available Abstract Background Enhancing osteogenic capabilities of bone matrix for the treatment of fractures and segmental defects using growth factors is an active area of research. Recently, synthetic peptides like AC- 100, TP508 or p-15 corresponding to biologically active sequences of matrix proteins have been proven to stimulate bone formation. The platelet-derived growth factor (PDGF BB has been identified as an important paracrine factor in early bone healing. We hypothesized that the combined use of PDGF-BB with synthetic peptides could result in an increase in proliferation and calcification of osteoblast-like cells. Methods Osteoblast-like cell cultures were treated with PDGF and synthetic peptides, singly and as combinations, and compared to non-treated control cell cultures. The cultures were evaluated at days 2, 5, and 10 in terms of cell proliferation, calcification and gene expression of alkaline phosphate, collagen I and osteocalcin. Results Experimental findings revealed that the addition of PDGF, p-15 and TP508 and combinations of PDGF/AC-100, PDGF/p-15 and PDGF/TP508 resulted in an increase in proliferating osteoblasts, especially in the first 5 days of cultivation. Proliferation did not significantly differ between single factors and factor combinations (p > 0.05. The onset of calcification in osteoblasts occurred earlier and was more distinct compared to the corresponding control or PDGF stimulation alone. Significant difference was found for the combined use of PDGF/p-15 and PDGF/AC-100 (p Conclusions Our findings indicate that PDGF exhibits cooperative effects with synthetic peptides in differentiation and proliferation. These cooperative effects cause a significant early calcification of osteoblast-like cells (p

  2. Near-Infrared Optical Imaging of Ovarian Cancer Xenografts with Novel α3-Integrin Binding Peptide “OA02”

    Directory of Open Access Journals (Sweden)

    Olulanu H. Aina

    2005-10-01

    Full Text Available Through screening of random one-bead one-compound (OBOC libraries, we previously identified cyclic peptides with the cDGXGXXc motif that bind to α3 integrin subunit on ovarian adenocarcinoma cell lines ES-2, SKOV-3, and CaOV-3. We subsequently synthesized two secondary libraries based on this motif and identified new peptides that bound with a higher affinity to these cell lines. One of the peptides identified from the 20% “down-substituted” focused library was the cdG-HCit-GPQc (“OA02” peptide. The goal of this study was to determine whether this peptide labeled with near-infrared probes could be detected after intravenous injection in ovarian tumor-bearing mice and if it would selectively localize in the tumor. Three different forms of this peptide were synthesized, “OA02”-biotin (noncovalently linked to streptavidin-Cy5.5; “OA02”-Cy5.5 and “OA02”-AlexaFluo 680. Using a KODAK IS2000MM image station, these peptide probes were used at the near-infrared (NIR spectra to image nude mice bearing ES-2 (α3 integrin positive and Raji (α3 integrin negative xenografts. The peptide probe displayed highly specific tumor uptake within 15 min, which lasted for 70 min for “OA02”-Cy5.5 and “OA02”-AlexaFluo 680 and for 24 hours for “OA02”-biotin-streptavidin-Cy5.5. Some kidney and bladder signal were noted. Prior injection with anti-α3 monoclonal antibody blocked the binding of this peptide to the ES-2 tumors.

  3. Theory of Langmuir probes in anisotropic plasmas

    International Nuclear Information System (INIS)

    Sudit, I.D.; Woods, R.C.

    1994-01-01

    A theory has been developed for electron retardation by Langmuir probes of several geometries in a general anisotropic plasma with arbitrary probe orientation and valid for any sheath thickness. Electron densities and electron velocity distribution functions (EVDFs) are obtained from the second derivative of probe I-V curves, as in Druyvesteyn's original method, which was developed for isotropic plasmas. Fedorov had extended the latter method in the context of a thin sheath approximation, to axisymmetric plasmas, in which the EVDF is expanded in a series of Legendary polynomials. In the present work an expansion in a series of spherical harmonics is employed, and the coordinate transformations are handled using the irreducible representation of the three dimensional rotation group. It is shown that the Volterra integral equations that must be solved to obtain the expansion coefficients of the EVDF from the second derivative data are no more complicated in the general case that hose for the axisymmetric plasma. Furthermore in the latter case the results can be shown to be equivalent to Fedrov's thin sheath expression. For the case of planar probes a formulation based on first derivatives of the I-V curves has been obtained. If data is obtained at enough different probe orientation of a one sided planar disc probe, any number of spherical harmonic coefficient functions may be obtained by inverting a set of linear equations and the complete EVDF deduced. For a cylindrical probe or a two-sided planar disc probe the integration of the second derivative of the probe current gives the exact electron density with any arbitrary probe orientation and any degree of plasma anisotropy

  4. Supramolecular domains in mixed peptide self-assembled monolayers on gold nanoparticles.

    Science.gov (United States)

    Duchesne, Laurence; Wells, Geoff; Fernig, David G; Harris, Sarah A; Lévy, Raphaël

    2008-09-01

    Self-organization in mixed self-assembled monolayers of small molecules provides a route towards nanoparticles with complex molecular structures. Inspired by structural biology, a strategy based on chemical cross-linking is introduced to probe proximity between functional peptides embedded in a mixed self-assembled monolayer at the surface of a nanoparticle. The physical basis of the proximity measurement is a transition from intramolecular to intermolecular cross-linking as the functional peptides get closer. Experimental investigations of a binary peptide self-assembled monolayer show that this transition happens at an extremely low molar ratio of the functional versus matrix peptide. Molecular dynamics simulations of the peptide self-assembled monolayer are used to calculate the volume explored by the reactive groups. Comparison of the experimental results with a probabilistic model demonstrates that the peptides are not randomly distributed at the surface of the nanoparticle, but rather self-organize into supramolecular domains.

  5. Marine Peptides and Their Anti-Infective Activities

    Directory of Open Access Journals (Sweden)

    Hee Kyoung Kang

    2015-01-01

    Full Text Available Marine bioresources are a valuable source of bioactive compounds with industrial and nutraceutical potential. Numerous clinical trials evaluating novel chemotherapeutic agents derived from marine sources have revealed novel mechanisms of action. Recently, marine-derived bioactive peptides have attracted attention owing to their numerous beneficial effects. Moreover, several studies have reported that marine peptides exhibit various anti-infective activities, such as antimicrobial, antifungal, antimalarial, antiprotozoal, anti-tuberculosis, and antiviral activities. In the last several decades, studies of marine plants, animals, and microbes have revealed tremendous number of structurally diverse and bioactive secondary metabolites. However, the treatments available for many infectious diseases caused by bacteria, fungi, and viruses are limited. Thus, the identification of novel antimicrobial peptides should be continued, and all possible strategies should be explored. In this review, we will present the structures and anti-infective activity of peptides isolated from marine sources (sponges, algae, bacteria, fungi and fish from 2006 to the present.

  6. Cyclic peptide therapeutics: past, present and future.

    Science.gov (United States)

    Zorzi, Alessandro; Deyle, Kaycie; Heinis, Christian

    2017-06-01

    Cyclic peptides combine several favorable properties such as good binding affinity, target selectivity and low toxicity that make them an attractive modality for the development of therapeutics. Over 40 cyclic peptide drugs are currently in clinical use and around one new cyclic peptide drug enters the market every year on average. The vast majority of clinically approved cyclic peptides are derived from natural products, such as antimicrobials or human peptide hormones. New powerful techniques based on rational design and in vitro evolution have enabled the de novo development of cyclic peptide ligands to targets for which nature does not offer solutions. A look at the cyclic peptides currently under clinical evaluation shows that several have been developed using such techniques. This new source for cyclic peptide ligands introduces a freshness to the field, and it is likely that de novo developed cyclic peptides will be in clinical use in the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Identification of human embryonic progenitor cell targeting peptides using phage display.

    Directory of Open Access Journals (Sweden)

    Paola A Bignone

    Full Text Available Human pluripotent stem (hPS cells are capable of differentiation into derivatives of all three primary embryonic germ layers and can self-renew indefinitely. They therefore offer a potentially scalable source of replacement cells to treat a variety of degenerative diseases. The ability to reprogram adult cells to induced pluripotent stem (iPS cells has now enabled the possibility of patient-specific hPS cells as a source of cells for disease modeling, drug discovery, and potentially, cell replacement therapies. While reprogramming technology has dramatically increased the availability of normal and diseased hPS cell lines for basic research, a major bottleneck is the critical unmet need for more efficient methods of deriving well-defined cell populations from hPS cells. Phage display is a powerful method for selecting affinity ligands that could be used for identifying and potentially purifying a variety of cell types derived from hPS cells. However, identification of specific progenitor cell-binding peptides using phage display may be hindered by the large cellular heterogeneity present in differentiating hPS cell populations. We therefore tested the hypothesis that peptides selected for their ability to bind a clonal cell line derived from hPS cells would bind early progenitor cell types emerging from differentiating hPS cells. The human embryonic stem (hES cell-derived embryonic progenitor cell line, W10, was used and cell-targeting peptides were identified. Competition studies demonstrated specificity of peptide binding to the target cell surface. Efficient peptide targeted cell labeling was accomplished using multivalent peptide-quantum dot complexes as detected by fluorescence microscopy and flow cytometry. The cell-binding peptides were selective for differentiated hPS cells, had little or no binding on pluripotent cells, but preferential binding to certain embryonic progenitor cell lines and early endodermal hPS cell derivatives. Taken

  9. Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r.

    Science.gov (United States)

    Björn, Camilla; Mahlapuu, Margit; Mattsby-Baltzer, Inger; Håkansson, Joakim

    2016-07-01

    Antimicrobial peptides (AMPs) have emerged as a new class of drug candidates for the treatment of infectious diseases. Here we describe a novel AMP, HLR1r, which is structurally derived from the human milk protein lactoferrin and demonstrates a broad spectrum microbicidal action in vitro. The minimum concentration of HLR1r needed for killing ≥99% of microorganisms in vitro, was in the range of 3-50μg/ml for common Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and for the yeast Candida albicans, when assessed in diluted brain-heart infusion medium. We found that HLR1r also possesses anti-inflammatory properties as evidenced by inhibition of tumor necrosis factor alpha (TNF-α) secretion from human monocyte-derived macrophages and by repression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) secretion from human mesothelial cells, without any cytotoxic effect observed at the concentration range tested (up to 400μg/ml). HLR1r demonstrated pronounced anti-infectious effect in in vivo experimental models of cutaneous candidiasis in mice and of excision wounds infected with MRSA in rats as well as in an ex vivo model of pig skin infected with S. aureus. In conclusion, HLR1r may constitute a new therapeutic alternative for local treatment of skin infections. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Food matrix interaction and bioavailability of bioactive peptides

    NARCIS (Netherlands)

    Udenigwe, Chibuike C.; Fogliano, Vincenzo

    2017-01-01

    Several peptides derived from food protein digestion possess regulatory functions that can lead to health promotion. Such peptides can be used as nutraceuticals and their inclusion as active components of functional food products is increasingly gaining attention. However, physiological evidence to

  11. MALDI-based identification of stable hazelnut protein derived tryptic marker peptides.

    Science.gov (United States)

    Cucu, T; De Meulenaer, B; Devreese, B

    2012-01-01

    Food allergy is an important health problem especially in industrialised countries. Tree nuts, among which are hazelnuts (Corylus avellana), are typically causing serious and life-threatening symptoms in sensitive subjects. Hazelnut is used as a food ingredient in pastry, confectionary products, ice cream and meat products, therefore undeclared hazelnut can be often present as a cross-contaminant representing a threat for allergic consumers. Mass spectrometric techniques are used for the detection of food allergens in processed foods, but limited information regarding stable tryptic peptide markers for hazelnut is available. The aim of this study was to detect stable peptide markers from modified hazelnut protein through the Maillard reaction and oxidation in a buffered solution. Peptides ³⁹⁵Gly-Arg⁴⁰³ from Cor a 11 and ²⁰⁹Gln-Arg²¹⁷, ³⁵¹Ile-Arg³⁶³, ⁴⁶⁴Ala-Arg⁴⁷⁸ and ⁴⁰¹Val-Arg⁴¹⁷ from Cor a 9 hazelnut allergens proved to be the most stable and could be detected and confirmed with high scores in most of the modified samples. The identified peptides can be further used as analytical targets for the development of more robust quantitative methods for hazelnut detection in processed foods.

  12. Comparative syntheses of peptides and peptide thioesters derived from mouse and human prion proteins

    Czech Academy of Sciences Publication Activity Database

    Šebestík, Jaroslav; Zawada, Zbigniew; Šafařík, Martin; Hlaváček, Jan

    2012-01-01

    Roč. 43, č. 3 (2012), s. 1297-1309 ISSN 0939-4451 R&D Projects: GA ČR GA203/07/1517 Institutional research plan: CEZ:AV0Z40550506 Keywords : prion protein segments * classical synthesis * chemical ligation synthesis * peptide thioesters Subject RIV: CC - Organic Chemistry Impact factor: 3.914, year: 2012

  13. 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....

  14. Antioxidant Activity of Purified Active Peptide Derived from Spirulina platensis Enzymatic Hydrolysates

    Directory of Open Access Journals (Sweden)

    Nur Maulida Safitri

    2017-08-01

    Full Text Available The aim of this study is to isolate the antioxidative peptide from Spirulina platensis. Peptide was obtained by proteolytic digestion, ultrafiltration, fractionation by RP-HPLC, identified by LC-MS/MS—MASCOT Distiller and measured its antioxidant activity by DPPH (2.2-Diphenyl-1-picrylhydrazyl assay. Results showed that thermolysin was the most effective enzyme to digest this algae. The active peptide Phe-Ser-Glu-Ser-Ser-Ala-Pro-Glu-Gln-His-Tyr (m/z 1281.51 was identified and synthetized, which exhibited 45.98 ± 1.7% at concentration 128.15 µg/mL. Therefore, S. platensis is indicated as a potential therapeutic source for combating oxidative stress.

  15. High-resolution mapping of linear antibody epitopes using ultrahigh-density peptide microarrays

    DEFF Research Database (Denmark)

    Buus, Søren; Rockberg, Johan; Forsström, Björn

    2012-01-01

    Antibodies empower numerous important scientific, clinical, diagnostic, and industrial applications. Ideally, the epitope(s) targeted by an antibody should be identified and characterized, thereby establishing antibody reactivity, highlighting possible cross-reactivities, and perhaps even warning...... against unwanted (e.g. autoimmune) reactivities. Antibodies target proteins as either conformational or linear epitopes. The latter are typically probed with peptides, but the cost of peptide screening programs tends to prohibit comprehensive specificity analysis. To perform high-throughput, high......-resolution mapping of linear antibody epitopes, we have used ultrahigh-density peptide microarrays generating several hundred thousand different peptides per array. Using exhaustive length and substitution analysis, we have successfully examined the specificity of a panel of polyclonal antibodies raised against...

  16. PEDF-derived peptide promotes skeletal muscle regeneration through its mitogenic effect on muscle progenitor cells.

    Science.gov (United States)

    Ho, Tsung-Chuan; Chiang, Yi-Pin; Chuang, Chih-Kuang; Chen, Show-Li; Hsieh, Jui-Wen; Lan, Yu-Wen; Tsao, Yeou-Ping

    2015-08-01

    In response injury, intrinsic repair mechanisms are activated in skeletal muscle to replace the damaged muscle fibers with new muscle fibers. The regeneration process starts with the proliferation of satellite cells to give rise to myoblasts, which subsequently differentiate terminally into myofibers. Here, we investigated the promotion effect of pigment epithelial-derived factor (PEDF) on muscle regeneration. We report that PEDF and a synthetic PEDF-derived short peptide (PSP; residues Ser(93)-Leu(112)) induce satellite cell proliferation in vitro and promote muscle regeneration in vivo. Extensively, soleus muscle necrosis was induced in rats by bupivacaine, and an injectable alginate gel was used to release the PSP in the injured muscle. PSP delivery was found to stimulate satellite cell proliferation in damaged muscle and enhance the growth of regenerating myofibers, with complete regeneration of normal muscle mass by 2 wk. In cell culture, PEDF/PSP stimulated C2C12 myoblast proliferation, together with a rise in cyclin D1 expression. PEDF induced the phosphorylation of ERK1/2, Akt, and STAT3 in C2C12 myoblasts. Blocking the activity of ERK, Akt, or STAT3 with pharmacological inhibitors attenuated the effects of PEDF/PSP on the induction of C2C12 cell proliferation and cyclin D1 expression. Moreover, 5-bromo-2'-deoxyuridine pulse-labeling demonstrated that PEDF/PSP stimulated primary rat satellite cell proliferation in myofibers in vitro. In summary, we report for the first time that PSP is capable of promoting the regeneration of skeletal muscle. The signaling mechanism involves the ERK, AKT, and STAT3 pathways. These results show the potential utility of this PEDF peptide for muscle regeneration. Copyright © 2015 the American Physiological Society.

  17. A prawn core histone 4: derivation of N- and C-terminal peptides and their antimicrobial properties, molecular characterization and mRNA transcription.

    Science.gov (United States)

    Chaurasia, Mukesh Kumar; Palanisamy, Rajesh; Bhatt, Prasanth; Kumaresan, Venkatesh; Gnanam, Annie J; Pasupuleti, Mukesh; Kasi, Marimuthu; Harikrishnan, Ramaswamy; Arockiaraj, Jesu

    2015-01-01

    This study investigates the complete molecular characterization including bioinformatics characterization, gene expression, synthesis of N and C terminal peptides and their antimicrobial activity of the core histone 4 (H4) from freshwater giant prawn Macrobrachium rosenbergii (Mr). A cDNA encoding MrH4 was identified from the constructed cDNA library of M. rosenbergii during screening and the sequence was obtained using internal sequencing primers. The MrH4 coding region possesses a polypeptide of 103 amino acids with a calculated molecular weight of 11kDa and an isoelectric point of 11.5. The bioinformatics analysis showed that the MrH4 polypeptide contains a H4 signature at (15)GAKRH(19). Multiple sequence alignment of MrH4 showed that the N-terminal (21-42) and C-terminal (87-101) antimicrobial peptide regions and the pentapeptide or H4 signature (15-19) are highly conserved including in humans. The phylogenetic tree formed two separate clades of vertebrate and invertebrate H4, wherein MrH4 was located within the arthropod monophyletic clade of invertebrate H4 groups. Three-dimensional model of MrH4 was established using I-TASSER program and the model was validated using Ramachandran plot analysis. Schiffer-Edmundson helical wheel modeling was used to predict the helix propensity of N (21-42) and C (87-101) terminal derived Mr peptides. The highest gene expression was observed in gills and is induced by viral [white spot syndrome baculovirus (WSBV) and M. rosenbergii nodovirus (MrNV)] and bacterial (Aeromonas hydrophila and Vibrio harveyi) infections. The N and C terminal peptides were synthesized and their antimicrobial and hemolytic properties were examined. Both peptides showed activity against the tested Gram negative and Gram positive bacteria; however, the highest activity was noticed against Gram negative bacteria. Among the two peptides used in this study, C-terminal peptide yielded better results than the N-terminal peptide. Therefore, C terminal

  18. Development of conductivity probe and temperature probe for in-situ measurements in hydrological studies

    International Nuclear Information System (INIS)

    Chandra, U.; Galindo, B.J.; Castagnet, A.C.G.

    1981-05-01

    A conductivity probe and a temperature probe have been developed for in-situ measurements in various hydrological field studies. The conductivity probe has platinum electrodes and is powered with two 12 volt batteries. The sensing element of the temperature probe consists of a resistor of high coefficient of temperature. Response of the conductivity probe is measured in a milliampere mater while the resistance of the thermistor is read by a digital meter. The values of conductivity and temperature are derived from respective calibration. The probes are prototype and their range of measurement can be improved depending upon the requirement of the field problem. (Author) [pt

  19. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

    Rasmussen, Susanne B; Harndahl, Mikkel N; Buus, Anette Stryhn

    2013-01-01

    Mice were immunized twice with a pool of five peptides selected among twenty 8-9-mer peptides for their ability to form stable complexes at 37°C with recombinant H-2K(b) (half-lives 10-15h). Vaccine-induced immunity of splenic CD8(+) T cells was studied in a 24h IFNγ Elispot assay. Surprisingly...... peptides induced normal peptide immunity i.e. the specific T cell reactivity in the Elispot culture was strictly dependent on exposure to the immunizing peptide ex vivo. However, immunization with two of the peptides, a VSV- and a Mycobacterium-derived peptide, resulted in IFNγ spot formation without...... peptide in the Elispot culture. Immunization with a mixture of the VSV-peptide and a "normal" peptide also resulted in IFNγ spot formation without addition of peptide to the assay culture. Peptide-tetramer staining of CD8(+) T cells from mice immunized with a mixture of VSV-peptide and "normal" peptide...

  20. Antimicrobial Peptides of Meat Origin - An In silico and In vitro Analysis.

    Science.gov (United States)

    Keska, Paulina; Stadnik, Joanna

    2017-01-01

    The aim of this study was to evaluate the antimicrobial activity of meat protein-derived peptides against selected Gram-positive and Gram-negative bacteria. The in silico and in vitro approach was combined to determine the potency of antimicrobial peptides derived from pig (Sus scrofa) and cow (Bos taurus) proteins. The in silico studies consisted of an analysis of the amino acid composition of peptides obtained from the CAMPR database, their molecular weight and other physicochemical properties (isoelectric point, molar extinction coefficient, instability index, aliphatic index, hydropathy index and net charge). The degree of similarity was estimated between the antimicrobial peptide sequences derived from the slaughtered animals and the main meat proteins. Antimicrobial activity of peptides isolated from dry-cured meat products was analysed (in vitro) against two strains of pathogenic bacteria using the disc diffusion method. There was no evidence of growthinhibitory properties of peptides isolated from dry-cured meat products against Escherichia coli K12 ATCC 10798 and Staphylococcus aureus ATCC 25923. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. The human VGF-derived bioactive peptide TLQP-21 binds heat shock 71 kDa protein 8 (HSPA8on the surface of SH-SY5Y cells.

    Directory of Open Access Journals (Sweden)

    Shamim Akhter

    Full Text Available VGF (non-acronymicis a secreted chromogranin/secretogranin that gives rise to a number of bioactive peptides by a complex proteolysis mechanism. VGF-derived peptides exert an extensive array of biological effects in energy metabolism, mood regulation, pain, gastric secretion function, reproduction and, perhaps, cancer. It is therefore surprising that very little is known about receptors and binding partners of VGF-derived peptides and their downstream molecular mechanisms of action. Here, using affinity chromatography and mass spectrometry-based protein identification, we have identified the heat shock cognate 71 kDa protein A8 (HSPA8as a binding partner of human TLQP-21 on the surface of human neuroblastomaSH-SY5Y cells. Binding of TLQP-21 to membrane associated HSPA8 in live SH-SY5Y cells was further supported by cross-linking to live cells. Interaction between HSPA8 and TLQP-21 was confirmed in vitro by label-free Dynamic Mass Redistribution (DMR studies. Furthermore, molecular modeling studies show that TLQP-21 can be docked into the HSPA8 peptide binding pocket. Identification of HSPA8 as a cell surface binding partner of TLQP-21 opens new avenues to explore the molecular mechanisms of its physiological actions, and of pharmacological modulation thereof.

  2. The homeodomain derived peptide Penetratin induces curvature of fluid membrane domains.

    Directory of Open Access Journals (Sweden)

    Antonin Lamazière

    Full Text Available BACKGROUND: Protein membrane transduction domains that are able to cross the plasma membrane are present in several transcription factors, such as the homeodomain proteins and the viral proteins such as Tat of HIV-1. Their discovery resulted in both new concepts on the cell communication during development, and the conception of cell penetrating peptide vectors for internalisation of active molecules into cells. A promising cell penetrating peptide is Penetratin, which crosses the cell membranes by a receptor and metabolic energy-independent mechanism. Recent works have claimed that Penetratin and similar peptides are internalized by endocytosis, but other endocytosis-independent mechanisms have been proposed. Endosomes or plasma membranes crossing mechanisms are not well understood. Previously, we have shown that basic peptides induce membrane invaginations suggesting a new mechanism for uptake, "physical endocytosis". METHODOLOGY/PRINCIPAL FINDINGS: Herein, we investigate the role of membrane lipid phases on Penetratin induced membrane deformations (liquid ordered such as in "raft" microdomains versus disordered fluid "non-raft" domains in membrane models. Experimental data show that zwitterionic lipid headgroups take part in the interaction with Penetratin suggesting that the external leaflet lipids of cells plasma membrane are competent for peptide interaction in the absence of net negative charges. NMR and X-ray diffraction data show that the membrane perturbations (tubulation and vesiculation are associated with an increase in membrane negative curvature. These effects on curvature were observed in the liquid disordered but not in the liquid ordered (raft-like membrane domains. CONCLUSIONS/SIGNIFICANCE: The better understanding of the internalisation mechanisms of protein transduction domains will help both the understanding of the mechanisms of cell communication and the development of potential therapeutic molecular vectors. Here we

  3. New Milk Protein-Derived Peptides with Potential Antimicrobial Activity: An Approach Based on Bioinformatic Studies

    Directory of Open Access Journals (Sweden)

    Bartłomiej Dziuba

    2014-08-01

    Full Text Available New peptides with potential antimicrobial activity, encrypted in milk protein sequences, were searched for with the use of bioinformatic tools. The major milk proteins were hydrolyzed in silico by 28 enzymes. The obtained peptides were characterized by the following parameters: molecular weight, isoelectric point, composition and number of amino acid residues, net charge at pH 7.0, aliphatic index, instability index, Boman index, and GRAVY index, and compared with those calculated for known 416 antimicrobial peptides including 59 antimicrobial peptides (AMPs from milk proteins listed in the BIOPEP database. A simple analysis of physico-chemical properties and the values of biological activity indicators were insufficient to select potentially antimicrobial peptides released in silico from milk proteins by proteolytic enzymes. The final selection was made based on the results of multidimensional statistical analysis such as support vector machines (SVM, random forest (RF, artificial neural networks (ANN and discriminant analysis (DA available in the Collection of Anti-Microbial Peptides (CAMP database. Eleven new peptides with potential antimicrobial activity were selected from all peptides released during in silico proteolysis of milk proteins.

  4. High-capacitance supercapacitors using nitrogen-decorated porous carbon derived from novolac resin containing peptide linkage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Jung [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Jang, In Young; Park, Ki Chul; Jung, Yong Chae; Oka, Takuyuki [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Iinou, Satoshi [MEFS, Co. Ltd. Choei Nagano, Higasiguchi Bldg, 2F, 1000-1 Gentakubo, Kurita, Nagano 380-0921 (Japan); Komori, Yasuhiro; Kozutsumi, Toshihiko; Hashiba, Takashi [SHOWA HIGHPOLYMER, Co., Ltd. 1021 Tomizuka-cho, Isesaki-City, Gunma 372-0833 (Japan); Kim, Yoong Ahm, E-mail: yak@endomoribu.shinshu-u.ac.j [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Endo, Morinobu [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)] [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)

    2010-08-01

    We fabricated nitrogen-decorated porous carbon exhibiting high capacitance per unit volume and unit weight via chemical activation of novolac resin containing peptide linkage. The porosity and the amount of nitrogen atoms were controlled by changing the molecular weight of novolac resin, the added amount of potassium hydroxide, or both. After chemical activation, positively charged nitrogen atoms (i.e., pyridine/pyrrole) at 400.3 eV in photoemission spectra contributed to both a shift in the point of zero charge toward negative potential and the generation of pseudocapacitance. Suitably developed pores and the positively charged nitrogen atoms make nitrogen-decorated novolac resin-derived porous carbon a promising material for electrodes in high-performance supercapacitors.

  5. A novel peptide derived from human apolipoprotein E is an inhibitor of tumor growth and ocular angiogenesis.

    Directory of Open Access Journals (Sweden)

    Partha S Bhattacharjee

    2011-01-01

    Full Text Available Angiogenesis is a hallmark of tumor development and metastasis and now a validated target for cancer treatment. We previously reported that a novel dimer peptide (apoEdp derived from the receptor binding region of human apolipoprotein E (apoE inhibits virus-induced angiogenesis. However, its role in tumor anti-angiogenesis is unknown. This study demonstrates that apoEdp has anti-angiogenic property in vivo through reduction of tumor growth in a mouse model and ocular angiogenesis in a rabbit eye model. Our in vitro studies show that apoEdp inhibits human umbilical vein endothelial cell proliferation, migration, invasion and capillary tube formation. We document that apoEdp inhibits vascular endothelial growth factor-induced Flk-1 activation as well as downstream signaling pathways that involve c-Src, Akt, eNOS, FAK, and ERK1/2. These in vitro data suggest potential sites of the apoE dipeptide inhibition that could occur in vivo.This is the first evidence that a synthetic dimer peptide mimicking human apoE has anti-angiogenesis functions and could be an anti-tumor drug candidate.

  6. Tandem MS Analysis of Selenamide-Derivatized Peptide Ions

    Science.gov (United States)

    Zhang, Yun; Zhang, Hao; Cui, Weidong; Chen, Hao

    2011-09-01

    Our previous study showed that selenamide reagents such as ebselen and N-(phenylseleno)phthalimide (NPSP) can be used for selective and rapid derivatization of protein/peptide thiols in high conversion yield. This paper reports the systematic investigation of MS/MS dissociation behaviors of selenamide-derivatized peptide ions upon collision induced dissociation (CID) and electron transfer dissociation (ETD). In the positive ion mode, derivatized peptide ions exhibit tag-dependent CID dissociation pathways. For instance, ebselen-derivatized peptide ions preferentially undergo Se-S bond cleavage upon CID to produce a characteristic fragment ion, the protonated ebselen ( m/z 276), which allows selective identification of thiol peptides from protein digest as well as selective detection of thiol proteins from protein mixture using precursor ion scan (PIS). In contrast, NPSP-derivatized peptide ions retain their phenylselenenyl tags during CID, which is useful in sequencing peptides and locating cysteine residues. In the negative ion CID mode, both types of tags are preferentially lost via the Se-S cleavage, analogous to the S-S bond cleavage during CID of disulfide-containing peptide anions. In consideration of the convenience in preparing selenamide-derivatized peptides and the similarity of Se-S of the tag to the S-S bond, we also examined ETD of the derivatized peptide ions to probe the mechanism for electron-based ion dissociation. Interestingly, facile cleavage of Se-S bond occurs to the peptide ions carrying either protons or alkali metal ions, while backbone cleavage to form c/z ions is severely inhibited. These results are in agreement with the Utah-Washington mechanism proposed for depicting electron-based ion dissociation processes.

  7. Brucella-Salmonella lipopolysaccharide chimeras are less permeable to hydrophobic probes and more sensitive to cationic peptides and EDTA than are their native Brucella sp. counterparts.

    Science.gov (United States)

    Freer, E; Moreno, E; Moriyón, I; Pizarro-Cerdá, J; Weintraub, A; Gorvel, J P

    1996-01-01

    A rough (R) Brucella abortus 45/20 mutant was more sensitive to the bactericidal activity of polymyxin B and lactoferricin B than was its smooth (S) counterpart but considerably more resistant than Salmonella montevideo. The outer membrane (OM) and isolated lipopolysaccharide (LPS) of S. montevideo showed a higher affinity for these cationic peptides than did the corresponding B. abortus OM and LPS. We took advantage of the moderate sensitivity of R B. abortus to cationic peptides to construct live R B. abortus-S-LPS chimeras to test the activities of polymyxin B, lactoferricin B, and EDTA. Homogeneous and abundant peripheral distribution of the heterologous S-LPS was observed on the surface of the chimeras, and this coating had no effect on the viability or morphology of the cells. When the heterologous LPS corresponded to the less sensitive bacterium S B. abortus S19, the chimeras were more resistant to cationic peptides; in contrast, when the S-LPS was from the more sensitive bacterium S. montevideo, the chimeras were more susceptible to the action of peptides and EDTA. A direct correlation between the amount of heterologous S-LPS on the surface of chimeric Brucella cells and peptide sensitivity was observed. Whereas the damage produced by polymyxin B in S. montevideo and B. abortus-S. montevideo S-LPS chimeras was manifested mainly as OM blebbing and inner membrane rolling, lactoferricin B caused inner membrane detachment, vacuolization, and the formation of internal electron-dense granules in these cells. Native S and R B. abortus strains were permeable to the hydrophobic probe N-phenyl-1-naphthylamine (NPN). In contrast, only reduced amounts of NPN partitioned into the OMs of the S. montevideo and B. abortus-S. montevideo S-LPS chimeras. Following peptide exposure, accelerated NPN uptake similar to that observed for S. montevideo was detected for the B. abortus-S. montevideo LPS chimeras. The partition of NPN into native or EDTA-, polymyxin B-, or

  8. Brucella-Salmonella lipopolysaccharide chimeras are less permeable to hydrophobic probes and more sensitive to cationic peptides and EDTA than are their native Brucella sp. counterparts.

    Science.gov (United States)

    Freer, E; Moreno, E; Moriyón, I; Pizarro-Cerdá, J; Weintraub, A; Gorvel, J P

    1996-10-01

    A rough (R) Brucella abortus 45/20 mutant was more sensitive to the bactericidal activity of polymyxin B and lactoferricin B than was its smooth (S) counterpart but considerably more resistant than Salmonella montevideo. The outer membrane (OM) and isolated lipopolysaccharide (LPS) of S. montevideo showed a higher affinity for these cationic peptides than did the corresponding B. abortus OM and LPS. We took advantage of the moderate sensitivity of R B. abortus to cationic peptides to construct live R B. abortus-S-LPS chimeras to test the activities of polymyxin B, lactoferricin B, and EDTA. Homogeneous and abundant peripheral distribution of the heterologous S-LPS was observed on the surface of the chimeras, and this coating had no effect on the viability or morphology of the cells. When the heterologous LPS corresponded to the less sensitive bacterium S B. abortus S19, the chimeras were more resistant to cationic peptides; in contrast, when the S-LPS was from the more sensitive bacterium S. montevideo, the chimeras were more susceptible to the action of peptides and EDTA. A direct correlation between the amount of heterologous S-LPS on the surface of chimeric Brucella cells and peptide sensitivity was observed. Whereas the damage produced by polymyxin B in S. montevideo and B. abortus-S. montevideo S-LPS chimeras was manifested mainly as OM blebbing and inner membrane rolling, lactoferricin B caused inner membrane detachment, vacuolization, and the formation of internal electron-dense granules in these cells. Native S and R B. abortus strains were permeable to the hydrophobic probe N-phenyl-1-naphthylamine (NPN). In contrast, only reduced amounts of NPN partitioned into the OMs of the S. montevideo and B. abortus-S. montevideo S-LPS chimeras. Following peptide exposure, accelerated NPN uptake similar to that observed for S. montevideo was detected for the B. abortus-S. montevideo LPS chimeras. The partition of NPN into native or EDTA-, polymyxin B-, or

  9. Structure-activity relationships of an antimicrobial peptide plantaricin s from two-peptide class IIb bacteriocins.

    Science.gov (United States)

    Soliman, Wael; Wang, Liru; Bhattacharjee, Subir; Kaur, Kamaljit

    2011-04-14

    Class IIb bacteriocins are ribosomally synthesized antimicrobial peptides comprising two different peptides synergistically acting in equal amounts for optimal potency. In this study, we demonstrate for the first time potent (nanomolar) antimicrobial activity of a representative class IIb bacteriocin, plantaricin S (Pls), against four pathogenic gram-positive bacteria, including Listeria monocytogenes. The structure-activity relationships for Pls were studied using activity assays, circular dichroism (CD), and molecular dynamics (MD) simulations. The two Pls peptides and five Pls derived fragments were synthesized. The CD spectra of the Pls and selected fragments revealed helical conformations in aqueous 2,2,2-trifluoroethanol. The MD simulations showed that when the two Pls peptides are in antiparallel orientation, the helical regions interact and align, mediated by strong attraction between conserved GxxxG/AxxxA motifs. The results strongly correlate with the antimicrobial activity suggesting that helix-helix alignment of the two Pls peptides and interaction between the conserved motifs are crucial for interaction with the target cell membrane.

  10. Delayed Treatment with a Small Pigment Epithelium Derived Factor (PEDF Peptide Prevents the Progression of Diabetic Renal Injury.

    Directory of Open Access Journals (Sweden)

    Alaa S Awad

    Full Text Available Our recent publication showed that a small bioactive pigment epithelium derived factor (PEDF peptide (P78-PEDF prevents the development of diabetic nephropathy (DN. However, its effects on the progression of established DN were not clear. Therefore, the purpose of this study was to determine the effect of P78-PEDF in the progression of DN and to compare the effects of P78-PEDF and an ACE inhibitor (ACEi, a standard of care in DN. Experiments were conducted in Ins2(Akita mice treated with P78-PEDF or captopril starting at 6 wks of age for 12 wks (early treatment or starting at 12 wks of age for 6 wks (late treatment. We first established the optimal dose of the P78-PEDF peptide to ameliorate DN in Ins2(Akita mouse for a 6 wk study period and found that the peptide was effective at 0.1- 0.5 µg/g/day. We next showed that early or late treatment with P78-PEDF resulted in protection from DN as indicated by reduced albuminuria, kidney macrophage recruitment, histological changes, inflammatory cytokines and fibrotic markers (kidney TNF-α, fibronectin, VEGFA and EGFR, and restored nephrin expression compared with vehicle-treated Ins2(Akita mice. Interestingly, only early but not late treatment with captopril was as effective as P78-PEDF in reducing most DN complications, despite its lack of effect on nephrin, VEGFA and EGFR expression. These findings highlight the importance of P78-PEDF peptide as a potential therapeutic modality in both the development and progression of diabetic renal injury.

  11. Comparative syntheses of peptide thioesters derived from mouse and human prion proteins

    Czech Academy of Sciences Publication Activity Database

    Šebestík, Jaroslav; Zawada, Zbigniew; Šafařík, Martin; Hlaváček, Jan

    2011-01-01

    Roč. 41, Suppl. 1 (2011), S78-S79 ISSN 0939-4451. [International Congress on Amino Acids, Peptides and Proteins /12./. 01.08.2011-05.08.2011, Beijing] R&D Projects: GA ČR GA203/07/1517 Institutional research plan: CEZ:AV0Z40550506 Keywords : peptide thioesters * ligation * prions * C-domain Subject RIV: CC - Organic Chemistry

  12. Tumor imaging and targeting potential of an Hsp70-derived 14-mer peptide.

    Directory of Open Access Journals (Sweden)

    Mathias Gehrmann

    Full Text Available We have previously used a unique mouse monoclonal antibody cmHsp70.1 to demonstrate the selective presence of a membrane-bound form of Hsp70 (memHsp70 on a variety of leukemia cells and on single cell suspensions derived from solid tumors of different entities, but not on non-transformed cells or cells from corresponding 'healthy' tissue. This antibody can be used to image tumors in vivo and target them for antibody-dependent cellular cytotoxicity. Tumor-specific expression of memHsp70 therefore has the potential to be exploited for theranostic purposes. Given the advantages of peptides as imaging and targeting agents, this study assessed whether a 14-mer tumor penetrating peptide (TPP; TKDNNLLGRFELSG, the sequence of which is derived from the oligomerization domain of Hsp70 which is expressed on the cell surface of tumor cells, can also be used for targeting membrane Hsp70 positive (memHsp70+ tumor cells, in vitro.The specificity of carboxy-fluorescein (CF- labeled TPP (TPP to Hsp70 was proven in an Hsp70 knockout mammary tumor cell system. TPP specifically binds to different memHsp70+ mouse and human tumor cell lines and is rapidly taken up via endosomes. Two to four-fold higher levels of CF-labeled TPP were detected in MCF7 (82% memHsp70+ and MDA-MB-231 (75% memHsp70+ cells compared to T47D cells (29% memHsp70+ that exhibit a lower Hsp70 membrane positivity. After 90 min incubation, TPP co-localized with mitochondrial membranes in memHsp70+ tumors. Although there was no evidence that any given vesicle population was specifically localized, fluorophore-labeled cmHsp70.1 antibody and TPP preferentially accumulated in the proximity of the adherent surface of cultured cells. These findings suggest a potential association between membrane Hsp70 expression and cytoskeletal elements that are involved in adherence, the establishment of intercellular synapses and/or membrane reorganization.This study demonstrates the specific binding and rapid

  13. Chiral thiazoline and thiazole building blocks for the synthesis of peptide-derived natural products.

    Science.gov (United States)

    Just-Baringo, Xavier; Albericio, Fernando; Alvarez, Mercedes

    2014-01-01

    Thiazoline and thiazole heterocycles are privileged motifs found in numerous peptide-derived natural products of biological interest. During the last decades, the synthesis of optically pure building blocks has been addressed by numerous groups, which have developed a plethora of strategies to that end. Efficient and reliable methodologies that are compatible with the intricate and capricious architectures of natural products are a must to further develop their science. Structure confirmation, structure-activity relationship studies and industrial production are fields of paramount importance that require these robust methodologies in order to successfully bring natural products into the clinic. Today's chemist toolbox is assorted with many powerful methods for chiral thiazoline and thiazole synthesis. Ranging from biomimetic approaches to stereoselective alkylations, one is likely to find a suitable method for their needs.

  14. Antibacterial activity of novel peptide derived from Cry1Ab16 toxin and development of LbL films for foodborne pathogens control

    International Nuclear Information System (INIS)

    Plácido, Alexandra; Bragança, Idalina; Marani, Mariela; Rodrigues de Araujo, Alyne; Vasconcelos, Andreanne Gomes; Batziou, Krystallenia; Domingues, Valentina F.

    2017-01-01

    Escherichia coli is one of the most common etiological agents of diarrhea in developing countries. The appearance of resistant E. coli prevents treatment of these infections. Biotechnological products incorporating antimicrobial peptides are currently being considered in applications to prevent intestinal infections by these bacteria. The aim of this study was to evaluate the antibacterial activity of the peptide PcL342-354C, which is derived from the toxin Cry1Ab16 from Bacillus thuringiensis, against E. coli strains. We also report the preparation, characterization and evaluation of the antibacterial activity of LbL films containing PcL342-354C. The results showed that the PcL342-354C peptide inhibited the growth of different strains of E. coli with minimal inhibitory concentration ranging from 15.62–31.25 μg/mL and minimal bactericidal concentration was 250 μg/mL, indicating a potential antibacterial activity. The morphology of an ITO/Cashew gum/PcL342-354C film was analysed using atomic force microscopy which showed an increase of roughness due to the increase in the number of layers. The LbL films showed significant antibacterial activity against E. coli NCTC 9001 in both conditions tested (10 and 20 bilayers). Our results indicate that the peptide exhibits an antibacterial potential that can be tapped to develop biomaterials with antibacterial activity for use against foodborne pathogens. - Highlights: • The PcL342–354C peptide inhibited the growth of E. coli. • The peptide can be simply incorporated into edible films combined with cashew gum. • LbL films incorporating the peptide have antibacterial activity against E. coli. • The PcL342–354C exhibits an antibacterial potential that can be tapped to develop biomaterials.

  15. Antibacterial activity of novel peptide derived from Cry1Ab16 toxin and development of LbL films for foodborne pathogens control

    Energy Technology Data Exchange (ETDEWEB)

    Plácido, Alexandra, E-mail: alexandra.placido@gmail.com [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); Bragança, Idalina, E-mail: linab_20@hotmail.com [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); Marani, Mariela, E-mail: mmarani@cenpat-conicet.gob.ar [IPEEC-CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Puerto Madryn, Chubut (Argentina); Rodrigues de Araujo, Alyne, E-mail: alyne_biomed@hotmail.com [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Ministro Reis Velloso, CMRV, Universidade Federal do Piauí, UFPI, Parnaíba, PI (Brazil); Vasconcelos, Andreanne Gomes, E-mail: andreannegv@gmail.com [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Ministro Reis Velloso, CMRV, Universidade Federal do Piauí, UFPI, Parnaíba, PI (Brazil); Batziou, Krystallenia, E-mail: batkrysta@gmail.com [REQUIMTE/UCIBIO, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto (Portugal); Domingues, Valentina F., E-mail: vfd@isep.ipp.pt [REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, ISEP, Instituto Politécnico do Porto, Porto (Portugal); and others

    2017-06-01

    Escherichia coli is one of the most common etiological agents of diarrhea in developing countries. The appearance of resistant E. coli prevents treatment of these infections. Biotechnological products incorporating antimicrobial peptides are currently being considered in applications to prevent intestinal infections by these bacteria. The aim of this study was to evaluate the antibacterial activity of the peptide PcL342-354C, which is derived from the toxin Cry1Ab16 from Bacillus thuringiensis, against E. coli strains. We also report the preparation, characterization and evaluation of the antibacterial activity of LbL films containing PcL342-354C. The results showed that the PcL342-354C peptide inhibited the growth of different strains of E. coli with minimal inhibitory concentration ranging from 15.62–31.25 μg/mL and minimal bactericidal concentration was 250 μg/mL, indicating a potential antibacterial activity. The morphology of an ITO/Cashew gum/PcL342-354C film was analysed using atomic force microscopy which showed an increase of roughness due to the increase in the number of layers. The LbL films showed significant antibacterial activity against E. coli NCTC 9001 in both conditions tested (10 and 20 bilayers). Our results indicate that the peptide exhibits an antibacterial potential that can be tapped to develop biomaterials with antibacterial activity for use against foodborne pathogens. - Highlights: • The PcL342–354C peptide inhibited the growth of E. coli. • The peptide can be simply incorporated into edible films combined with cashew gum. • LbL films incorporating the peptide have antibacterial activity against E. coli. • The PcL342–354C exhibits an antibacterial potential that can be tapped to develop biomaterials.

  16. Towards generation of bioactive peptides from meat industry waste proteins: Generation of peptides using commercial microbial proteases.

    Science.gov (United States)

    Ryder, Kate; Bekhit, Alaa El-Din; McConnell, Michelle; Carne, Alan

    2016-10-01

    Five commercially available food-grade microbial protease preparations were evaluated for their ability to hydrolyse meat myofibrillar and connective tissue protein extracts to produce bioactive peptides. A bacterial-derived protease (HT) extensively hydrolysed both meat protein extracts, producing peptide hydrolysates with significant in vitro antioxidant and ACE inhibitor activities. The hydrolysates retained bioactivity after simulated gastrointestinal hydrolysis challenge. Gel permeation chromatography sub-fractionation of the crude protein hydrolysates showed that the smaller peptide fractions exhibited the highest antioxidant and ACE inhibitor activities. OFFGEL electrophoresis of the small peptides of both hydrolysates showed that low isoelectric point peptides had antioxidant activity; however, no consistent relationship was observed between isoelectric point and ACE inhibition. Cell-based assays indicated that the hydrolysates present no significant cytotoxicity towards Vero cells. The results indicate that HT protease hydrolysis of meat myofibrillar and connective tissue protein extracts produces bioactive peptides that are non-cytotoxic, should be stable in the gastrointestinal tract and may contain novel bioactive peptide sequences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Marine Peptides: Bioactivities and Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-06-01

    Full Text Available Peptides are important bioactive natural products which are present in many marine species. These marine peptides have high potential nutraceutical and medicinal values because of their broad spectra of bioactivities. Their antimicrobial, antiviral, antitumor, antioxidative, cardioprotective (antihypertensive, antiatherosclerotic and anticoagulant, immunomodulatory, analgesic, anxiolytic anti-diabetic, appetite suppressing and neuroprotective activities have attracted the attention of the pharmaceutical industry, which attempts to design them for use in the treatment or prevention of various diseases. Some marine peptides or their derivatives have high commercial values and had reached the pharmaceutical and nutraceutical markets. A large number of them are already in different phases of the clinical and preclinical pipeline. This review highlights the recent research in marine peptides and the trends and prospects for the future, with special emphasis on nutraceutical and pharmaceutical development into marketed products.

  18. Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure.

    Directory of Open Access Journals (Sweden)

    Lijun Chao

    Full Text Available The HIV-1 envelope glycoprotein (Env gp41 plays a crucial role in the viral fusion process. The peptides derived from the C-terminal heptad repeat (CHR of gp41 are potent HIV fusion inhibitors. However, the activity of these anti-HIV-1 peptides in vivo may be attenuated by their induction of anti-gp41 antibodies. Thus, it is essential to identify antiviral peptides or proteins with low, or no, immunogenicity to humans. Here, we found that the C-terminal fragment (aa 462-521 of the human POB1 (the partner of RalBP1, designated C60, is an HIV-1 fusion inhibitor. It bound to N36, the peptide derived from the N-terminal heptad repeat (NHR of gp41, and to the six-helix bundle (6-HB formed by N36 and C34, a CHR-peptide, but it did not bind to C34. Unlike the CHR-peptides, C60 did not block gp41 6-HB formation. Rather, results suggest that C60 inhibits HIV-1 fusion by binding to the 6-HB, in particular, the residues in the gp41 NHR domain that are exposed on the surface of 6-HB. Since 6-HB plays a crucial role in the late stage of fusion between the viral envelope and endosomal membrane during the endocytic process of HIV-1, C60 may serve as a host restriction factor to suppress HIV-1 entry into CD4+ T lymphocytes. Taken together, it can be concluded from these results that C60 can be used as a lead for the development of anti-HIV-1 therapeutics or microbicides for the treatment and prevention of HIV-1 infection, as well as a molecular probe to study the fusogenic mechanism of HIV-1.

  19. Peptides derived from the solvent-exposed loops 3 and 4 of BDNF bind TrkB and p75(NTR) receptors and stimulate neurite outgrowth and survival

    DEFF Research Database (Denmark)

    Fobian, Kristina; Owczarek, Sylwia; Budtz, Christian

    2010-01-01

    Brain-derived neurotrophic factor (BDNF) is critically involved in modeling the developing nervous system and is an important regulator of a variety of crucial functions in the mature CNS. BDNF exerts its action through interactions with two transmembrane receptors, either separately or in concert....... BDNF has been implicated in several neurological disorders, and irregularities in BDNF function may have severe consequences. Administration of BDNF as a drug has thus far yielded few practicable results, and the potential side effects when using a multifunctional protein are substantial. In an effort...... to produce more specific compounds without side effects, small peptides mimicking protein function have been developed. The present study characterized two mimetic peptides, Betrofin 3 and Betrofin 4, derived from the BDNF sequence. Both Betrofins bound the cognate BDNF receptors, TrkB and p75(NTR...

  20. Preliminary study on the inhibition of nuclear internalization of Tat peptides by conjugation with a receptor-specific peptide and fluorescent dyes

    Science.gov (United States)

    Shen, Duanwen; Liang, Kexiang; Ye, Yunpeng; Tetteh, Elizabeth; Achilefu, Samuel

    2006-02-01

    Numerous studies have shown that basic Tat peptide (48-57) internalized non-specifically in cells and localized in the nucleus. However, localization of imaging agents in cellular nucleus is not desirable because of the potential mutagenesis. When conjugated to the peptides that undergo receptor-mediated endocytosis, Tat peptide could target specific cells or pathologic tissue. We tested this hypothesis by incorporating a somatostatin receptor-avid peptide (octreotate, Oct) and two different fluorescent dyes, Cypate 2 (Cy2) and fluorescein 5'-carboxlic acid (5-FAM), into the Tat-peptide sequence. In addition to the Cy2 or 5-FAM-labeled Oct conjugated to Tat peptide (Tat) to produce Tat-Oct-Cypate2 or Tat-Oct-5-FAM, we also labeled the Tat the Tat peptide with these dyes (Tat-Cy2 and Tat-5-FAM) to serve as positive control. A somatostatin receptor-positive pancreatic tumor cell line, AR42J, was used to assess cell internalization. The results show that Tat-5-FAM and Tat-Cypate2 localized in both nucleus and cytoplasm of the cells. In contrast to Tat-Oct-Cypate2, which localized in both the cytoplasm and nucleus, Tat-Oct-5-FAM internalized in the cytoplasm but not in the nucleus of AR42J cells. The internalizations were inhibited by adding non-labeled corresponding peptides, suggesting that the endocytoses of each group of labeled and the corresponding unlabeled compounds occurred through a common pathway. Thus, fluorescent probes and endocytosis complex between octreotate and somatostatin receptors in cytoplasm could control nuclear internalization of Tat peptides.

  1. Development of protective autoimmunity by immunization with a neural-derived peptide is ineffective in severe spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Susana Martiñón

    Full Text Available Protective autoimmunity (PA is a physiological response to central nervous system trauma that has demonstrated to promote neuroprotection after spinal cord injury (SCI. To reach its beneficial effect, PA should be boosted by immunizing with neural constituents or neural-derived peptides such as A91. Immunizing with A91 has shown to promote neuroprotection after SCI and its use has proven to be feasible in a clinical setting. The broad applications of neural-derived peptides make it important to determine the main features of this anti-A91 response. For this purpose, adult Sprague-Dawley rats were subjected to a spinal cord contusion (SCC; moderate or severe or a spinal cord transection (SCT; complete or incomplete. Immediately after injury, animals were immunized with PBS or A91. Motor recovery, T cell-specific response against A91 and the levels of IL-4, IFN-γ and brain-derived neurotrophic factor (BDNF released by A91-specific T (T(A91 cells were evaluated. Rats with moderate SCC, presented a better motor recovery after A91 immunization. Animals with moderate SCC or incomplete SCT showed significant T cell proliferation against A91 that was characterized chiefly by the predominant production of IL-4 and the release of BDNF. In contrast, immunization with A91 did not promote a better motor recovery in animals with severe SCC or complete SCT. In fact, T cell proliferation against A91 was diminished in these animals. The present results suggest that the effective development of PA and, consequently, the beneficial effects of immunizing with A91 significantly depend on the severity of SCI. This could mainly be attributed to the lack of T(A91 cells which predominantly showed to have a Th2 phenotype capable of producing BDNF, further promoting neuroprotection.

  2. Lactoferricin-related peptides with inhibitory effects on ACE-dependent vasoconstriction.

    Science.gov (United States)

    Centeno, José M; Burguete, María C; Castelló-Ruiz, María; Enrique, María; Vallés, Salvador; Salom, Juan B; Torregrosa, Germán; Marcos, José F; Alborch, Enrique; Manzanares, Paloma

    2006-07-26

    A selection of lactoferricin B (LfcinB)-related peptides with an angiotensin I-converting enzyme (ACE) inhibitory effect have been examined using in vitro and ex vivo functional assays. Peptides that were analyzed included a set of sequence-related antimicrobial hexapeptides previously reported and two representative LfcinB-derived peptides. In vitro assays using hippuryl-L-histidyl-L-leucine (HHL) and angiotensin I as substrates allowed us to select two hexapeptides, PACEI32 (Ac-RKWHFW-NH2) and PACEI34 (Ac-RKWLFW-NH2), and also a LfcinB-derived peptide, LfcinB17-31 (Ac-FKCRRWQWRMKKLGA-NH2). Ex vivo functional assays using rabbit carotid arterial segments showed PACEI32 (both D- and L-enantiomers) and LfcinB17-31 have inhibitory effects on ACE-dependent angiotensin I-induced contraction. None of the peptides exhibited in vitro ACE inhibitory activity using bradykinin as the substrate. In conclusion, three bioactive lactoferricin-related peptides exhibit inhibitory effects on both ACE activity and ACE-dependent vasoconstriction with potential to modulate hypertension that deserves further investigation.

  3. Acyl transfer from membrane lipids to peptides is a generic process.

    Science.gov (United States)

    Dods, Robert H; Bechinger, Burkhard; Mosely, Jackie A; Sanderson, John M

    2013-11-15

    The generality of acyl transfer from phospholipids to membrane-active peptides has been probed using liquid chromatography-mass spectrometry analysis of peptide-lipid mixtures. The peptides examined include melittin, magainin II, PGLa, LAK1, LAK3 and penetratin. Peptides were added to liposomes with membrane lipid compositions ranging from pure phosphatidylcholine (PC) to mixtures of PC with phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol. Experiments were typically conducted at pH7.4 at modest salt concentrations (90 mM NaCl). In favorable cases, lipidated peptides were further characterized by tandem mass spectrometry methods to determine the sites of acylation. Melittin and magainin II were the most reactive peptides, with significant acyl transfer detected under all conditions and membrane compositions. Both peptides were lipidated at the N-terminus by transfer from PC, phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol, as well as at internal sites: lysine for melittin; serine and lysine for magainin II. Acyl transfer could be detected within 3h of melittin addition to negatively charged membranes. The other peptides were less reactive, but for each peptide, acylation was found to occur in at least one of the conditions examined. The data demonstrate that acyl transfer is a generic process for peptides bound to membranes composed of diacylglycerophospholipids. Phospholipid membranes cannot therefore be considered as chemically inert toward peptides and by extension proteins. © 2013. Published by Elsevier Ltd. All rights reserved.

  4. Bioelectronic Nose Using Odorant Binding Protein-Derived Peptide and Carbon Nanotube Field-Effect Transistor for the Assessment of Salmonella Contamination in Food.

    Science.gov (United States)

    Son, Manki; Kim, Daesan; Kang, Jinkyung; Lim, Jong Hyun; Lee, Seung Hwan; Ko, Hwi Jin; Hong, Seunghun; Park, Tai Hyun

    2016-12-06

    Salmonella infection is the one of the major causes of food borne illnesses including fever, abdominal pain, diarrhea, and nausea. Thus, early detection of Salmonella contamination is important for our healthy life. Conventional detection methods for the food contamination have limitations in sensitivity and rapidity; thus, the early detection has been difficult. Herein, we developed a bioelectronic nose using a carbon nanotube (CNT) field-effect transistor (FET) functionalized with Drosophila odorant binding protein (OBP)-derived peptide for easy and rapid detection of Salmonella contamination in ham. 3-Methyl-1-butanol is known as a specific volatile organic compound, generated from the ham contaminated with Salmonella. We designed and synthesized the peptide based on the sequence of the Drosophila OBP, LUSH, which specifically binds to alcohols. The C-terminus of the synthetic peptide was modified with three phenylalanine residues and directly immobilized onto CNT channels using the π-π interaction. The p-type properties of FET were clearly maintained after the functionalization using the peptide. The biosensor detected 1 fM of 3-methyl-1-butanol with high selectivity and successfully assessed Salmonella contamination in ham. These results indicate that the bioelectronic nose can be used for the rapid detection of Salmonella contamination in food.

  5. Quinacrine reactivity with prion proteins and prion-derived peptides

    Czech Academy of Sciences Publication Activity Database

    Zawada, Zbigniew; Šafařík, Martin; Dvořáková, E.; Janoušková, O.; Březinová, Anna; Stibor, Ivan; Holada, K.; Bouř, Petr; Hlaváček, Jan; Šebestík, Jaroslav

    2013-01-01

    Roč. 44, č. 5 (2013), s. 1279-1292 ISSN 0939-4451 R&D Projects: GA ČR GA203/07/1517 Institutional support: RVO:61388963 Keywords : quinacrine * prion protein and peptide model reactions * solid phase and recombinant synthesis Subject RIV: CE - Biochemistry Impact factor: 3.653, year: 2013

  6. 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.

  7. Synthesis of Mikto-Arm Star Peptide Conjugates.

    Science.gov (United States)

    Koo, Jin Mo; Su, Hao; Lin, Yi-An; Cui, Honggang

    2018-01-01

    Mikto-arm star peptide conjugates are an emerging class of self-assembling peptide-based structural units that contain three or more auxiliary segments of different chemical compositions and/or functionalities. This group of molecules exhibit interesting self-assembly behavior in solution due to their chemically asymmetric topology. Here we describe the detailed procedure for synthesis of an ABC Mikto-arm star peptide conjugate in which two immiscible entities (a saturated hydrocarbon and a hydrophobic and lipophobic fluorocarbon) are conjugated onto a short β-sheet forming peptide sequence, GNNQQNY, derived from the Sup35 prion, through a lysine junction. Automated and manual Fmoc-solid phase synthesis techniques are used to synthesize the Mikto-arm star peptide conjugates, followed by HPLC purification. We envision that this set of protocols can afford a versatile platform to synthesize a new class of peptidic building units for diverse applications.

  8. Seahorse-derived peptide suppresses invasive migration of HT1080 fibrosarcoma cells by competing with intracellular α-enolase for plasminogen binding and inhibiting uPA-mediated activation of plasminogen.

    Science.gov (United States)

    Kim, Yong-Tae; Kim, Se-kwon; Jeon, You-Jin; Park, Sun Joo

    2014-12-01

    α-Enolase is a glycolytic enzyme and a surface receptor for plasminogen. α-Enolase-bound plasminogen promotes tumor cell invasion and cancer metastasis by activating plasmin and consequently degrading the extracellular matrix degradation. Therefore, α-enolase and plasminogen are novel targets for cancer therapy. We found that the amino acid sequence of a peptide purified from enzymatic hydrolysates of seahorse has striking similarities to that of α-enolase. In this study, we report that this peptide competes with cellular α-enolase for plasminogen binding and suppresses urokinase plasminogen activator (uPA)-mediated activation of plasminogen, which results in decreased invasive migration of HT1080 fibrosarcoma cells. In addition, the peptide treatment decreased the expression levels of uPA compared to that of untreated controls. These results provide new insight into the mechanism by which the seahorse-derived peptide suppresses invasive properties of human cancer cells. Our findings suggest that this peptide could emerge as a potential therapeutic agent for cancer.

  9. Halogenation dictates the architecture of amyloid peptide nanostructures.

    Science.gov (United States)

    Pizzi, Andrea; Pigliacelli, Claudia; Gori, Alessandro; Nonappa; Ikkala, Olli; Demitri, Nicola; Terraneo, Giancarlo; Castelletto, Valeria; Hamley, Ian W; Baldelli Bombelli, Francesca; Metrangolo, Pierangelo

    2017-07-20

    Amyloid peptides yield a plethora of interesting nanostructures though difficult to control. Here we report that depending on the number, position, and nature of the halogen atoms introduced into either one or both phenylalanine benzene rings of the amyloid β peptide-derived core-sequence KLVFF, four different architectures were obtained in a controlled manner. Our findings demonstrate that halogenation may develop as a general strategy to engineer amyloidal peptide self-assembly and obtain new amyloidal nanostructures.

  10. Why bacteria derived R-M nucleic enzymatic peptides are likely ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... (3) Human genome contains several palindromes recognizable by R-M peptides, making ..... mutation and likely has affected genome evolution. .... Microbicide to prevent sexual transmission of HIV among high risk.

  11. Rapid purification of radioiodinated peptides with Sep-Pak reversed phase cartridges and HPLC

    International Nuclear Information System (INIS)

    Miller, J.J.; Schultz, G.S.; Levy, R.S.

    1984-01-01

    A simple, rapid method is described for the purification of radioiodinated peptides for use in radioimmuno- and in radioreceptor assays. Iodinated reaction mixtures are applied directly onto Sep-Pak disposable, reversed phase cartridges equilibrated with phosphate buffer. Unreacted 125-iodide and other non-peptide reaction components are eluted with buffer. The peptide fraction is then eluted with 70% buffer:30% acetonitrile. The peptide fraction is further purified by reversed phase high pressure liquid chromatography to separate the native peptide and the mono- and diiodo-derivatives. In this study the method is used to prepare 125-iodide-labeled monoiodo-leucine enkephalin and monoiodo-angiotensin II, which are free of the parent peptides and diiodo-derivatives and are of maximum obtainable specific radioactivity. The usefulness of these labeled peptides in radioimmuno- and radioreceptor assays is demonstrated by their binding to specific antibodies and receptors, respectively. (author)

  12. Kinetic analysis of the mechanism and specificity of protein-disulfide isomerase using fluorescence-quenched peptides

    DEFF Research Database (Denmark)

    Westphal, V; Spetzler, J C; Meldal, M

    1998-01-01

    Protein-disulfide isomerase (PDI) is an abundant folding catalyst in the endoplasmic reticulum of eukaryotic cells. PDI introduces disulfide bonds into newly synthesized proteins and catalyzes disulfide bond isomerizations. We have synthesized a library of disulfide-linked fluorescence......-quenched peptides, individually linked to resin beads, for two purposes: 1) to probe PDI specificity, and 2) to identify simple, sensitive peptide substrates of PDI. Using this library, beads that became rapidly fluorescent by reduction by human PDI were selected. Amino acid sequencing of the bead-linked peptides...

  13. 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.

  14. 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.

  15. Experimental Peptide Identification Repository (EPIR): an integrated peptide-centric platform for validation and mining of tandem mass spectrometry data

    DEFF Research Database (Denmark)

    Kristensen, Dan Bach; Brønd, Jan Christian; Nielsen, Peter Aagaard

    2004-01-01

    LC MS/MS has become an established technology in proteomic studies, and with the maturation of the technology the bottleneck has shifted from data generation to data validation and mining. To address this bottleneck we developed Experimental Peptide Identification Repository (EPIR), which...... is an integrated software platform for storage, validation, and mining of LC MS/MS-derived peptide evidence. EPIR is a cumulative data repository where precursor ions are linked to peptide assignments and protein associations returned by a search engine (e.g. Mascot, Sequest, or PepSea). Any number of datasets can...

  16. Neuromedin and FN-38 Peptides for Treating Psychiatric Diseases

    Science.gov (United States)

    Methods and compositions for treating psychiatric diseases and disorders are disclosed. The methods provided generally involve the administration of an NMX peptide, an FNX peptide, or an NMX receptor agonist, or analogs or derivatives thereof, to a subject in order to treat psychiatric diseases and ...

  17. Functional characterization of a synthetic hydrophilic antifungal peptide derived from the marine snail Cenchritis muricatus.

    Science.gov (United States)

    López-Abarrategui, Carlos; Alba, Annia; Silva, Osmar N; Reyes-Acosta, Osvaldo; Vasconcelos, Ilka M; Oliveira, Jose T A; Migliolo, Ludovico; Costa, Maysa P; Costa, Carolina R; Silva, Maria R R; Garay, Hilda E; Dias, Simoni C; Franco, Octávio L; Otero-González, Anselmo J

    2012-04-01

    Antimicrobial peptides have been found in mollusks and other sea animals. In this report, a crude extract of the marine snail Cenchritis muricatus was evaluated against human pathogens responsible for multiple deleterious effects and diseases. A peptide of 1485.26 Da was purified by reversed-phase HPLC and functionally characterized. This trypsinized peptide was sequenced by MS/MS technology, and a sequence (SRSELIVHQR), named Cm-p1 was recovered, chemically synthesized and functionally characterized. This peptide demonstrated the capacity to prevent the development of yeasts and filamentous fungi. Otherwise, Cm-p1 displayed no toxic effects against mammalian cells. Molecular modeling analyses showed that this peptide possible forms a single hydrophilic α-helix and the probable cationic residue involved in antifungal activity action is proposed. The data reported here demonstrate the importance of sea animals peptide discovery for biotechnological tools development that could be useful in solving human health and agribusiness problems. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  18. Peptides derived from tryptic hydrolysate of Bacillus subtilis culture suppress fungal spoilage of table grapes.

    Science.gov (United States)

    Zhang, Bo; Wang, Jingnan; Ning, Shuqing; Yuan, Quan; Chen, Xiangning; Zhang, Yanyan; Fan, Junfeng

    2018-01-15

    This study confirmed the anti-fungal effect of trypsin-treated Bacillus subtilis culture (BC) (tryptic hydrolysate, TH) on mold growth on Kyoho grapes. We examined the anti-fungal activity of TH by identifying TH peptides and performing a computational docking analysis. TH was more potent than untreated BC in suppressing fungal growth on grapes. Specifically, TH maintained grape freshness by inhibiting respiration and rachis browning, maintaining firmness, and preventing weight loss. Thirty-six inhibitory peptides against β-1,3-glucan synthase (GS) were screened from 126 TH peptides identified through proteomic analysis. Among them, 13 peptides bound tightly to GS active pockets with lower binding energies than that of GppNHp. The most potent peptides, LFEIDEELNEK and FATSDLNDLYR, were synthesized, and further experiments showed that these peptides had a highly suppressive effect on GS activity and Aspergillus niger and Penicillium chrysogenum growth. Our results confirm that tryptic treatment is effective for improving the anti-fungal activity of BC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Entry of a Six-Residue Antimicrobial Peptide Derived from Lactoferricin B into Single Vesicles and Escherichia coli Cells without Damaging their Membranes.

    Science.gov (United States)

    Moniruzzaman, Md; Islam, Md Zahidul; Sharmin, Sabrina; Dohra, Hideo; Yamazaki, Masahito

    2017-08-22

    Lactoferricin B (LfcinB) and shorter versions of this peptide have antimicrobial activity. However, the elementary processes of interactions of these peptides with lipid membranes and bacteria are still not well understood. To elucidate the mechanism of their antimicrobial activity, we investigated the interactions of LfcinB (4-9) (its sequence of RRWQWR) with Escherichia coli cells and giant unilamellar vesicles (GUVs). LfcinB (4-9) and lissamine rhodamine B red-labeled LfcinB (4-9) (Rh-LfcinB (4-9)) did not induce an influx of a membrane-impermeant fluorescent probe, SYTOX green, from the outside of E. coli cells into their cytoplasm, indicating that no damage occurred in their plasma membrane. To examine the activity of LfcinB (4-9) to enter E. coli cytoplasm, we investigated the interaction of Rh-LfcinB (4-9) with single cells of E. coli containing calcein using confocal microscopy. We found that Rh-LfcinB (4-9) entered the cytoplasm without leakage of calcein. Next, we investigated the interactions of Rh-LfcinB (4-9) with single GUVs of dioleoylphosphatidylglycerol (DOPG) and dioleoylphosphatidylcholine (DOPC) mixtures containing a fluorescent probe, Alexa Fluor 647 hydrazide (AF647), using the single GUV method. The results indicate that Rh-LfcinB (4-9) outside the GUV translocated through the GUV membrane and entered its lumen without leakage of AF647. Interaction of Rh-LfcinB (4-9) with DNA increased its fluorescence intensity greatly. Therefore, we can conclude that Rh-LfcinB (4-9) can translocate across lipid membrane regions of the plasma membrane of E. coli cells to enter their cytoplasm without leakage of calcein and its antimicrobial activity is not due to damage of their plasma membranes.

  20. Linear and nonlinear photophysics and bioimaging of an integrin-targeting water-soluble fluorenyl probe.

    Science.gov (United States)

    Morales, Alma R; Luchita, Gheorghe; Yanez, Ciceron O; Bondar, Mykhailo V; Przhonska, Olga V; Belfield, Kevin D

    2010-06-07

    Linear photophysical characterization and two-photon absorption (2PA) properties of a new water-soluble fluorene derivative, 3-(9-(2-(2-methoxyethoxy)ethyl)-2,7-bis{3-[2-(polyethyleneglycol-550-monomethylether-1-yl)]-4-(benzo[d]thiazol-2-yl)styryl}-9H-fluoren-9-yl)propanoic acid (1), were investigated in several organic solvents and water at room temperature. A comprehensive analysis of the steady-state absorption, emission and excitation anisotropy spectra revealed electronic structures of 1, including mutual orientation of the transition dipoles, relatively weak solvatochromic effects, high fluorescence quantum yield (approximately 0.5-1.0), and strong aggregation in water. The 2PA spectra of 1 were obtained in the 600-900 nm spectral range by two-photon induced fluorescence (2PF) and open aperture Z-scan methods using femtosecond laser sources. No discrete 2PA bands were apparent and values of the corresponding 2PA cross sections monotonically increased in the short wavelength range up to 3000 GM in organic solvents and approximately 6000 GM in aqueous solution, reflecting relatively high two-photon absorptivity. The 2PA efficiency of in water increased 2-3 times relative to aprotic solvents and can be explained by cooperative electronic effects of molecular aggregates of 1 produced in aqueous media. The carboxylic acid fluorenyl probe 1 was conjugated with the cyclic peptide RGDfK. Two-photon fluorescence microscopy (2PFM) imaging of U87MG cells (and MCF-7 as control), incubated with fluorene-RGD peptide conjugate 2, demonstrated high alpha(v)beta(3) integrin selectivity, making this probe particularly attractive for integrin imaging.

  1. Antimicrobial properties of analgesic kyotorphin peptides unraveled through atomic force microscopy

    International Nuclear Information System (INIS)

    Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Inês M.; Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R.; Castanho, Miguel A.R.B.

    2012-01-01

    Highlights: ► New kyotorphin derivatives have antimicrobial properties against S. aureus. ► Atomic force microscopy show membrane disturbing effects of KTP–NH 2 and IbKTP–NH 2 . ► None of the KTP derivatives are hemolytic. ► The minimal peptidic sequence with antimicrobial activity is Tyr-Arg, if amidated. -- Abstract: Antimicrobial peptides (AMPs) are promising candidates as alternatives to conventional antibiotics for the treatment of resistant pathogens. In the last decades, new AMPs have been found from the cleavage of intact proteins with no antibacterial activity themselves. Bovine hemoglobin hydrolysis, for instance, results in AMPs and the minimal antimicrobial peptide sequence was defined as Tyr-Arg plus a positively charged amino acid residue. The Tyr-Arg dipeptide alone, known as kyotorphin (KTP), is an endogenous analgesic neuropeptide but has no antimicrobial activity itself. In previous studies new KTP derivatives combining C-terminal amidation and Ibuprofen (Ib) – KTP–NH 2 , IbKTP, IbKTP–NH 2 – were designed in order to improve KTP brain targeting. Those modifications succeeded in enhancing peptide-cell membrane affinity towards fluid anionic lipids and higher analgesic activity after systemic injection resulted therefrom. Here, we investigated if this affinity for anionic lipid membranes also translates into antimicrobial activity because bacteria have anionic membranes. Atomic force microscopy revealed that KTP derivatives perturbed Staphylococcus aureus membrane structure by inducing membrane blebbing, disruption and lysis. In addition, these peptides bind to red blood cells but are non-hemolytic. From the KTP derivatives tested, amidated KTP proves to be the most active antibacterial agent. The combination of analgesia and antibacterial activities with absence of toxicity is highly appealing from the clinical point of view and broadens the therapeutic potential and application of kyotorphin peptides.

  2. Antimicrobial properties of analgesic kyotorphin peptides unraveled through atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Ines M. [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal); Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R. [Laboratori d' Innovacio en Processos i Productes de Sintesi Organica (LIPPSO), Departament de Quimica, Universitat de Girona, Campus Montilivi, 17071 Girona (Spain); Castanho, Miguel A.R.B., E-mail: macastanho@fm.ul.pt [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer New kyotorphin derivatives have antimicrobial properties against S. aureus. Black-Right-Pointing-Pointer Atomic force microscopy show membrane disturbing effects of KTP-NH{sub 2} and IbKTP-NH{sub 2}. Black-Right-Pointing-Pointer None of the KTP derivatives are hemolytic. Black-Right-Pointing-Pointer The minimal peptidic sequence with antimicrobial activity is Tyr-Arg, if amidated. -- Abstract: Antimicrobial peptides (AMPs) are promising candidates as alternatives to conventional antibiotics for the treatment of resistant pathogens. In the last decades, new AMPs have been found from the cleavage of intact proteins with no antibacterial activity themselves. Bovine hemoglobin hydrolysis, for instance, results in AMPs and the minimal antimicrobial peptide sequence was defined as Tyr-Arg plus a positively charged amino acid residue. The Tyr-Arg dipeptide alone, known as kyotorphin (KTP), is an endogenous analgesic neuropeptide but has no antimicrobial activity itself. In previous studies new KTP derivatives combining C-terminal amidation and Ibuprofen (Ib) - KTP-NH{sub 2}, IbKTP, IbKTP-NH{sub 2} - were designed in order to improve KTP brain targeting. Those modifications succeeded in enhancing peptide-cell membrane affinity towards fluid anionic lipids and higher analgesic activity after systemic injection resulted therefrom. Here, we investigated if this affinity for anionic lipid membranes also translates into antimicrobial activity because bacteria have anionic membranes. Atomic force microscopy revealed that KTP derivatives perturbed Staphylococcus aureus membrane structure by inducing membrane blebbing, disruption and lysis. In addition, these peptides bind to red blood cells but are non-hemolytic. From the KTP derivatives tested, amidated KTP proves to be the most active antibacterial agent. The combination of analgesia and antibacterial activities with absence of toxicity is highly appealing from the clinical point of view

  3. An approach to the construction of tailor-made amphiphilic peptides that strongly and selectively bind to hairpin RNA targets.

    Science.gov (United States)

    Lee, Su Jin; Hyun, Soonsil; Kieft, Jeffrey S; Yu, Jaehoon

    2009-02-18

    The hairpin RNA motif is one of the most frequently observed secondary structures and is often targeted by therapeutic agents. An amphiphilic peptide with seven lysine and eight leucine residues and its derivatives were designed for use as ligands against RNA hairpin motifs. We hypothesized that variations in both the hydrophobic leucine-rich and hydrophilic lysine-rich spheres of these amphiphilic peptides would create extra attractive interactions with hairpin RNA targets. A series of alanine-scanned peptides were probed to identify the most influential lysine residues in the hydrophilic sphere. The binding affinities of these modified peptides with several hairpins, such as RRE, TAR from HIV, a short hairpin from IRES of HCV, and a hairpin from the 16S A-site stem from rRNA, were determined. Since the hairpin from IRES of HCV was the most susceptible to the initial series of alanine-scanned peptides, studies investigating how further variations in the peptides effect binding employed the IRES hairpin. Next, the important Lys residues were substituted by shorter chain amines, such as ornithine, to place the peptide deeper into the hairpin groove. In a few cases, a 70-fold improved binding was observed for peptides that contained the specifically located shorter amine side chains. To further explore changes in binding affinities brought about by alterations in the hydrophobic sphere, tryptophan residues were introduced in place of leucine. A few peptides with tryptophan in specific positions also displayed 70-fold improved binding affinities. Finally, double mutant peptides incorporating both specifically located shorter amine side chains in the hydrophilic region and tryptophan residues in the hydrophobic region were synthesized. The binding affinities of peptides containing the simple double modification were observed to be 80 times lower, and their binding specificities were increased 40-fold. The results of this effort provide important information about

  4. 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.

  5. Identification and screening of potent antimicrobial peptides in arthropod genomes.

    Science.gov (United States)

    Duwadi, Deepesh; Shrestha, Anishma; Yilma, Binyam; Kozlovski, Itamar; Sa-Eed, Munaya; Dahal, Nikesh; Jukosky, James

    2018-05-01

    Using tBLASTn and BLASTp searches, we queried recently sequenced arthropod genomes and expressed sequence tags (ESTs) using a database of known arthropod cecropins, defensins, and attacins. We identified and synthesized 6 potential AMPs and screened them for antimicrobial activity. Using radial diffusion assays and microtiter antimicrobial assays, we assessed the in vitro antimicrobial effects of these peptides against several human pathogens including Gram-positive and Gram-negative bacteria and fungi. We also conducted hemolysis assays to examine the cytotoxicity of these peptides to mammalian cells. Four of the six peptides identified showed antimicrobial effects in these assays. We also created truncated versions of these four peptides to assay their antimicrobial activity. Two cecropins derived from the monarch butterfly genome (Danaus plexippus), DAN1 and DAN2, showed minimum inhibitory concentrations (MICs) in the range of 2-16 μg/ml when screened against Gram-negative bacteria. HOLO1 and LOUDEF1, two defensin-like peptides derived from red flour beetle (Tribolium castaneum) and human body louse (Pediculus humanus humanus), respectively, exhibited MICs in the range of 13-25 μg/ml against Gram-positive bacteria. Furthermore, HOLO1 showed an MIC less than 5 μg/ml against the fungal species Candida albicans. These peptides exhibited no hemolytic activity at concentrations up to 200 μg/ml. The truncated peptides derived from DAN2 and HOLO1 showed very little antimicrobial activity. Our experiments show that the peptides DAN1, DAN2, HOLO1, and LOUDEF1 showed potent antimicrobial activity in vitro against common human pathogens, did not lyse mammalian red blood cells, and indicates their potential as templates for novel therapeutic agents against microbial infection. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Multipartite entanglement detection with nonsymmetric probing

    DEFF Research Database (Denmark)

    Dellantonio, Luca; Das, Sumanta; Appel, Jürgen

    2017-01-01

    We show that spin-squeezing criteria commonly used for entanglement detection can be erroneous if the probe is not symmetric. We then derive a lower bound on squeezing for separable states in spin systems probed asymmetrically. Using this we further develop a procedure that allows us to verify th...... the degree of entanglement of a quantum state in the spin system. Finally, we apply our method for entanglement verification to existing experimental data, and use it to prove the existence of tripartite entanglement in a spin-squeezed atomic ensemble.......We show that spin-squeezing criteria commonly used for entanglement detection can be erroneous if the probe is not symmetric. We then derive a lower bound on squeezing for separable states in spin systems probed asymmetrically. Using this we further develop a procedure that allows us to verify...

  7. C- and N-truncated antimicrobial peptides from LFampin 265 - 284: Biophysical versus microbiology results

    NARCIS (Netherlands)

    Adão, R.; Nazmi, K.; Bolscher, J.G.M.; Bastos, M.

    2011-01-01

    Lactoferrin is a glycoprotein with two globular lobes, each having two domains. Since the discovery of its antimicrobial properties, efforts have been made to find peptides derived from this protein showing antimicrobial properties. Most peptides initially studied were derived from Lactoferricin B,

  8. Recent studies on the antimicrobial peptides lactoferricin and lactoferrampin.

    Science.gov (United States)

    Yin, C; Wong, J H; Ng, T B

    2014-01-01

    Lactoferricin and lactoferrampin, peptides derived from the whey protein lactoferrin, are antimicrobial agents with a promising prospect and are currently one of the research focuses. In this review, a basic introduction including location and solution structures of these two peptides is given. Their biological activities encompassing antiviral, antibacterial, antifungal and anti-inflammatory activities with possible mechanisms are mentioned. In terms of modification studies, research about identification of their active derivatives and crucial amino acid residues is also discussed. Various attempts at modification of lactoferricin and lactoferrampin such as introducing big hydrophobic side-chains; employing special amino acids for synthesis; N-acetylization, amidation, cyclization and peptide chimera are summarized. The studies on lactoferricin-lactoferrampin chimera are discussed in detail. Future prospects of lactoferricin and lactoferrampin are covered.

  9. Mycobacteria attenuate nociceptive responses by formyl peptide receptor triggered opioid peptide release from neutrophils.

    Directory of Open Access Journals (Sweden)

    Heike L Rittner

    2009-04-01

    Full Text Available In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR and/or toll like receptor (TLR agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively. Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, beta-endorphin antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim

  10. Dynamic PET and SPECT imaging with radioiodinated, amyloid-reactive peptide p5 in mice: a positive role for peptide dehalogenation.

    Science.gov (United States)

    Martin, Emily B; Kennel, Stephen J; Richey, Tina; Wooliver, Craig; Osborne, Dustin; Williams, Angela; Stuckey, Alan; Wall, Jonathan S

    2014-10-01

    Dynamic molecular imaging provides bio-kinetic data that is used to characterize novel radiolabeled tracers for the detection of disease. Amyloidosis is a rare protein misfolding disease that can affect many organs. It is characterized by extracellular deposits composed principally of fibrillar proteins and hypersulfated proteoglycans. We have previously described a peptide, p5, which binds preferentially to amyloid deposits in a murine model of reactive (AA) amyloidosis. We have determined the whole body distribution of amyloid by molecular imaging techniques using radioiodinated p5. The loss of radioiodide from imaging probes due to enzymatic reaction has plagued the use of radioiodinated peptides and antibodies. Therefore, we studied iodine-124-labeled p5 by using dynamic PET imaging of both amyloid-laden and healthy mice to assess the rates of amyloid binding, the relevance of dehalogenation and the fate of the radiolabeled peptide. Rates of blood pool clearance, tissue accumulation and dehalogenation of the peptide were estimated from the images. Comparisons of these properties between the amyloid-laden and healthy mice provided kinetic profiles whose differences may prove to be indicative of the disease state. Additionally, we performed longitudinal SPECT/CT imaging with iodine-125-labeled p5 up to 72h post injection to determine the stability of the radioiodinated peptide when bound to the extracellular amyloid. Our data show that amyloid-associated peptide, in contrast to the unbound peptide, is resistant to dehalogenation resulting in enhanced amyloid-specific imaging. These data further support the utility of this peptide for detecting amyloidosis and monitoring potential therapeutic strategies in patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Enhancing bioactive peptide release and identification using targeted enzymatic hydrolysis of milk proteins.

    Science.gov (United States)

    Nongonierma, Alice B; FitzGerald, Richard J

    2018-06-01

    Milk proteins have been extensively studied for their ability to yield a range of bioactive peptides following enzymatic hydrolysis/digestion. However, many hurdles still exist regarding the widespread utilization of milk protein-derived bioactive peptides as health enhancing agents for humans. These mostly arise from the fact that most milk protein-derived bioactive peptides are not highly potent. In addition, they may be degraded during gastrointestinal digestion and/or have a low intestinal permeability. The targeted release of bioactive peptides during the enzymatic hydrolysis of milk proteins may allow the generation of particularly potent bioactive hydrolysates and peptides. Therefore, the development of milk protein hydrolysates capable of improving human health requires, in the first instance, optimized targeted release of specific bioactive peptides. The targeted hydrolysis of milk proteins has been aided by a range of in silico tools. These include peptide cutters and predictive modeling linking bioactivity to peptide structure [i.e., molecular docking, quantitative structure activity relationship (QSAR)], or hydrolysis parameters [design of experiments (DOE)]. Different targeted enzymatic release strategies employed during the generation of milk protein hydrolysates are reviewed herein and their limitations are outlined. In addition, specific examples are provided to demonstrate how in silico tools may help in the identification and discovery of potent milk protein-derived peptides. It is anticipated that the development of novel strategies employing a range of in silico tools may help in the generation of milk protein hydrolysates containing potent and bioavailable peptides, which in turn may be used to validate their health promoting effects in humans. Graphical abstract The targeted enzymatic hydrolysis of milk proteins may allow the generation of highly potent and bioavailable bioactive peptides.

  12. Conformational Ensembles of α-Synuclein Derived Peptide with Different Osmolytes from Temperature Replica Exchange Sampling

    Directory of Open Access Journals (Sweden)

    Salma Jamal

    2017-12-01

    Full Text Available Intrinsically disordered proteins (IDP are a class of proteins that do not have a stable three-dimensional structure and can adopt a range of conformations playing various vital functional role. Alpha-synuclein is one such IDP which can aggregate into toxic protofibrils and has been associated largely with Parkinson's disease (PD along with other neurodegenerative diseases. Osmolytes are small organic compounds that can alter the environment around the proteins by acting as denaturants or protectants for the proteins. In the present study, we have conducted a series of replica exchange molecular dynamics simulations to explore the role of osmolytes, urea which is a denaturant and TMAO (trimethylamine N-oxide, a protecting osmolyte, in aggregation and conformations of the synuclein peptide. We observed that both the osmolytes have significantly distinct impacts on the peptide and led to transitions of the conformations of the peptide from one state to other. Our findings highlighted that urea attenuated peptide aggregation and resulted in the formation of extended peptide structures whereas TMAO led to compact and folded forms of the peptide.

  13. Milk-derived angiotensin-I-converting enzymeinhibitory peptides generated by Lactobacillus delbrueckii subsp. lactis CRL 581

    Directory of Open Access Journals (Sweden)

    Villegas Josefina M.

    2014-01-01

    Full Text Available Several strains of Lactobacillus helveticus and Lactobacillus delbrueckii subsp. lactis were evaluated for their ability to release angiotensin-I-converting enzyme (ACE inhibitory peptides from α-casein (α-CN and β-casein (β-CN. Casein peptides resulting from L. delbrueckii subsp. lactis CRL 581-mediated hydrolysis exhibited the highest ACE-inhibitory (ACEI activities, with values of 53 and 40% for α-CN and β-CN, respectively. The casein hydrolysates were fractionated by reversedphase high pressure liquid chromatography and some of the active peptides were identified by mass spectrometry. The fraction with the highest ACEI activity arose from β-CN and contained a mixture of the β-CN f194-206 (QEPVLGPVRGPFP and f198-206 (LGPVRGPFP peptides. Furthermore, the ACEI tripeptide IPP was identified in all β-CN hydrolysates; L. delbrueckii subsp. lactis CRL 581 produced the highest amount of this peptide. The bioactive peptides released by CRL 581 strain may be used in the formulation of functional foods and nutraceuticals, representing a healthier and natural alternative for regulating blood pressure.

  14. Development and cytotoxicity of Schiff base derivative as a fluorescence probe for the detection of L-Arginine

    Science.gov (United States)

    Shang, Xuefang; Li, Jie; Guo, Kerong; Ti, Tongyu; Wang, Tianyun; Zhang, Jinlian

    2017-04-01

    Inspired from biological counter parts, chemical modification of Schiff base derivatives with function groups may provide a highly efficient method to detect amino acids. Therefore, a fluorescent probe involving Schiff base and hydroxyl group has been designed and prepared, which showed high response and specificity for Arginine (Arg) among normal eighteen standard kinds of amino acids (Alanine, Valine, Leucine, Isoleucine, Methionine, Asparticacid, Glutamicacid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, the synthesized fluorescent probe exhibited high binding ability for Arg and low cytotoxicity to MCF-7 cells over a concentration range of 0-200 μg mL-1 which can be also used as a biosensor for the Arg detection in vivo.

  15. Structural features governing the activity of lactoferricin-derived peptides that act in synergy with antibiotics against Pseudomonas aeruginosa in vitro and in vivo.

    Science.gov (United States)

    Sánchez-Gómez, Susana; Japelj, Bostjan; Jerala, Roman; Moriyón, Ignacio; Fernández Alonso, Mirian; Leiva, José; Blondelle, Sylvie E; Andrä, Jörg; Brandenburg, Klaus; Lohner, Karl; Martínez de Tejada, Guillermo

    2011-01-01

    Pseudomonas aeruginosa is naturally resistant to many antibiotics, and infections caused by this organism are a serious threat, especially to hospitalized patients. The intrinsic low permeability of P. aeruginosa to antibiotics results from the coordinated action of several mechanisms, such as the presence of restrictive porins and the expression of multidrug efflux pump systems. Our goal was to develop antimicrobial peptides with an improved bacterial membrane-permeabilizing ability, so that they enhance the antibacterial activity of antibiotics. We carried out a structure activity relationship analysis to investigate the parameters that govern the permeabilizing activity of short (8- to 12-amino-acid) lactoferricin-derived peptides. We used a new class of constitutional and sequence-dependent descriptors called PEDES (peptide descriptors from sequence) that allowed us to predict (Spearman's ρ = 0.74; P < 0.001) the permeabilizing activity of a new peptide generation. To study if peptide-mediated permeabilization could neutralize antibiotic resistance mechanisms, the most potent peptides were combined with antibiotics, and the antimicrobial activities of the combinations were determined on P. aeruginosa strains whose mechanisms of resistance to those antibiotics had been previously characterized. A subinhibitory concentration of compound P2-15 or P2-27 sensitized P. aeruginosa to most classes of antibiotics tested and counteracted several mechanisms of antibiotic resistance, including loss of the OprD porin and overexpression of several multidrug efflux pump systems. Using a mouse model of lethal infection, we demonstrated that whereas P2-15 and erythromycin were unable to protect mice when administered separately, concomitant administration of the compounds afforded long-lasting protection to one-third of the animals.

  16. 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...

  17. Preparation and characterization of different liposomal formulations containing P5 HER2/neu-derived peptide and evaluation of their immunological responses and antitumor effects

    Directory of Open Access Journals (Sweden)

    Sheida Shariat

    2015-05-01

    Full Text Available Objective(s:Tumor-associated antigen (TAA subunit-based vaccines constitute promising tools for anticancer immunotherapy. However, a major limitation in the development of such vaccines is the poor immunogenicity of peptides when used alone.The aim of this study was to develop an efficient vaccine delivery system and adjuvant to enhance anti-tumor activity of a synthetic HER2/neu derived peptide (P5. Materials and Methods: P5 peptide was encapsulated with different liposomal formulations composed of DMPC:DMPG:Chol:DOPE and loaded with monophosphoryl lipid A (MPL. All formulations were characterized for their physicochemical properties. To evaluate vaccine efficacy, BALB/c mice were first immunized with free peptide or liposomal formulations, then, inoculated with a subcutaneous injection of TUBO tumor cells. Enzyme-linked immunospot, cytotoxicity and intracellular cytokine assays, as well as tumor size and animal survival analysis, were performed to evaluate the immune responses. Results: The results demonstrated that P5 encapsulated into liposomal formulations was not able to induce CD8 and CD4 T cells to produce IFN-γ. That is why, a potent CTL response and antitumor immunity was not induced. Conclusion: The Lip-DOPE-P5-MPL formulation in spite of using pH-sensitive lipid to direct intracellular trafficking of peptide to MHC I presentation pathway and MPL to enhance peptide adjuvanticity was interesting. The failure in inducing anti-tumor immunity may be attributed to low uptake of anionic conventional liposomes by dendritic cells (DCs that have negative surface charge.

  18. B-Type Natriuretic Peptide: From Posttranslational Processing to Clinical Measurement

    DEFF Research Database (Denmark)

    Goetze, Jens P

    2012-01-01

    BACKGROUND:Plasma cardiac natriuretic peptides and peptide fragments from their molecular precursors are markers of heart disease. Clinical studies have defined the current diagnostic utility of these markers, whereas biochemical elucidation of peptide structure and posttranslational processing has...... pathophysiology and capacity. An ongoing characterization of the molecular heterogeneity may not only help us to appreciate the biosynthetic capacity of the endocrine heart but may also lead to the discovery of new and more disease-specific targets for future molecular diagnosis.SUMMARY:Peptides derived from pro...

  19. Human gut endogenous proteins as a potential source of angiotensin-I-converting enzyme (ACE-I)-, renin inhibitory and antioxidant peptides.

    Science.gov (United States)

    Dave, Lakshmi A; Hayes, Maria; Montoya, Carlos A; Rutherfurd, Shane M; Moughan, Paul J

    2016-02-01

    It is well known that endogenous bioactive proteins and peptides play a substantial role in the body's first line of immunological defence, immune-regulation and normal body functioning. Further, the peptides derived from the luminal digestion of proteins are also important for body function. For example, within the peptide database BIOPEP (http://www.uwm.edu.pl/biochemia/index.php/en/biopep) 12 endogenous antimicrobial and 64 angiotensin-I-converting enzyme (ACE-I) inhibitory peptides derived from human milk and plasma proteins are listed. The antimicrobial peptide database (http://aps.unmc.edu/AP/main.php) lists over 111 human host-defence peptides. Several endogenous proteins are secreted in the gut and are subject to the same gastrointestinal digestion processes as food proteins derived from the diet. The human gut endogenous proteins (GEP) include mucins, serum albumin, digestive enzymes, hormones, and proteins from sloughed off epithelial cells and gut microbiota, and numerous other secreted proteins. To date, much work has been carried out regarding the health altering effects of food-derived bioactive peptides but little attention has been paid to the possibility that GEP may also be a source of bioactive peptides. In this review, we discuss the potential of GEP to constitute a gut cryptome from which bioactive peptides such as ACE-I inhibitory, renin inhibitory and antioxidant peptides may be derived. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Cyclic peptides as potential therapeutic agents for skin disorders.

    Science.gov (United States)

    Namjoshi, Sarika; Benson, Heather A E

    2010-01-01

    There is an increasing understanding of the role of peptides in normal skin function and skin disease. With this knowledge, there is significant interest in the application of peptides as therapeutics in skin disease or as cosmeceuticals to enhance skin appearance. In particular, antimicrobial peptides and those involved in inflammatory processes provide options for the development of new therapeutic directions in chronic skin conditions such as psoriasis and dermatitis. To exploit their potential, it is essential that these peptides are delivered to their site of action in active form and in sufficient quantity to provide the desired effect. Many polymers permeate the skin poorly and are vulnerable to enzymatic degradation. Synthesis of cyclic peptide derivatives can substantially alter the physicochemical characteristics of the peptide with the potential to improve its skin permeation. In addition, cyclization can stabilize the peptide structure and thereby increase its stability. This review describes the role of cyclic peptides in the skin, examples of current cyclic peptide therapeutic products, and the potential for cyclic peptides as dermatological therapeutics and cosmeceuticals.

  1. The synthetic parasite-derived peptide GK1 increases survival in a preclinical mouse melanoma model.

    Science.gov (United States)

    Pérez-Torres, Armando; Vera-Aguilera, Jesús; Hernaiz-Leonardo, Juan Carlos; Moreno-Aguilera, Eduardo; Monteverde-Suarez, Diego; Vera-Aguilera, Carlos; Estrada-Bárcenas, Daniel

    2013-11-01

    The therapeutic efficacy of a synthetic parasite-derived peptide GK1, an immune response booster, was evaluated in a mouse melanoma model. This melanoma model correlates with human stage IIb melanoma, which is treated with wide surgical excision; a parallel study employing a surgical treatment was carried out as an instructive goal. C57BL/6 mice were injected subcutaneously in the flank with 2×10(5) B16-F10 murine melanoma cells. When the tumors reached 20 mm3, mice were separated into two different groups; the GK1 group, treated weekly with peritumoral injections of GK1 (10 μg/100 μL of sterile saline solution) and the control group, treated weekly with an antiseptic peritumoral injection of 100 μL of sterile saline solution without further intervention. All mice were monitored daily for clinical appearance, tumor size, and survival. Surgical treatment was performed in parallel when the tumor size was 20 mm3 (group A), 500 mm3 (group B), and >500 mm3 (group C). The GK1 peptide effectively increased the mean survival time by 9.05 days, corresponding to an increase of 42.58%, and significantly delayed tumor growth from day 3 to 12 of treatment. In addition, tumor necrosis was significantly increased (pcancers remains to be determined, and surgical removal remains a challenge for any new experimental treatment of melanoma in mouse models.

  2. 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.

  3. β-Casein(94-123)-derived peptides differently modulate production of mucins in intestinal goblet cells.

    Science.gov (United States)

    Plaisancié, Pascale; Boutrou, Rachel; Estienne, Monique; Henry, Gwénaële; Jardin, Julien; Paquet, Armelle; Léonil, Joëlle

    2015-02-01

    We recently reported the identification of a peptide from yoghurts with promising potential for intestinal health: the sequence (94-123) of bovine β-casein. This peptide, composed of 30 amino acid residues, maintains intestinal homoeostasis through production of the secreted mucin MUC2 and of the transmembrane-associated mucin MUC4. Our study aimed to search for the minimal sequence responsible for the biological activity of β-CN(94-123) by using several strategies based on (i) known bioactive peptides encrypted in β-CN(94-123), (ii) in silico prediction of peptides reactivity and (iii) digestion of β-CN(94-123) by enzymes of intestinal brush border membranes. The revealed sequences were tested in vitro on human intestinal mucus-producing HT29-MTX cells. We demonstrated that β-CN(108-113) (an ACE-inhibitory peptide) and β-CN(114-119) (an opioid peptide named neocasomorphin-6) up-regulated MUC4 expression whereas levels of the secreted mucins MUC2 and MUC5AC remained unchanged. The digestion of β-CN(94-123) by intestinal enzymes showed that the peptides β-CN(94-108) and β-CN(117-123) were present throughout 1·5 to 3 h of digestion, respectively. These two peptides raised MUC5AC expression while β-CN(117-123) also induced a decrease in the level of MUC2 mRNA and protein. In addition, this inhibitory effect was reproduced in airway epithelial cells. In conclusion, β-CN(94-123) is a multifunctional molecule but only the sequence of 30 amino acids has a stimulating effect on the production of MUC2, a crucial factor of intestinal protection.

  4. Response of electrostatic probes to eccentric charge distributions

    DEFF Research Database (Denmark)

    Johansson, Torben; McAllister, Iain Wilson

    2001-01-01

    The response of an electrostatic probe mounted in an electrode is examined with reference to eccentric charge distributions. The study involves using the probe λ function to derive a characteristic parameter. This parameter enables the response of the probe to different degrees of eccentricity...

  5. A novel fluorescent probe based on rhodamine hydrazone derivatives bearing a thiophene group for Al³⁺.

    Science.gov (United States)

    Li, Meng-xiao; Zhang, Xia; Fan, Yu-hua; Bi, Cai-feng

    2016-05-01

    In the present work, a novel 5-methyl-thiophene-carbaldehyde-functionalized rhodamine 6G Schiff base (RA) was designed and easily prepared as an Al(3+) fluorescent and colorimetric probe, which could selectively and sensitively detect Al(3+) by showing enhanced fluorescence emission. Meanwhile distinct color variation from colorless to pink also provided 'naked eye' detection of Al(3+), due to the ring spirolactam opening of the rhodamine derivative. Other metal ions (including K(+), Mg(2+), Na(+), Ba(2+), Mn(2+), Cd(2+), Fe(2+), Ni(2+), Pb(2+), Zn(2+), Hg(2+), Co(2+), Li(+), Sr(2+) and Cu(2+)) could only induce limited interference. The detection limit of the fluorescent probe was estimated to be 4.17 × 10(-6) M, the binding constant of the RA-Al(3+) complex was 1.4 × 10(6)  M(-1). Moreover, this fluorescent probe RA possessed high reversibility. As aluminum is a ubiquitous metal in nature and plays vital roles in many biological processes, this chemosensor could be explored for biological study applications. Copyright © 2015 John Wiley & Sons, Ltd.

  6. New fluorescent probes of the hydroxyl radical: characterisation and modelization of the reactivity of coumarin derivatives with HO

    International Nuclear Information System (INIS)

    Louit, G.

    2005-10-01

    The hydroxyl radical is involved in a wide range of different fields, from oxidative stress to atmospheric chemistry. In addition to the study of oxidative damage in biological media, the hydroxyl radical detection allows to perform a dosimetry when it is produced by ionising radiation. The aims of this work have been double: - to improve the detection of the hydroxyl radical by the design of new probes - to improve knowledge on the reactive pathways in which the hydroxyl radical is involved. We have studied the coumarin molecule, as well as 6 derivatives that we have synthesised, as fluorescent probes of the hydroxyl radical. Firstly, fluorescence spectroscopy and HPLC chromatography have allowed the evaluation of the sensibility and selectivity of detection of the probes. Consequently to this study, two applications have been developed, concerning the determination of rate constants by competition kinetics and bidimensional dosimetry. Secondly, we have studied the reactivity of the hydroxyl radical through the regioselectivity of its addition on the aromatic cycle. This problem was addressed by the combined use of experimental methods such as time resolved kinetics and HPLC along with interpretation from classical and ab initio modelization. (author)

  7. Lateral flow assay for rapid detection of white spot syndrome virus (WSSV) using a phage-displayed peptide as bio-recognition probe.

    Science.gov (United States)

    Kulabhusan, Prabir Kumar; Rajwade, Jyutika M; Sahul Hameed, A S; Paknikar, Kishore M

    2017-06-01

    White spot disease caused by the white spot syndrome virus (WSSV) has a major socio-economic impact on shrimp farming in India. It has been realized that a field-usable diagnostic capable of rapid detection of WSSV can prevent huge economic losses in disease outbreaks. In this work, we explored the possibility of using a peptide as bio-recognition probe in a field-usable device for the detection of WSSV from infected shrimps and prawns. A commercially available random phage-display library was screened against rVP28 (a major structural protein of WSSV, expressed as a recombinant protein in Escherichia coli). A bacteriophage clone VP28-4L was obtained, and its binding to purified rVP28 protein as well as WSSV from infected shrimp Litopaeneus vannamei tissue was confirmed by ELISA and western blot. The apparent equilibrium dissociation constant (K d ,app) was calculated to be 810 nM. VP28-4L did not show cross-reactivity with any other shrimp viruses. A 12-mer peptide (pep28, with the sequence 'TFQAFDLSPFPS') displayed on the VP28-4L was synthesized, and its diagnostic potential was evaluated in a lateral flow assay (LFA). Visual detection of WSSV could be achieved using biotinylated-pep28 and streptavidin-conjugated gold nanoparticles. In LFA, 12.5 μg/mL of the virus could be detected from L. vannamei gill tissue homogenate within 20 min. Pep28 thus becomes an attractive candidate in bio-recognition of WSSV in field-usable diagnostic platforms benefitting the aquaculture sector.

  8. Immunization of rabbits with synthetic peptides derived from a highly conserved β-sheet epitope region underneath the receptor binding site of influenza A virus

    Directory of Open Access Journals (Sweden)

    Ideno S

    2013-11-01

    Full Text Available Shoji Ideno,1,3 Kaoru Sakai,1 Mikihiro Yunoki,2–4 Ritsuko Kubota-Koketsu,3,5 Yuji Inoue,3 Shota Nakamura,6 Teruo Yasunaga,6 Yoshinobu Okuno,5 Kazuyoshi Ikuta3 1Infectious Pathogen Research Section, Central Research Laboratory, Research and Development Division, Japan Blood Products Organization, Kobe, Japan; 2Research and Development Promotion Section, Research and Development Division, Japan Blood Products Organization, Tokyo, Japan; 3Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; 4Department of Veterinary Microbiology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan; 5Kanonji Institute, The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, Japan; 6Department of Genome Informatics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan Background: There is increasing concern about the speed with which health care providers can administer prophylaxis and treatment in an influenza pandemic. Generally, it takes several months to manufacture an influenza vaccine by propagation of the virus in chicken eggs or cultured cells. Newer, faster protocols for the production of vaccines that induce broad-spectrum immunity are therefore highly desirable. We previously developed human monoclonal antibody B-1 that shows broadly neutralizing activity against influenza A virus H3N2. B-1 recognizes an epitope region that includes an antiparallel β-sheet structure underneath the receptor binding site of influenza hemagglutinin (HA. In this study, the efficacy of a synthetic peptide vaccine derived from this epitope region against influenza A was evaluated. Materials and methods: Two peptides were synthesized, the upper and lower peptides. These peptides comprise amino acid residues 167–187 and 225–241, respectively, of the B-1 epitope region of HA, which is involved in

  9. Peptides Derived from Type IV Collagen, CXC Chemokines, and Thrombospondin-1 Domain-Containing Proteins Inhibit Neovascularization and Suppress Tumor Growth in MDA-MB-231 Breast Cancer Xenografts

    Directory of Open Access Journals (Sweden)

    Jacob E. Koskimaki

    2009-12-01

    Full Text Available Angiogenesis or neovascularization, the process of new blood vessel formation from preexisting microvasculature, involves interactions among several cell types including parenchymal, endothelial cells, and immune cells. The formation of new vessels is tightly regulated by a balance between endogenous proangiogenic and antiangiogenic factors to maintain homeostasis in tissue; tumor progression and metastasis in breast cancer have been shown to be angiogenesis-dependent. We previously introduced a systematic methodology to identify putative endogenous antiangiogenic peptides and validated these predictions in vitro in human umbilical vein endothelial cell proliferation and migration assays. These peptides are derived from several protein families including type IV collagen, CXC chemokines, and thrombospondin-1 domain-containing proteins. On the basis of the results from the in vitro screening, we have evaluated the ability of one peptide selected from each family named pentastatin-1, chemokinostatin-1, and properdistatin, respectively, to suppress angiogenesis in an MDA-MB-231 human breast cancer orthotopic xenograft model in severe combined immunodeficient mice. Peptides were administered intraperitoneally once per day. We have demonstrated significant suppression of tumor growth in vivo and subsequent reductions in microvascular density, indicating the potential of these peptides as therapeutic agents for breast cancer.

  10. Incorporating TiO2 nanotubes with a peptide of D-amino K122-4 (D) for enhanced mechanical and photocatalytic properties

    Science.gov (United States)

    Guo, L. Q.; Hu, Y. W.; Yu, B.; Davis, E.; Irvin, R.; Yan, X. G.; Li, D. Y.

    2016-02-01

    Titanium dioxide (TiO2) nanotubes are promising for a wide variety of potential applications in energy, biomedical and environmental sectors. However, their low mechanical strength and wide band gap limit their widespread technological use. This article reports our recent efforts to increase the mechanical strength of TiO2 nanotubes with lowered band gap by immobilizing a peptide of D-amino K122-4 (D) onto the nanotubes. Topographies and chemical compositions of the peptide-coated and uncoated TiO2 nanotubular arrays were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS). Properties of the peptide-coated and uncoated TiO2 nanotubular arrays, including hardness, elastic modulus, electron work function and photocurrent, were evaluated using micromechanical probe, Kelvin Probe and electrochemical system. Effect of the peptide on surface conductivity was also investigated through current mapping and I-V curve analysis with conductive atomic force microscopy. It is demonstrated that the peptide coating simultaneously enhances the mechanical strength, photocatalytic and electrical properties of TiO2 nanotubes.

  11. Anxiety, Depression, and the Microbiome: A Role for Gut Peptides.

    Science.gov (United States)

    Lach, Gilliard; Schellekens, Harriet; Dinan, Timothy G; Cryan, John F

    2018-01-01

    The complex bidirectional communication between the gut and the brain is finely orchestrated by different systems, including the endocrine, immune, autonomic, and enteric nervous systems. Moreover, increasing evidence supports the role of the microbiome and microbiota-derived molecules in regulating such interactions; however, the mechanisms underpinning such effects are only beginning to be resolved. Microbiota-gut peptide interactions are poised to be of great significance in the regulation of gut-brain signaling. Given the emerging role of the gut-brain axis in a variety of brain disorders, such as anxiety and depression, it is important to understand the contribution of bidirectional interactions between peptide hormones released from the gut and intestinal bacteria in the context of this axis. Indeed, the gastrointestinal tract is the largest endocrine organ in mammals, secreting dozens of different signaling molecules, including peptides. Gut peptides in the systemic circulation can bind cognate receptors on immune cells and vagus nerve terminals thereby enabling indirect gut-brain communication. Gut peptide concentrations are not only modulated by enteric microbiota signals, but also vary according to the composition of the intestinal microbiota. In this review, we will discuss the gut microbiota as a regulator of anxiety and depression, and explore the role of gut-derived peptides as signaling molecules in microbiome-gut-brain communication. Here, we summarize the potential interactions of the microbiota with gut hormones and endocrine peptides, including neuropeptide Y, peptide YY, pancreatic polypeptide, cholecystokinin, glucagon-like peptide, corticotropin-releasing factor, oxytocin, and ghrelin in microbiome-to-brain signaling. Together, gut peptides are important regulators of microbiota-gut-brain signaling in health and stress-related psychiatric illnesses.

  12. Recognition of Core- and Polymerase-derived immunogenic peptides included in novel therapeutic vaccine by T cells from Chinese chronic hepatitis B patients.

    Science.gov (United States)

    Huang, D; Sansas, B; Jiang, J H; Gong, Q M; Jin, G D; Calais, V; Yu, D M; Zhu, M Y; Wei, D; Zhang, D H; Inchauspé, G; Zhang, X X; Zhu, R

    2017-11-01

    Chronic hepatitis B (CHB) is one of the major public health challenges in the world. Due to a strong interplay between specific T-cell immunity and elimination of hepatitis B virus (HBV), efforts to develop novel immunotherapeutics are gaining attention. TG1050, a novel immunotherapy, has shown efficacy in an animal study. To support the clinical development of TG1050 in China, specific immunity to the fusion antigens of TG1050 was assessed in Chinese patients. One hundred and thirty subjects were divided into three groups as CHB patients, HBV spontaneous resolvers, and CHB patients with HBsAg loss after antiviral treatment. HBV-specific T-cell responses to pools of HBV Core or Polymerase genotype D peptides included in TG1050 were evaluated. HBV Core- or Polymerase-specific cells were detected in peripheral blood mononuclear cells (PBMCs) from the different cohorts. The frequencies and intensities of HBV Core-specific immune responses were significantly lower in CHB patients than in HBsAg loss subjects. In CHB patients, a dominant pool derived from Polymerase (Pol1) was the most immunogenic. CHB patients with low viral loads (Core peptide pool. Overall, genotype D-derived peptides included in TG1050 could raise broad and functional T-cell responses in PBMCs from Chinese CHB patients infected with genotype B/C isolates. Core-specific immunogenic domains appeared as "hot spots" with the capacity to differentiate between CHB vs HBsAg loss subjects. These observations support the extended application and associated immune monitoring of TG1050 in China. © 2017 The Authors. Journal of Viral Hepatitis Published by John Wiley & Sons Ltd.

  13. Pharmacological screening technologies for venom peptide discovery.

    Science.gov (United States)

    Prashanth, Jutty Rajan; Hasaballah, Nojod; Vetter, Irina

    2017-12-01

    Venomous animals occupy one of the most successful evolutionary niches and occur on nearly every continent. They deliver venoms via biting and stinging apparatuses with the aim to rapidly incapacitate prey and deter predators. This has led to the evolution of venom components that act at a number of biological targets - including ion channels, G-protein coupled receptors, transporters and enzymes - with exquisite selectivity and potency, making venom-derived components attractive pharmacological tool compounds and drug leads. In recent years, plate-based pharmacological screening approaches have been introduced to accelerate venom-derived drug discovery. A range of assays are amenable to this purpose, including high-throughput electrophysiology, fluorescence-based functional and binding assays. However, despite these technological advances, the traditional activity-guided fractionation approach is time-consuming and resource-intensive. The combination of screening techniques suitable for miniaturization with sequence-based discovery approaches - supported by advanced proteomics, mass spectrometry, chromatography as well as synthesis and expression techniques - promises to further improve venom peptide discovery. Here, we discuss practical aspects of establishing a pipeline for venom peptide drug discovery with a particular emphasis on pharmacology and pharmacological screening approaches. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.' Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Meat and fermented meat products as a source of bioactive peptides.

    Science.gov (United States)

    Stadnik, Joanna; Kęska, Paulina

    2015-01-01

    Bioactive peptides are short amino acid sequences, that upon release from the parent protein may play different physiological roles, including antioxidant, antihypertensive, antimicrobial, and other bioactivities. They have been identified from a range of foods, including those of animal origin, e.g., milk and muscle sources (with pork, beef, or chicken and various species of fish and marine organism). Bioactive peptides are encrypted within the sequence of the parent protein molecule and latent until released and activated by enzymatic proteolysis, e.g. during gastrointestinal digestion or food processing. Bioactive peptides derived from food sources have the potential for incorporation into functional foods and nutraceuticals. The aim of this paper is to present an overview of the muscle-derived bioactive peptides, especially those of fermented meats and the potential benefits of these bioactive compounds to human health.

  15. Biologically Active and Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    Carlos E. Salas

    2015-01-01

    Full Text Available Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application.

  16. Biologically Active and Antimicrobial Peptides from Plants

    Science.gov (United States)

    Salas, Carlos E.; Badillo-Corona, Jesus A.; Ramírez-Sotelo, Guadalupe; Oliver-Salvador, Carmen

    2015-01-01

    Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application. PMID:25815307

  17. The Utility of Ovotransferrin and Ovotransferrin-Derived Peptides as Possible Candidates in the Clinical Treatment of Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Shuang Chen

    2017-01-01

    Full Text Available Several of the most prevalent etiological factors which contribute towards global death rates are associated with cardiovascular diseases (CVDs, which include a range of conditions such as angina, rheumatic heart disease, and venous thrombosis. Extensive research has been conducted into the role played by oxidative stress and inflammation in the functional transformations associated with the progression of CVDs, while the research findings from these investigations have been both fruitful and informative. In view of the adverse secondary effects that result from the clinical administration of many synthetic medications, research which explored the treatment of severe and long-lasting conditions, including CVDs, has primarily centered on the potential benefits displayed by natural agents, one of which is food protein-based bioactive peptides. Most importantly, previous research has revealed the possible benefits associated with these products’ anti-inflammatory and antioxidant characteristics. In light of these considerations, this paper aims to review the degree to which ovotransferrin (otrf, also referred to as conalbumin and otrf-derived peptides, including IRW, IQW, and KVREGT, are, by virtue of their anti-inflammatory and antioxidant characteristics, viable treatment agents for endothelial dysfunction and the prevention of CVD.

  18. Frequency of and Prognostic Significance of Cardiac Involvement at Presentation in Hereditary Transthyretin-Derived Amyloidosis and the Value of N-Terminal Pro-B-Type Natriuretic Peptide

    NARCIS (Netherlands)

    Klaassen, Sebastiaan H C; Tromp, Jasper; Nienhuis, Hans L A; van der Meer, Peter; van den Berg, Maarten P; Blokzijl, Hans; van Veldhuisen, Dirk J; Hazenberg, Bouke P C

    2018-01-01

    The aim of this study is to assess the prevalence of cardiac involvement in hereditary transthyretin-derived (ATTRm) amyloidosis at the time of diagnosis and to determine the diagnostic and clinical value of N-terminal pro-B-type natriuretic peptide (NT-proBNP). The University Medical Center

  19. Electron transfer dissociation facilitates the measurement of deuterium incorporation into selectively labeled peptides with single residue resolution

    DEFF Research Database (Denmark)

    Zehl, Martin; Rand, Kasper D; Jensen, Ole N

    2008-01-01

    Mass spectrometry is routinely applied to measure the incorporation of deuterium into proteins and peptides. The exchange of labile, heteroatom-bound hydrogens is mainly used to probe the structural dynamics of proteins in solution, e.g., by hydrogen-exchange mass spectrometry, but also to study...... collisional activation induces proton mobility in a gaseous peptide ion at various levels of vibrational excitation....

  20. Anti-Mycobacterial Peptides: From Human to Phage

    Directory of Open Access Journals (Sweden)

    Tieshan Teng

    2015-01-01

    Full Text Available Mycobacterium tuberculosis is the major pathogen of tuberculosis (TB. With the growing problem of M. tuberculosis resistant to conventional antibiotics, especially multi-drug resistant tuberculosis (MDR-TB and extensively-drug resistant tuberculosis (XDR-TB, the need for new TB drugs is now more prominent than ever. Among the promising candidates for anti-TB drugs, anti-mycobacterial peptides have a few advantages, such as low immunogenicity, selective affinity to prokaryotic negatively charged cell envelopes, and diverse modes of action. In this review, we summarize the recent progress in the anti-mycobacterial peptides, highlighting the sources, effectiveness and bactericidal mechanisms of these antimicrobial peptides. Most of the current anti-mycobacterial peptides are derived either from host immune cells, bacterial extraction, or mycobacteriophages. Besides trans-membrane pore formation, which is considered to be the common bactericidal mechanism, many of the anti-mycobacterial peptides have the second non-membrane targets within mycobacteria. Additionally, some antimicrobial peptides play critical roles in innate immunity. However, a few obstacles, such as short half-life in vivo and resistance to antimicrobial peptides, need overcoming before clinical applications. Nevertheless, the multiple functions of anti-mycobacterial peptides, especially direct killing of pathogens and immune-modulators in infectious and inflammatory conditions, indicate that they are promising candidates for future drug development.

  1. [Development of a Fluorescence Probe for Live Cell Imaging].

    Science.gov (United States)

    Shibata, Aya

    2017-01-01

    Probes that detect specific biological materials are indispensable tools for deepening our understanding of various cellular phenomena. In live cell imaging, the probe must emit fluorescence only when a specific substance is detected. In this paper, we introduce a new probe we developed for live cell imaging. Glutathione S-transferase (GST) activity is higher in tumor cells than in normal cells and is involved in the development of resistance to various anticancer drugs. We previously reported the development of a general strategy for the synthesis of probes for detection of GST enzymes, including fluorogenic, bioluminogenic, and 19 F-NMR probes. Arylsulfonyl groups were used as caging groups during probe design. The fluorogenic probes were successfully used to quantitate very low levels of GST activity in cell extracts and were also successfully applied to the imaging of microsomal MGST1 activity in living cells. The bioluminogenic and 19 F-NMR probes were able to detect GST activity in Escherichia coli cells. Oligonucleotide-templated reactions are powerful tools for nucleic acid sensing. This strategy exploits the target strand as a template for two functionalized probes and provides a simple molecular mechanism for multiple turnover reactions. We developed a nucleophilic aromatic substitution reaction-triggered fluorescent probe. The probe completed its reaction within 30 s of initiation and amplified the fluorescence signal from 0.5 pM target oligonucleotide by 1500 fold under isothermal conditions. Additionally, we applied the oligonucleotide-templated reaction for molecular releasing and peptide detection.

  2. Peptides in headlock--a novel high-affinity and versatile peptide-binding nanobody for proteomics and microscopy.

    Science.gov (United States)

    Braun, Michael B; Traenkle, Bjoern; Koch, Philipp A; Emele, Felix; Weiss, Frederik; Poetz, Oliver; Stehle, Thilo; Rothbauer, Ulrich

    2016-01-21

    Nanobodies are highly valuable tools for numerous bioanalytical and biotechnical applications. Here, we report the characterization of a nanobody that binds a short peptide epitope with extraordinary affinity. Structural analysis reveals an unusual binding mode where the extended peptide becomes part of a β-sheet structure in the nanobody. This interaction relies on sequence-independent backbone interactions augmented by a small number of specificity-determining side chain contacts. Once bound, the peptide is fastened by two nanobody side chains that clamp it in a headlock fashion. Exploiting this unusual binding mode, we generated a novel nanobody-derived capture and detection system. Matrix-coupled nanobody enables the fast and efficient isolation of epitope-tagged proteins from prokaryotic and eukaryotic expression systems. Additionally, the fluorescently labeled nanobody visualizes subcellular structures in different cellular compartments. The high-affinity-binding and modifiable peptide tag of this system renders it a versatile and robust tool to combine biochemical analysis with microscopic studies.

  3. Biophysical and biological properties of small linear peptides derived from crotamine, a cationic antimicrobial/antitumoral toxin with cell penetrating and cargo delivery abilities.

    Science.gov (United States)

    Dal Mas, C; Pinheiro, D A; Campeiro, J D; Mattei, B; Oliveira, V; Oliveira, E B; Miranda, A; Perez, K R; Hayashi, M A F

    2017-12-01

    Crotamine is a natural polypeptide from snake venom which delivers nucleic acid molecules into cells, besides having pronounced affinity for negatively charged membranes and antifungal activity. We previously demonstrated that crotamine derived short linear peptides were not very effective as antifungal, although the non-structured recombinant crotamine was overridingly more potent compared to the native structured crotamine. Aiming to identify the features necessary for the antifungal activity of crotamine, two linear short peptides, each comprising half of the total positively charged amino acid residues of the full-length crotamine were evaluated here to show that these linear peptides keep the ability to interact with lipid membrane model systems with different phospholipid compositions, even after forming complexes with DNA. Interestingly, the presence of cysteine residues in the structure of these linear peptides highly influenced the antifungal activity, which was not associated to the lipid membrane lytic activity. In addition to the importance of the positive charges, the crucial role of cysteine residues was noticed for these linear analogs of crotamine, although the tridimensional structure and lipid membrane lytic activity observed only for native crotamine was not essential for the antifungal activity. As these peptides still keep the ability to form complexes with DNA molecules with no prejudice to their ability to bind to lipid membranes, they may be potentially advantageous as membrane translocation vector, as they do not show lipid membrane lytic activity and may harbor or not antifungal activity, by keeping or not the semi-essential amino acid cysteine in their sequence. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Homing peptide guiding optical molecular imaging for the diagnosis of bladder cancer

    Science.gov (United States)

    Yang, Xiao-feng; Pang, Jian-zhi; Liu, Jie-hao; Zhao, Yang; Jia, Xing-you; Li, Jun; Liu, Reng-xin; Wang, Wei; Fan, Zhen-wei; Zhang, Zi-qiang; Yan, San-hua; Luo, Jun-qian; Zhang, Xiao-lei

    2014-11-01

    Background: The limitations of primary transurethral resection of bladder tumor (TURBt) have led the residual tumors rates as high as 75%. The intraoperative fluorescence imaging offers a great potential for improving TURBt have been confirmed. So we aim to distinguish the residual tumors and normal mucosa using fluorescence molecular imaging formed by conjugated molecule of the CSNRDARRC bladder cancer homing peptide with fluorescent dye. The conjugated molecule was abbreviated FIuo-ACP. In our study, we will research the image features of FIuo-ACP probe targeted bladder cancer for fluorescence molecular imaging diagnosis for bladder cancer in vivo and ex vivo. Methods: After the FIuo-ACP probe was synthetized, the binding sites, factors affecting binding rates, the specificity and the targeting of Fluo-ACP labeled with bladder cancer cells were studied respectively by laser scanning confocal microscope (LSCM), immunofluorescence and multispectral fluorescence ex vivo optical molecular imaging system. Results: The binding sites were located in nucleus and the binding rates were correlated linearly with the dose of probe and the grade of pathology. Moreover, the probe has a binding specificity with bladder cancer in vivo and ex vivo. Tumor cells being labeled by the Fluo-ACP, bright green spots were observed under LSCM. The tissue samples and tumor cells can be labeled and identified by fluorescence microscope. Optical molecular imaging of xenograft tumor tissues was exhibited as fluorescent spots under EMCCD. Conclusion: The CSNRDARRC peptides might be a useful bladder cancer targeting vector. The FIuo-ACP molecular probe was suitable for fluorescence molecular imaging diagnosis for bladder cancer in vivo and ex vivo.

  5. Synthesis and functional evaluation of a peptide derivative of 1-beta-D-arabinofuranosylcytosine.

    Science.gov (United States)

    Balajthy, Z; Aradi, J; Kiss, I T; Elödi, P

    1992-09-04

    We have synthesized a peptidyl prodrug derivative of 1-beta-D-arabinofuranosylcytosine (1) designed to be a selective substrate of plasmin. D-Val-Leu-Lys-ara-C (2) was obtained by coupling the protected peptide Cbz-D-Val-Leu-(N6-Cbz)Lys-OH and ara-C (1) by a water-soluble carbodiimide (EDCI), followed by the removal of the Cbz groups by using catalytic hydrogenolysis over Pd/C. The kinetic constant of hydrolysis of 2 in the presence of plasmin demonstrated effective release of 1. The amino group of 1, which is sensitive to the removal by cytidine deaminase, is protected in 2 by the formation of the amide bond resulting in a prolonged half-life of 2 in biological milieu. The antiproliferative efficiency of 2 against L1210 leukemic cells was significantly higher than that of 1. The activity of 2 was abolished in the presence of serine proteinase inhibitor, (4-amidinopheny)methanesulfonyl fluoride. These data indicate that 2 is a prodrug form of 1 in systems generating plasmin.

  6. Expression and characterization of preproVIP derived peptides in the human male urogenital tract

    DEFF Research Database (Denmark)

    Ottesen, B; Bredkjaer, H E; Ekblad, E

    1995-01-01

    Expression of the gene sequence encoding vasoactive intestinal polypeptide (VIP) leads to the synthesis of a 170 amino acid precursor molecule which can be processed to five fragments: preproVIP 22-79, peptide histidine methionine (PHM), or peptide histidine valine (PHV), preproVIP 111-122, VIP...

  7. Comparative analysis of human milk and infant formula derived peptides following in vitro digestion.

    Science.gov (United States)

    Su, M-Y; Broadhurst, M; Liu, C-P; Gathercole, J; Cheng, W-L; Qi, X-Y; Clerens, S; Dyer, J M; Day, L; Haigh, B

    2017-04-15

    It has long been recognised that there are differences between human milk and infant formulas which lead to differences in health and nutrition for the neonate. In this study we examine and compare the peptide profile of human milk and an exemplar infant formula. The study identifies both similarities and differences in the endogenous and postdigestion peptide profiles of human milk and infant formula. This includes differences in the protein source of these peptides but also with the region within the protein producing the dominant proteins. Clustering of similar peptides around regions of high sequence identity and known bioactivity was also observed. Together the data may explain some of the functional differences between human milk and infant formula, while identifying some aspects of conserved function between bovine and human milks which contribute to the effectiveness of modern infant formula as a substitute for human milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Dinosaur peptides suggest mechanisms of protein survival.

    Science.gov (United States)

    San Antonio, James D; Schweitzer, Mary H; Jensen, Shane T; Kalluri, Raghu; Buckley, Michael; Orgel, Joseph P R O

    2011-01-01

    Eleven collagen peptide sequences recovered from chemical extracts of dinosaur bones were mapped onto molecular models of the vertebrate collagen fibril derived from extant taxa. The dinosaur peptides localized to fibril regions protected by the close packing of collagen molecules, and contained few acidic amino acids. Four peptides mapped to collagen regions crucial for cell-collagen interactions and tissue development. Dinosaur peptides were not represented in more exposed parts of the collagen fibril or regions mediating intermolecular cross-linking. Thus functionally significant regions of collagen fibrils that are physically shielded within the fibril may be preferentially preserved in fossils. These results show empirically that structure-function relationships at the molecular level could contribute to selective preservation in fossilized vertebrate remains across geological time, suggest a 'preservation motif', and bolster current concepts linking collagen structure to biological function. This non-random distribution supports the hypothesis that the peptides are produced by the extinct organisms and suggests a chemical mechanism for survival.

  9. Dinosaur Peptides Suggest Mechanisms of Protein Survival

    Energy Technology Data Exchange (ETDEWEB)

    San Antonio, James D.; Schweitzer, Mary H.; Jensen, Shane T.; Kalluri, Raghu; Buckley, Michael; Orgel, Joseph P.R.O. (Harvard-Med); (IIT); (NCSU); (UPENN); (Manchester); (Orthovita)

    2011-09-16

    Eleven collagen peptide sequences recovered from chemical extracts of dinosaur bones were mapped onto molecular models of the vertebrate collagen fibril derived from extant taxa. The dinosaur peptides localized to fibril regions protected by the close packing of collagen molecules, and contained few acidic amino acids. Four peptides mapped to collagen regions crucial for cell-collagen interactions and tissue development. Dinosaur peptides were not represented in more exposed parts of the collagen fibril or regions mediating intermolecular cross-linking. Thus functionally significant regions of collagen fibrils that are physically shielded within the fibril may be preferentially preserved in fossils. These results show empirically that structure-function relationships at the molecular level could contribute to selective preservation in fossilized vertebrate remains across geological time, suggest a 'preservation motif', and bolster current concepts linking collagen structure to biological function. This non-random distribution supports the hypothesis that the peptides are produced by the extinct organisms and suggests a chemical mechanism for survival.

  10. Structural Features Governing the Activity of Lactoferricin-Derived Peptides That Act in Synergy with Antibiotics against Pseudomonas aeruginosa In Vitro and In Vivo▿ †

    Science.gov (United States)

    Sánchez-Gómez, Susana; Japelj, Bostjan; Jerala, Roman; Moriyón, Ignacio; Fernández Alonso, Mirian; Leiva, José; Blondelle, Sylvie E.; Andrä, Jörg; Brandenburg, Klaus; Lohner, Karl; Martínez de Tejada, Guillermo

    2011-01-01

    Pseudomonas aeruginosa is naturally resistant to many antibiotics, and infections caused by this organism are a serious threat, especially to hospitalized patients. The intrinsic low permeability of P. aeruginosa to antibiotics results from the coordinated action of several mechanisms, such as the presence of restrictive porins and the expression of multidrug efflux pump systems. Our goal was to develop antimicrobial peptides with an improved bacterial membrane-permeabilizing ability, so that they enhance the antibacterial activity of antibiotics. We carried out a structure activity relationship analysis to investigate the parameters that govern the permeabilizing activity of short (8- to 12-amino-acid) lactoferricin-derived peptides. We used a new class of constitutional and sequence-dependent descriptors called PEDES (peptide descriptors from sequence) that allowed us to predict (Spearman's ρ = 0.74; P < 0.001) the permeabilizing activity of a new peptide generation. To study if peptide-mediated permeabilization could neutralize antibiotic resistance mechanisms, the most potent peptides were combined with antibiotics, and the antimicrobial activities of the combinations were determined on P. aeruginosa strains whose mechanisms of resistance to those antibiotics had been previously characterized. A subinhibitory concentration of compound P2-15 or P2-27 sensitized P. aeruginosa to most classes of antibiotics tested and counteracted several mechanisms of antibiotic resistance, including loss of the OprD porin and overexpression of several multidrug efflux pump systems. Using a mouse model of lethal infection, we demonstrated that whereas P2-15 and erythromycin were unable to protect mice when administered separately, concomitant administration of the compounds afforded long-lasting protection to one-third of the animals. PMID:20956602

  11. Biodegradable copolymers carrying cell-adhesion peptide sequences.

    Science.gov (United States)

    Proks, Vladimír; Machová, Lud'ka; Popelka, Stepán; Rypácek, Frantisek

    2003-01-01

    Amphiphilic block copolymers are used to create bioactive surfaces on biodegradable polymer scaffolds for tissue engineering. Cell-selective biomaterials can be prepared using copolymers containing peptide sequences derived from extracellular-matrix proteins (ECM). Here we discuss alternative ways for preparation of amphiphilic block copolymers composed of hydrophobic polylactide (PLA) and hydrophilic poly(ethylene oxide) (PEO) blocks with cell-adhesion peptide sequences. Copolymers PLA-b-PEO were prepared by a living polymerisation of lactide in dioxane with tin(II)2-ethylhexanoate as a catalyst. The following approaches for incorporation of peptides into copolymers were elaborated. (a) First, a side-chain protected Gly-Arg-Gly-Asp-Ser-Gly (GRGDSG) peptide was prepared by solid-phase peptide synthesis (SPPS) and then coupled with delta-hydroxy-Z-amino-PEO in solution. In the second step, the PLA block was grafted to it via a controlled polymerisation of lactide initiated by the hydroxy end-groups of PEO in the side-chain-protected GRGDSG-PEO. Deprotection of the peptide yielded a GRGDSG-b-PEO-b-PLA copolymer, with the peptide attached through its C-end. (b) A protected GRGDSG peptide was built up on a polymer resin and coupled with Z-carboxy-PEO using a solid-phase approach. After cleavage of the delta-hydroxy-PEO-GRGDSG copolymer from the resin, polymerisation of lactide followed by deprotection of the peptide yielded a PLA-b-PEO-b-GRGDSG block copolymer, in which the peptide is linked through its N-terminus.

  12. P5 HER2/neu-derived peptide conjugated to liposomes containing MPL adjuvant as an effective prophylactic vaccine formulation for breast cancer.

    Science.gov (United States)

    Shariat, Sheida; Badiee, Ali; Jalali, Seyed Amir; Mansourian, Mercedeh; Yazdani, Mona; Mortazavi, Seyed Alireza; Jaafari, Mahmoud Reza

    2014-12-01

    Vaccines containing synthetic peptides derived from tumor-associated antigens (TAA) can elicit potent cytotoxic T lymphocyte (CTL) response if they are formulated in an optimal vaccine delivery system. The aim of this study was to develop a simple and effective lipid-based vaccine delivery system using P5 HER2/neu-derived peptide conjugated to Maleimide-PEG2000-DSPE. The conjugated lipid was then incorporated into liposomes composed of DMPC:DMPG:Chol:DOPE containing Monophosphoryl lipid A (MPL) (Lip-DOPE-P5-MPL). Different liposome formulations were prepared and characterized for their physicochemical properties. To evaluate anti-tumoral efficacy, BALB/c mice were immunized subcutaneously 3 times in two-week intervals and the generated immune response was studied. The results demonstrated that Lip-DOPE-P5-MPL induced a significantly higher IFN-γ production by CD8+ T cells intracellularly which represents higher CTL response in comparison with other control formulations. CTL response induced by this formulation caused the lowest tumor size and the longest survival time in a mice model of TUBO tumor. The encouraging results achieved by Lip-DOPE-P5-MPL formulation could make it a promising candidate in developing effective vaccines against Her2 positive breast cancers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Factors affecting antimicrobial activity of MUC7 12-mer, a human salivary mucin-derived peptide

    Directory of Open Access Journals (Sweden)

    Bobek Libuse A

    2007-11-01

    Full Text Available Abstract Background MUC7 12-mer (RKSYKCLHKRCR, a cationic antimicrobial peptide derived from the human low-molecular-weight salivary mucin MUC7, possesses potent antimicrobial activity in vitro. In order to evaluate the potential therapeutic application of the MUC7 12-mer, we examined the effects of mono- and divalent cations, EDTA, pH, and temperature on its antimicrobial activity. Methods Minimal Inhibitory Concentrations (MICs were determined using a liquid growth inhibition assay in 96-well microtiter plates. MUC7 12-mer was added at concentrations of 1.56–50 μM. MICs were determined at three endpoints: MIC-0, MIC-1, and MIC-2 (the lowest drug concentration showing 10%, 25% and 50% of growth, respectively. To examine the effect of salts or EDTA, a checkerboard microdilution technique was used. Fractional inhibitory concentration index (FICi was calculated on the basis of MIC-0. The viability of microbial cells treated with MUC7 12-mer in the presence of sodium or potassium was also determined by killing assay or flow cytometry. Results The MICs of MUC7 12-mer against organisms tested ranged from 6.25–50 μM. For C. albicans, antagonism (FICi 4.5 was observed for the combination of MUC7 12-mer and calcium; however, there was synergism (FICi 0.22 between MUC7 12-mer and EDTA, and the synergism was retained in the presence of calcium at its physiological concentration (1–2 mM. No antagonism but additivity or indifference (FICi 0.55–2.5 was observed for the combination of MUC7 12-mer and each K+, Na+, Mg2+, or Zn2+. MUC7 12-mer peptide (at 25 μM also exerted killing activity in the presence of NaCl, (up to 25 mM for C. albicans and up to 150 mM for E. coli, a physiological concentration of sodium in the oral cavity and serum, respectively and retained candidacidal activity in the presence of KCl (up to 40 mM. The peptide exhibited higher inhibitory activity against C. albicans at pH 7, 8, and 9 than at pH 5 and 6, and temperature up to

  14. Intramolecular migration of amide hydrogens in protonated peptides upon collisional activation

    DEFF Research Database (Denmark)

    Jørgensen, Thomas J. D.; Gårdsvoll, H.; Ploug, M.

    2005-01-01

    Presently different opinions exist as to the degree of scrambling of amide hydrogens in gaseous protonated peptides and proteins upon collisional activation in tandem mass spectrometry experiments. This unsettled controversy is not trivial, since only a very low degree of scrambling is tolerable...... if collision-induced dissociation (CID) should provide reliable site-specific information from (1)H/(2)H exchange experiments. We have explored a series of unique, regioselectively deuterium-labeled peptides as model systems to probe for intramolecular amide hydrogen migration under low-energy collisional...... are protected against exchange with the solvent, while the amide hydrogens of the nonbinding sequences exchange rapidly with the solvent. We have utilized such long-lived complexes to generate peptides labeled with deuterium in either the binding or nonbinding region, and the expected regioselectivity...

  15. Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-99m.

    Science.gov (United States)

    Fuscaldi, Leonardo Lima; Dos Santos, Daniel Moreira; Pinheiro, Natália Gabriela Silva; Araújo, Raquel Silva; de Barros, André Luís Branco; Resende, Jarbas Magalhães; Fernandes, Simone Odília Antunes; de Lima, Maria Elena; Cardoso, Valbert Nascimento

    2016-01-01

    Current diagnostic methods and imaging techniques are not able to differentiate septic and aseptic inflammation. Thus, reliable methods are sought to provide this distinction and scintigraphic imaging is an interesting option, since it is based on physiological changes. In this context, radiolabeled antimicrobial peptides have been investigated as they accumulate in infectious sites instead of aseptic inflammation. The peptide LyeTx I, from the venom of Lycosa erythrognatha, has potent antimicrobial activity. Therefore, this study aimed to synthesize LyeTx I derivatives with the chelating compound HYNIC, to evaluate their antimicrobial activity and to radiolabel them with (99m)Tc. Two LyeTx I derivatives, HYNIC-LyeTx I (N-terminal modification) and LyeTx I-K-HYNIC (C-terminal modification), were synthesized by Fmoc strategy and purified by RP-HPLC. The purified products were assessed by RP-HPLC and MALDI-ToF-MS analysis. Microbiological assays were performed against S. aureus (ATCC® 6538) and E. coli (ATCC® 10536) in liquid medium to calculate the MIC. The radiolabeling procedure of LyeTx I-K-HYNIC with (99m)Tc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl2 (.) 2H2O), and standardized taking into account the amount of peptide, reducing agent, pH and heating. Radiochemical purity analysis was performed by thin-layer chromatography on silica gel strips and the radiolabeled compound was assessed by RP-HPLC and radioactivity measurement of the collected fractions. Data were analyzed by ANOVA, followed by Tukey test (p-values EDDA). The binding of HYNIC to the N-terminal portion of LyeTx I seems to affect its activity against bacteria. Nevertheless, the radiolabeling of the C-terminal derivative, LyeTx I-K-HYNIC, must be better investigated to optimize the radiolabeled compound, in order to use it as a specific imaging agent to distinguish septic and aseptic inflammation.

  16. Lipopolysaccharide interactions of C-terminal peptides from human thrombin.

    Science.gov (United States)

    Singh, Shalini; Kalle, Martina; Papareddy, Praveen; Schmidtchen, Artur; Malmsten, Martin

    2013-05-13

    Interactions with bacterial lipopolysaccharide (LPS), both in aqueous solution and in lipid membranes, were investigated for a series of amphiphilic peptides derived from the C-terminal region of human thrombin, using ellipsometry, dual polarization interferometry, fluorescence spectroscopy, circular dichroism (CD), dynamic light scattering, and z-potential measurements. The ability of these peptides to block endotoxic effects caused by LPS, monitored through NO production in macrophages, was compared to peptide binding to LPS and its endotoxic component lipid A, and to size, charge, and secondary structure of peptide/LPS complexes. While the antiendotoxic peptide GKY25 (GKYGFYTHVFRLKKWIQKVIDQFGE) displayed significant binding to both LPS and lipid A, so did two control peptides with either selected D-amino acid substitutions or with maintained composition but scrambled sequence, both displaying strongly attenuated antiendotoxic effects. Hence, the extent of LPS or lipid A binding is not the sole discriminant for the antiendotoxic effect of these peptides. In contrast, helix formation in peptide/LPS complexes correlates to the antiendotoxic effect of these peptides and is potentially linked to this functionality. Preferential binding to LPS over lipid membrane was furthermore demonstrated for these peptides and preferential binding to the lipid A moiety within LPS inferred.

  17. The milk-derived peptides Val-Pro-Pro and Ile-Pro-Pro attenuate arterial dysfunction in L-NAME-treated rats.

    Science.gov (United States)

    Nonaka, Atsuko; Nakamura, Teppei; Hirota, Tatsuhiko; Matsushita, Akiko; Asakura, Masanori; Ohki, Kohji; Kitakaze, Masafumi

    2014-08-01

    Both endothelial dysfunction and arterial stiffness are surrogate markers of atherosclerosis and thus cardiovascular (CV) events. The milk-derived peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) inhibit angiotensin-converting enzyme, dilate blood vessels ex vivo and stimulate nitric oxide (NO) production in cells. In this study, we investigated the effects of either VPP or IPP on arterial function and on target organ damage in vivo. Male Wistar rats were treated with N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME, 1 g l(-1)), L-NAME+VPP (0.3 g l(-1)) or L-NAME+IPP (0.3 g l(-1)) in their drinking water for 8 weeks. Plasma nitrite and nitrate (NOx) levels were significantly increased in normal Wistar rats after supplementation with either VPP or IPP but not in rats that were chronically treated with L-NAME. Acetylcholine-induced vasorelaxation in the thoracic aorta ring was impaired by L-NAME, whereas vasorelaxation was significantly greater in mice treated with L-NAME+VPP for 1 or 4 weeks or L-NAME+IPP for 4 weeks than in mice treated with L-NAME alone. Four weeks of treatment with either VPP or IPP attenuated the increase in pulse wave velocity (PWV) that was induced by L-NAME. Cardiac and renal damage were observed after 8 weeks of treatment with L-NAME, and either VPP or IPP attenuated this damage. These results show that VPP or IPP attenuates arterial dysfunction and suggest that milk-derived peptides might prevent CV damage.

  18. Optimization of antibacterial peptides by genetic algorithms and cheminformatics

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Jenssen, Håvard; Cheung, Warren A.

    2011-01-01

    Pathogens resistant to available drug therapies are a pressing global health problem. Short, cationic peptides represent a novel class of agents that have lower rates of drug resistance than derivatives of current antibiotics. Previously, we created a software system utilizing artificial neural...... 47 of the top rated 50 peptides chosen from an in silico library of nearly 100 000 sequences. Here, we report a method of generating candidate peptide sequences using the heuristic evolutionary programming method of genetic algorithms (GA), which provided a large (19-fold) improvement...

  19. The response of electrostatic probes via the λ-function

    DEFF Research Database (Denmark)

    Rerup, T.O.; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    The response of an electrostatic probe is examined with reference to a planar spacer. The study involves the numerical calculation of the probe λ-function, from which response-related characteristic parameters can be derived. These parameters enable the probe detection sensitivity and spatial...

  20. Weak glycolipid binding of a microdomain-tracer peptide correlates with aggregation and slow diffusion on cell membranes.

    Directory of Open Access Journals (Sweden)

    Tim Lauterbach

    Full Text Available Organized assembly or aggregation of sphingolipid-binding ligands, such as certain toxins and pathogens, has been suggested to increase binding affinity of the ligand to the cell membrane and cause membrane reorganization or distortion. Here we show that the diffusion behavior of the fluorescently tagged sphingolipid-interacting peptide probe SBD (Sphingolipid Binding Domain is altered by modifications in the construction of the peptide sequence that both result in a reduction in binding to ganglioside-containing supported lipid membranes, and at the same time increase aggregation on the cell plasma membrane, but that do not change relative amounts of secondary structural features. We tested the effects of modifying the overall charge and construction of the SBD probe on its binding and diffusion behavior, by Surface Plasmon Resonance (SPR; Biacore analysis on lipid surfaces, and by Fluorescence Correlation Spectroscopy (FCS on live cells, respectively. SBD binds preferentially to membranes containing the highly sialylated gangliosides GT1b and GD1a. However, simple charge interactions of the peptide with the negative ganglioside do not appear to be a critical determinant of binding. Rather, an aggregation-suppressing amino acid composition and linker between the fluorophore and the peptide are required for optimum binding of the SBD to ganglioside-containing supported lipid bilayer surfaces, as well as for interaction with the membrane. Interestingly, the strength of interactions with ganglioside-containing artificial membranes is mirrored in the diffusion behavior by FCS on cell membranes, with stronger binders displaying similar characteristic diffusion profiles. Our findings indicate that for aggregation-prone peptides, aggregation occurs upon contact with the cell membrane, and rather than giving a stronger interaction with the membrane, aggregation is accompanied by weaker binding and complex diffusion profiles indicative of heterogeneous

  1. The Neurofilament-Derived Peptide NFL-TBS.40-63 Targets Neural Stem Cells and Affects Their Properties.

    Science.gov (United States)

    Lépinoux-Chambaud, Claire; Barreau, Kristell; Eyer, Joël

    2016-07-01

    Targeting neural stem cells (NSCs) in the adult brain represents a promising approach for developing new regenerative strategies, because these cells can proliferate, self-renew, and differentiate into new neurons, astrocytes, and oligodendrocytes. Previous work showed that the NFL-TBS.40-63 peptide, corresponding to the sequence of a tubulin-binding site on neurofilaments, can target glioblastoma cells, where it disrupts their microtubules and inhibits their proliferation. We show that this peptide targets NSCs in vitro and in vivo when injected into the cerebrospinal fluid. Although neurosphere formation was not altered by the peptide, the NSC self-renewal capacity and proliferation were reduced and were associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors. In the present study, the NFL-TBS.40-63 peptide targeted neural stem cells in vitro when isolated from the subventricular zone and in vivo when injected into the cerebrospinal fluid present in the lateral ventricle. The in vitro formation of neurospheres was not altered by the peptide; however, at a high concentration of the peptide, the neural stem cell (NSC) self-renewal capacity and proliferation were reduced and associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors. ©AlphaMed Press.

  2. Antioxidant properties of a radical-scavenging peptide purified from enzymatically prepared fish skin gelatin hydrolysate.

    Science.gov (United States)

    Mendis, Eresha; Rajapakse, Niranjan; Kim, Se-Kwon

    2005-02-09

    Hoki (Johnius belengerii) skin gelatin was hydrolyzed with three commercial enzymes to identify radical-scavenging potencies of derived peptides. Peptides derived from tryptic hydrolysate exhibited the highest scavenging activities on superoxide, carbon-centered 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals assessed by ESR spectroscopy. Following consecutive chromatographic separations of tryptic hydroolysate, the peptide sequence His-Gly-Pro-Leu-Gly-Pro-Leu (797 Da) acted as a strong radical scavenger under studied conditions. Further, this peptide could act as an antioxidant against linoleic acid peroxidation and the activity was closer to the highly active synthetic antioxidant butylated hydroxytoluene (BHT). In addition, antioxidative enzyme levels in cultured human hepatoma cells were increased in the presence of this peptide and it was presumed to be the peptide involved in maintaining the redox balance in the cell environment. Present data indicate that free-radical-scavenging activities of hoki skin gelatin peptides substantially contribute to their antioxidant properties measured in different oxidative systems.

  3. Peptides in headlock – a novel high-affinity and versatile peptide-binding nanobody for proteomics and microscopy

    Science.gov (United States)

    Braun, Michael B.; Traenkle, Bjoern; Koch, Philipp A.; Emele, Felix; Weiss, Frederik; Poetz, Oliver; Stehle, Thilo; Rothbauer, Ulrich

    2016-01-01

    Nanobodies are highly valuable tools for numerous bioanalytical and biotechnical applications. Here, we report the characterization of a nanobody that binds a short peptide epitope with extraordinary affinity. Structural analysis reveals an unusual binding mode where the extended peptide becomes part of a β-sheet structure in the nanobody. This interaction relies on sequence-independent backbone interactions augmented by a small number of specificity-determining side chain contacts. Once bound, the peptide is fastened by two nanobody side chains that clamp it in a headlock fashion. Exploiting this unusual binding mode, we generated a novel nanobody-derived capture and detection system. Matrix-coupled nanobody enables the fast and efficient isolation of epitope-tagged proteins from prokaryotic and eukaryotic expression systems. Additionally, the fluorescently labeled nanobody visualizes subcellular structures in different cellular compartments. The high-affinity-binding and modifiable peptide tag of this system renders it a versatile and robust tool to combine biochemical analysis with microscopic studies. PMID:26791954

  4. Design and Engineering Strategies for Synthetic Antimicrobial Peptides

    Science.gov (United States)

    Tossi, Alessandro

    Thousands of antimicrobial peptides (AMPs) of prokaryotic, fungal, plant, or animal origin have been identified, and their potential as lead compounds for the design of novel therapeutic agents in the treatment of infection, for stimulating the immune system, or in countering septic shock has been widely recognized. Added to this is their possible use in prophylaxis of infectious diseases for animal or plant protection, for disinfection of surgical instruments or industrial surfaces, and for food preservation among other commercially important applications. Since the early eighties, AMPs have been subject to a vast number of studies aimed at understanding what determines their potency and spectrum of activities against bacterial or fungal pathogens, and at maximizing these while limiting cytotoxic activities toward host cells. Much research has also been directed toward understanding specific mechanisms of action underlying the antimicrobial activity and selectivity, to be able to redesign the peptides for optimal performance. A central theme in the mode of action of many AMPs is their dynamic interaction with biological membranes, which involves various properties of these peptides such as, among others, surface hydrophobicity and polarity, charge, structure, and induced conformational variations. These features are often intimately interconnected so that engineering peptides to independently adjust any one property in particular is not an easy task. However, solid-phase peptide synthesis allows the use of a large repertoire of nonproteinogenic amino acids that can be used in the rational design of peptides to finely tune structural and physicochemical properties and precisely probe structure-function relationships.

  5. Peptide specific expansion of CD8(+) T cells by recombinant plate bound MHC/peptide complexes

    DEFF Research Database (Denmark)

    Schmidt, Esben G W; Buus, Soren; Thorn, Mette

    2009-01-01

    to in vitro T cell stimulation was investigated. By use of an antigenic peptide derived from the cytomegalovirus (CMVp) we tested the stimulatory efficacy of recombinant plate bound MHC molecules (PB-MHC), being immobilized in culture plates. A single stimulation of non-adherent peripheral blood mononuclear...

  6. Surface force measurements and simulations of mussel-derived peptide adhesives on wet organic surfaces.

    Science.gov (United States)

    Levine, Zachary A; Rapp, Michael V; Wei, Wei; Mullen, Ryan Gotchy; Wu, Chun; Zerze, Gül H; Mittal, Jeetain; Waite, J Herbert; Israelachvili, Jacob N; Shea, Joan-Emma

    2016-04-19

    Translating sticky biological molecules-such as mussel foot proteins (MFPs)-into synthetic, cost-effective underwater adhesives with adjustable nano- and macroscale characteristics requires an intimate understanding of the glue's molecular interactions. To help facilitate the next generation of aqueous adhesives, we performed a combination of surface forces apparatus (SFA) measurements and replica-exchange molecular dynamics (REMD) simulations on a synthetic, easy to prepare, Dopa-containing peptide (MFP-3s peptide), which adheres to organic surfaces just as effectively as its wild-type protein analog. Experiments and simulations both show significant differences in peptide adsorption on CH3-terminated (hydrophobic) and OH-terminated (hydrophilic) self-assembled monolayers (SAMs), where adsorption is strongest on hydrophobic SAMs because of orientationally specific interactions with Dopa. Additional umbrella-sampling simulations yield free-energy profiles that quantitatively agree with SFA measurements and are used to extract the adhesive properties of individual amino acids within the context of MFP-3s peptide adhesion, revealing a delicate balance between van der Waals, hydrophobic, and electrostatic forces.

  7. Characterization of Protein and Peptide Binding to Nanogels Formed by Differently Charged Chitosan Derivatives

    Directory of Open Access Journals (Sweden)

    Anastasia Zubareva

    2013-07-01

    Full Text Available Chitosan (Chi is a natural biodegradable cationic polymer with remarkable potency as a vehicle for drug or vaccine delivery. Chi possesses multiple groups, which can be used both for Chi derivatization and for particle formation. The aim of this work was to produce stable nanosized range Chi gels (nanogels, NGs with different charge and to study the driving forces of complex formation between Chi NGs and proteins or peptides. Positively charged NGs of 150 nm in diameter were prepared from hexanoyl chitosan (HC by the ionotropic gelation method while negatively charged NGs of 190 nm were obtained from succinoyl Chi (SC by a Ca2+ coacervation approach. NGs were loaded with a panel of proteins or peptides with different weights and charges. We show that NGs preferentially formed complexes with oppositely charged molecules, especially peptides, as was demonstrated by gel-electrophoresis, confocal microscopy and HPLC. Complex formation was accompanied by a change in zeta-potential and decrease in size. We concluded that complex formation between Chi NGs and peptide/proteins is mediated mostly by electrostatic interactions.

  8. A lysosome-targetable turn-on fluorescent probe for the detection of thiols in living cells based on a 1,8-naphthalimide derivative

    Science.gov (United States)

    Liang, Beibei; Wang, Baiyan; Ma, Qiujuan; Xie, Caixia; Li, Xian; Wang, Suiping

    2018-03-01

    Biological thiols, like cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play crucial roles in biological systems and in lysosomal processes. Highly selective probes for detecting biological thiols in lysomes of living cells are rare. In this work, a lysosome-targetable turn-on fluorescent probe for the detection of thiols in living cells was designed and synthesized based on a 1,8-naphthalimide derivative. The probe has a 4-(2-aminoethyl)morpholine unit as a lysosome-targetable group and an acrylate group as the thiol recognition unit as well as a fluorescence quencher. In the absence of biothiols, the probe displayed weak fluorescence due to the photoinduced electron transfer (PET) process. Upon the addition of biothiols, the probe exhibited an enhanced fluorescence emission centered at 550 nm due to cleavage of the acrylate moiety. The probe had high selectivity toward biothiols. Moreover, the probe features fast response time, excitation in the visible region and ability of working in a wide pH range. The linear response range covers a concentration range of Cys from 1.5 × 10- 7 to 1.0 × 10- 5 mol·L- 1 and the detection limit is 6.9 × 10- 8 mol·L- 1 for Cys. The probe has been successfully applied to the confocal imaging of biothiols in lysosomes of A549 cells with low cell toxicity. Furthermore, the method was successfully applied to the determination of thiols in a complex multicomponent mixture such as human serum, which suggests our proposed method has great potential for diagnostic purposes. All of such good properties prove it can be used to monitor biothiols in lysosomes of living cells and to be a good fluorescent probe for the selective detection of thiols.

  9. 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.

  10. Folding and activity of hybrid sequence, disulfide-stabilized peptides

    Energy Technology Data Exchange (ETDEWEB)

    Pease, J.H.B.; Storrs, R.W.; Wemmer, D.E. (Univ. of California, Berkeley (USA))

    1990-08-01

    Peptides have been synthesized that have hybrid sequences, partially derived from the bee venom peptide apamin and partially from the S peptide of ribonuclease A. The hybrid peptides were demonstrated by NMR spectroscopy to fold, forming the same disulfides and basic three-dimensional structure as native apamin, containing a {beta}-turn and an {alpha}-helix. These hybrids were active in complementing S protein, reactivating nuclease activity. In addition, the hybrid peptide was effective in inducing antibodies that cross-react with the RNase, without conjugation to a carrier protein. The stability of the folded structure of this peptide suggests that it should be possible to elicit antibodies that will react not only with a specific sequence, but also with a specific secondary structure. Hybrid sequence peptides also provide opportunities to study separately nucleation and propagation steps in formation of secondary structure. The authors show that in S peptide the {alpha}-helix does not end abruptly but rather terminates gradually over four or five residues. In general, these hybrid sequence peptides, which fold predictably because of disulfide bond formation, can provide opportunities for examining structure - function relationships for many biologically active sequences.

  11. Folding and activity of hybrid sequence, disulfide-stabilized peptides

    International Nuclear Information System (INIS)

    Pease, J.H.B.; Storrs, R.W.; Wemmer, D.E.

    1990-01-01

    Peptides have been synthesized that have hybrid sequences, partially derived from the bee venom peptide apamin and partially from the S peptide of ribonuclease A. The hybrid peptides were demonstrated by NMR spectroscopy to fold, forming the same disulfides and basic three-dimensional structure as native apamin, containing a β-turn and an α-helix. These hybrids were active in complementing S protein, reactivating nuclease activity. In addition, the hybrid peptide was effective in inducing antibodies that cross-react with the RNase, without conjugation to a carrier protein. The stability of the folded structure of this peptide suggests that it should be possible to elicit antibodies that will react not only with a specific sequence, but also with a specific secondary structure. Hybrid sequence peptides also provide opportunities to study separately nucleation and propagation steps in formation of secondary structure. The authors show that in S peptide the α-helix does not end abruptly but rather terminates gradually over four or five residues. In general, these hybrid sequence peptides, which fold predictably because of disulfide bond formation, can provide opportunities for examining structure - function relationships for many biologically active sequences

  12. A Solid-State Deuterium NMR and SFG Study of the Side Chain Dynamics of Peptides Adsorbed onto Surfaces

    Science.gov (United States)

    Breen, Nicholas F.; Weidner, Tobias; Li, Kun; Castner, David G.; Drobny, Gary P.

    2011-01-01

    The artificial amphiphilic peptide LKα14 adopts a helical structure at interfaces, with opposite orientation of its leucine (L, hydrophobic) and lysine (K, hydrophilic) side chains. When adsorbed onto surfaces, different residue side chains necessarily have different proximities to the surface, depending on both their position in the helix and the composition of the surface itself. Deuterating the individual leucine residues (isopropyl-d7) permits the use of solid-state deuterium NMR as a site-specific probe of side chain dynamics. In conjunction with SFG as a probe of the peptide binding face, we demonstrate that the mobility of specific leucine side chains at the interface is quantifiable in terms of their surface proximity. PMID:19764755

  13. Probing protein surface with a solvent mimetic carbene coupled to detection by mass spectrometry.

    Science.gov (United States)

    Gómez, Gabriela E; Mundo, Mariana R; Craig, Patricio O; Delfino, José M

    2012-01-01

    Much knowledge into protein folding, ligand binding, and complex formation can be derived from the examination of the nature and size of the accessible surface area (SASA) of the polypeptide chain, a key parameter in protein science not directly measurable in an experimental fashion. To this end, an ideal chemical approach should aim at exerting solvent mimicry and achieving minimal selectivity to probe the protein surface regardless of its chemical nature. The choice of the photoreagent diazirine to fulfill these goals arises from its size comparable to water and from being a convenient source of the extremely reactive methylene carbene (:CH(2)). The ensuing methylation depends primarily on the solvent accessibility of the polypeptide chain, turning it into a valuable signal to address experimentally the measurement of SASA in proteins. The superb sensitivity and high resolution of modern mass spectrometry techniques allows us to derive a quantitative signal proportional to the extent of modification (EM) of the sample. Thus, diazirine labeling coupled to electrospray mass spectrometry (ESI-MS) detection can shed light on conformational features of the native as well as non-native states, not easily addressable by other methods. Enzymatic fragmentation of the polypeptide chain at the level of small peptides allows us to locate the covalent tag along the amino acid sequence, therefore enabling the construction of a map of solvent accessibility. Moreover, by subsequent MS/MS analysis of peptides, we demonstrate here the feasibility of attaining amino acid resolution in defining the target sites. © American Society for Mass Spectrometry, 2011

  14. De novo design and engineering of non-ribosomal peptide synthetases

    Science.gov (United States)

    Bozhüyük, Kenan A. J.; Fleischhacker, Florian; Linck, Annabell; Wesche, Frank; Tietze, Andreas; Niesert, Claus-Peter; Bode, Helge B.

    2018-03-01

    Peptides derived from non-ribosomal peptide synthetases (NRPSs) represent an important class of pharmaceutically relevant drugs. Methods to generate novel non-ribosomal peptides or to modify peptide natural products in an easy and predictable way are therefore of great interest. However, although the overall modular structure of NRPSs suggests the possibility of adjusting domain specificity and selectivity, only a few examples have been reported and these usually show a severe drop in production titre. Here we report a new strategy for the modification of NRPSs that uses defined exchange units (XUs) and not modules as functional units. XUs are fused at specific positions that connect the condensation and adenylation domains and respect the original specificity of the downstream module to enable the production of the desired peptides. We also present the use of internal condensation domains as an alternative to other peptide-chain-releasing domains for the production of cyclic peptides.

  15. Labeling, stability and biodistribution studies of {sup 99m}Tc-cyclized Tyr{sup 3}-octreotate derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Bigott-Hennkens, Heather M. [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Dannoon, Shorouk F.; Noll, Samantha M. [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Ruthengael, Varyanna C. [Research Service, Harry S Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Jurisson, Silvia S., E-mail: JurissonS@missouri.ed [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Lewis, Michael R., E-mail: LewisMic@missouri.ed [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Research Service, Harry S Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States)

    2011-05-15

    Introduction: To probe the interplay between radiotracer stability and somatostatin receptor affinity, Tyr{sup 3}-octreotate and six variations of its peptide sequence, for which the Re-cyclized products were previously reported, were radiolabeled with {sup 99m}Tc and investigated for their in vitro stability. Methods: Radiolabeling of the peptides was effected by ligand exchange from {sup 99m}Tc-glucoheptonate, and the desired products were purified by radio-RP-HPLC. The in vitro stability in phosphate buffered saline, mouse serum and cysteine solutions at physiological temperature and pH for all seven {sup 99m}Tc-cyclized peptides was determined by radio-RP-HPLC and radio-TLC. Normal CF-1 mouse biodistribution studies were performed for three of the {sup 99m}Tc-cyclized peptides. Results: Based on the fully characterized Re-cyclized peptide analogues, four {sup 99m}Tc-coordination motifs were proposed for the {sup 99m}Tc-cyclized peptides. Technetium-99m-cyclized Tyr{sup 3}-octreotate derivatives with N{sub 2}S{sub 2} metal coordination modes and large metal ring sizes were susceptible to oxidation and loss of {sup 99m}Tc in the form of {sup 99m}TcO{sub 4}{sup -}, as evidenced by their instability in the various solutions under physiological conditions (15-58% intact at 24 h). As anticipated, the addition of a third cysteine to the sequence stabilized the {sup 99m}Tc metal coordination, and peptides with NS{sub 3} coordination modes remained >85% intact out to 24 h. No significant differences were observed in the biodistribution studies performed with three peptides of varying stabilities. Conclusions: Improvements in stability were not sufficient to outweigh the low somatostatin receptor affinity for the peptides in this study. Further improvements in the peptide sequence and/or metal coordination are needed to result in a radiodiagnostic/radiotherapeutic pair for targeting the somatostatin receptor.

  16. Self-assembled peptide nanotubes as an etching material for the rapid fabrication of silicon wires

    DEFF Research Database (Denmark)

    Larsen, Martin Benjamin Barbour Spanget; Andersen, Karsten Brandt; Svendsen, Winnie Edith

    2011-01-01

    This study has evaluated self-assembled peptide nanotubes (PNTS) and nanowires (PNWS) as etching mask materials for the rapid and low-cost fabrication of silicon wires using reactive ion etching (RIE). The self-assembled peptide structures were fabricated under mild conditions and positioned on c...... characterization by SEM and I-V measurements. Additionally, the fabricated silicon structures were functionalized with fluorescent molecules via a biotin-streptavidin interaction in order to probe their potential in the development of biosensing devices....

  17. PNA-COMBO-FISH: From combinatorial probe design in silico to vitality compatible, specific labelling of gene targets in cell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Müller, Patrick; Rößler, Jens; Schwarz-Finsterle, Jutta [University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany); Schmitt, Eberhard, E-mail: eschmitt@kip.uni-heidelberg.de [University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany); University of Göttingen, Institute for Numerical and Applied Mathematics, Lotzestraße 16-18, D-37083 Göttingen (Germany); Hausmann, Michael, E-mail: hausmann@kip.uni-heidelberg.de [University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany)

    2016-07-01

    Recently, advantages concerning targeting specificity of PCR constructed oligonucleotide FISH probes in contrast to established FISH probes, e.g. BAC clones, have been demonstrated. These techniques, however, are still using labelling protocols with DNA denaturing steps applying harsh heat treatment with or without further denaturing chemical agents. COMBO-FISH (COMBinatorial Oligonucleotide FISH) allows the design of specific oligonucleotide probe combinations in silico. Thus, being independent from primer libraries or PCR laboratory conditions, the probe sequences extracted by computer sequence data base search can also be synthesized as single stranded PNA-probes (Peptide Nucleic Acid probes). Gene targets can be specifically labelled with at least about 20 PNA-probes obtaining visibly background free specimens. By using appropriately designed triplex forming oligonucleotides, the denaturing procedures can completely be omitted. These results reveal a significant step towards oligonucleotide-FISH maintaining the 3D-nanostructure and even the viability of the cell target. The method is demonstrated with the detection of Her2/neu and GRB7 genes, which are indicators in breast cancer diagnosis and therapy. - Highlights: • Denaturation free protocols preserve 3D architecture of chromosomes and nuclei. • Labelling sets are determined in silico for duplex and triplex binding. • Probes are produced chemically with freely chosen backbones and base variants. • Peptide nucleic acid backbones reduce hindering charge interactions. • Intercalating side chains stabilize binding of short oligonucleotides.

  18. PNA-COMBO-FISH: From combinatorial probe design in silico to vitality compatible, specific labelling of gene targets in cell nuclei

    International Nuclear Information System (INIS)

    Müller, Patrick; Rößler, Jens; Schwarz-Finsterle, Jutta; Schmitt, Eberhard; Hausmann, Michael

    2016-01-01

    Recently, advantages concerning targeting specificity of PCR constructed oligonucleotide FISH probes in contrast to established FISH probes, e.g. BAC clones, have been demonstrated. These techniques, however, are still using labelling protocols with DNA denaturing steps applying harsh heat treatment with or without further denaturing chemical agents. COMBO-FISH (COMBinatorial Oligonucleotide FISH) allows the design of specific oligonucleotide probe combinations in silico. Thus, being independent from primer libraries or PCR laboratory conditions, the probe sequences extracted by computer sequence data base search can also be synthesized as single stranded PNA-probes (Peptide Nucleic Acid probes). Gene targets can be specifically labelled with at least about 20 PNA-probes obtaining visibly background free specimens. By using appropriately designed triplex forming oligonucleotides, the denaturing procedures can completely be omitted. These results reveal a significant step towards oligonucleotide-FISH maintaining the 3D-nanostructure and even the viability of the cell target. The method is demonstrated with the detection of Her2/neu and GRB7 genes, which are indicators in breast cancer diagnosis and therapy. - Highlights: • Denaturation free protocols preserve 3D architecture of chromosomes and nuclei. • Labelling sets are determined in silico for duplex and triplex binding. • Probes are produced chemically with freely chosen backbones and base variants. • Peptide nucleic acid backbones reduce hindering charge interactions. • Intercalating side chains stabilize binding of short oligonucleotides.

  19. Impact of the NCAM derived mimetic peptide plannexin on the acute cellular consequences of a status epilepticus

    DEFF Research Database (Denmark)

    Zellinger, Christina; Hadamitzky, Martin; Bock, Elisabeth

    2011-01-01

    Plannexin represents a NCAM-derived peptide mimicking trans-homophilic NCAM interaction, which proved to exert neuroprotective effects in vitro. The effect of plannexin was evaluated in a rat status epilepticus model. As expected, prolonged seizure activity resulted in a pronounced cell loss...... in hippocampal subregions. The comparison between the vehicle- and plannexin-treated animals with status epilepticus did not reveal neuroprotective effects of plannexin on mature neurons. However, treatment with plannexin partially prevented the reduction in the number of doublecortin-labeled neuronal progenitor...... cells, which was evident 48h following status epilepticus. In conclusion, the data might give first evidence that plannexin can protect immature neurons in vivo. Future studies are necessary to evaluate whether disease-modifying or preventive effects are observed in models of epileptogenesis....

  20. Antimicrobial activity of GN peptides and their mode of action

    DEFF Research Database (Denmark)

    Mojsoska, Biljana; Nielsen, Hanne Mørck; Jenssen, Håvard

    2016-01-01

    peptides due to their characteristics as naturally derived compounds with antimicrobial activity. In this study, we aimed at characterizing the mechanism of action of a small set of in silico optimized peptides. Following determination of peptide activity against E. coli, S. aureus, and P. aeruginosa......Increasing prevalence of bacteria that carries resistance towards conventional antibiotics has prompted the investigation into new compounds for bacterial intervention to ensure efficient infection control in the future. One group of potential lead structures for antibiotics is antimicrobial...

  1. Peptide-Conjugated Quantum Dots Act as the Target Marker for Human Pancreatic Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Shuang-ling Li

    2016-03-01

    Full Text Available Background/Aims: In the present study, we describe a novel and straightforward approach to produce a cyclic- arginine-glycine-aspartic (RGD-peptide-conjugated quantum dot (QD probe as an ideal target tumor biomarker. Due to its specific structure, the probe can be used for targeted imaging of pancreatic carcinoma cells. Methods: Pancreatic carcinoma cells were routinely cultured and marked with QD-RGD probe. The QD-RGD probe on the fluorescence-labeled cancer cell was observed by fluorescence microscopy and laser confocal microscopy. Cancer cell viability was detected by MTT assay after culturing with QD-RGD probe. Results: Fluorescence microscopy and laser confocal microscopy displayed that 10nmol/L QD-RGD probe was able to effectively mark pancreatic carcinoma cells. In comparison with organic dyes and fluorescent proteins, the quantum dot-RGD probe had unique optical and electronic properties. Conclusion: QD-RGD probe has a low cytotoxicity with an excellent optical property and biocompatibility. These findings support further evaluation of QD-RGD probes for the early detection of pancreatic cancer.

  2. Molecular evolution of a peptide GPCR ligand driven by artificial neural networks.

    Directory of Open Access Journals (Sweden)

    Sebastian Bandholtz

    Full Text Available Peptide ligands of G protein-coupled receptors constitute valuable natural lead structures for the development of highly selective drugs and high-affinity tools to probe ligand-receptor interaction. Currently, pharmacological and metabolic modification of natural peptides involves either an iterative trial-and-error process based on structure-activity relationships or screening of peptide libraries that contain many structural variants of the native molecule. Here, we present a novel neural network architecture for the improvement of metabolic stability without loss of bioactivity. In this approach the peptide sequence determines the topology of the neural network and each cell corresponds one-to-one to a single amino acid of the peptide chain. Using a training set, the learning algorithm calculated weights for each cell. The resulting network calculated the fitness function in a genetic algorithm to explore the virtual space of all possible peptides. The network training was based on gradient descent techniques which rely on the efficient calculation of the gradient by back-propagation. After three consecutive cycles of sequence design by the neural network, peptide synthesis and bioassay this new approach yielded a ligand with 70fold higher metabolic stability compared to the wild type peptide without loss of the subnanomolar activity in the biological assay. Combining specialized neural networks with an exploration of the combinatorial amino acid sequence space by genetic algorithms represents a novel rational strategy for peptide design and optimization.

  3. Antioxidant activity of a novel synthetic hexa-peptide derived from an enzymatic hydrolysate of duck skin by-products.

    Science.gov (United States)

    Lee, Seung-Jae; Cheong, Sun Hee; Kim, Yon-Suk; Hwang, Jin-Woo; Kwon, Hyuck-Ju; Kang, Seo-Hee; Moon, Sang-Ho; Jeon, Byong-Tae; Park, Pyo-Jam

    2013-12-01

    A peptide was synthesized on the basis of our previous study from solid phase peptide synthesis using ASP48S (Peptron Inc.) and identified by the reverse phase high-performance liquid chromatography (HPLC) using a Vydac Everest C18 column. The molecular mass of the peptide found to be 693.90 Da, and the amino acid sequences of the peptide was Trp-Tyr-Pro-Ala-Ala-Pro. The purpose of this study was to evaluate antioxidant effects of the peptide by electron spin resonance (ESR) spectrometer, and on t-BHP-induced liver cells damage in Chang cells. The antioxidative activity of the peptide was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, alkyl and superoxide radical scavenging activity using an ESR spectrometer. The half maximal inhibitory concentration (IC50) value of the peptide for hydroxyl, DPPH, alkyl, and superoxide radical scavenging activity were 45.2, 18.5, 31.5, and 33.4 μM, respectively. In addition, the peptide inhibited productions of cell death against t-BHP-induced liver cell damage in Chang cells. It was presumed to be peptide involved in regulating the apoptosis-related gene expression in the cell environment. The present results indicate that the peptide substantially contributes to antioxidative properties in liver cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Cytosolic antibody delivery by lipid-sensitive endosomolytic peptide

    Science.gov (United States)

    Akishiba, Misao; Takeuchi, Toshihide; Kawaguchi, Yoshimasa; Sakamoto, Kentarou; Yu, Hao-Hsin; Nakase, Ikuhiko; Takatani-Nakase, Tomoka; Madani, Fatemeh; Gräslund, Astrid; Futaki, Shiroh

    2017-08-01

    One of the major obstacles in intracellular targeting using antibodies is their limited release from endosomes into the cytosol. Here we report an approach to deliver proteins, which include antibodies, into cells by using endosomolytic peptides derived from the cationic and membrane-lytic spider venom peptide M-lycotoxin. The delivery peptides were developed by introducing one or two glutamic acid residues into the hydrophobic face. One peptide with the substitution of leucine by glutamic acid (L17E) was shown to enable a marked cytosolic liberation of antibodies (immunoglobulins G (IgGs)) from endosomes. The predominant membrane-perturbation mechanism of this peptide is the preferential disruption of negatively charged membranes (endosomal membranes) over neutral membranes (plasma membranes), and the endosomolytic peptide promotes the uptake by inducing macropinocytosis. The fidelity of this approach was confirmed through the intracellular delivery of a ribosome-inactivation protein (saporin), Cre recombinase and IgG delivery, which resulted in a specific labelling of the cytosolic proteins and subsequent suppression of the glucocorticoid receptor-mediated transcription. We also demonstrate the L17E-mediated cytosolic delivery of exosome-encapsulated proteins.

  5. Peptides of the constant region of antibodies display fungicidal activity.

    Directory of Open Access Journals (Sweden)

    Luciano Polonelli

    Full Text Available Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA of antibodies (Fc-peptides exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents.

  6. Peptides of the Constant Region of Antibodies Display Fungicidal Activity

    Science.gov (United States)

    Polonelli, Luciano; Ciociola, Tecla; Magliani, Walter; Zanello, Pier Paolo; D'Adda, Tiziana; Galati, Serena; De Bernardis, Flavia; Arancia, Silvia; Gabrielli, Elena; Pericolini, Eva; Vecchiarelli, Anna; Arruda, Denise C.; Pinto, Marcia R.; Travassos, Luiz R.; Pertinhez, Thelma A.; Spisni, Alberto; Conti, Stefania

    2012-01-01

    Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents. PMID:22470523

  7. Antitumor activity of novel chimeric peptides derived from cyclinD/CDK4 and the protein transduction domain 4.

    Science.gov (United States)

    Wang, Haili; Chen, Xi; Chen, Yanping; Sun, Lei; Li, Guodong; Zhai, Mingxia; Zhai, Wenjie; Kang, Qiaozhen; Gao, Yanfeng; Qi, Yuanming

    2013-02-01

    CyclinD1/CDK4 and cyclinD3/CDK4 complexes are key regulators of the cell progression and therefore constitute promising targets for the design of anticancer agents. In the present study, the key peptide motifs were selected from these two complexes. Chimeric peptides with these peptides conjugated to the protein transduction domain 4 (PTD4) were designed and synthesized. The chimeric peptides, PTD4-D1, PTD4-D3, PTD4-K4 exhibited significant anti-proliferation effects on cancer cell lines. These peptides could compete with the cyclinD/CDK4 complex and induce the G1/S phase arrest and apoptosis of cancer cells. In the tumor challenge experiment, these peptides showed potent antitumor effects with no significant side effects. Our results suggested that these peptides could be served as novel leading compounds with potent antitumor activity.

  8. Silver nanoparticles as matrix for laser desorption/ionization mass spectrometry of peptides

    International Nuclear Information System (INIS)

    Hua Lin; Chen Jianrong; Ge Liya; Tan, Swee Ngin

    2007-01-01

    Silver nanoparticle synthesized from chemical reduction has been successfully utilized as a matrix in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of peptides. Acting as a substrate to adsorb analytes, as well as a transmission medium for UV laser, silver nanoparticle was found to assist in the desorption/ionization of peptides with little or no induced fragmentation. The size of the nanoparticle was typically in the range of 160 ± 20 nm. One of the key advantages of silver nanoparticle for peptides analysis is its simple step for on-probe sample preparation. In addition, it also minimizes the interferences of sodium dodecyl sulfate (SDS) surfactant background signal, resulting in cleaner mass spectra and more sensitive signal, when compared to α-cyano-4-hydroxycinnamic acid (CCA) matrix

  9. Synthesis and evaluation of [{sup 14}C]-Labelled and fluorescent-Tagged paclitaxel derivatives as new biological probes

    Energy Technology Data Exchange (ETDEWEB)

    Rao, C.S.; Chu, J.-J.; Lai, Y.-K. [Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan (China); Liu, R.-S. [Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan (China)

    1998-11-01

    Our present report deals with the preparation of hitherto unreported 7-([carbonyl-{sup 14}C]-acetyl)paclitaxel 4 and two new bioactive 7-substituted fluorescent taxoids (FITC 9 and rhodamine 11), as well as evaluation towards their applications as biological probes. The results in this report demonstrate that (a) the new paclitaxel derivatives 4, 9, 11 could be prepared with good yields starting from paclitaxel; (b) the [{sup 14}C]acetylation step was found to be better by using [{sup 14}C]acetic anhydride rather than [{sup 14}C]sodium acetate; (c) the radiochemical purity of 4 was 96% and its specific activity was 48 mCi/mmol; (d) the cytotoxicity of 4 was close to that of paclitaxel whereas 9, 11 were far less active than paclitaxel, but these cytotoxic levels were good enough for their biological applications; (e) the drug-quantitation by flow cytometric analysis using 9 and 11 was proved to be equally efficient with respect to the radioactivity-based determination employing 4; (f) the intracellular fluorescence mapping by 9 and 11 was found to be effective and the microtubule network pattern was visible in both the cases; (g) the overall fluorescence imaging efficiency was better with 11 while the intensity of fluorescence was higher with 9; (h) staining of nucleolus was observed in fluorescence studies of both 9 and 11. Based on these results, the newly prepared paclitaxel derivatives can be considered as efficient biological probes and should find further use in relevant applications. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Science.gov (United States)

    Amoutzias, Grigoris D.; Chaliotis, Anargyros; Mossialos, Dimitris

    2016-01-01

    Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs) and polyketides (PKs) are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes) and type-I polyketide synthases (PKSes-I), respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS) technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds. PMID:27092515

  11. Discovery Strategies of Bioactive Compounds Synthesized by Nonribosomal Peptide Synthetases and Type-I Polyketide Synthases Derived from Marine Microbiomes

    Directory of Open Access Journals (Sweden)

    Grigoris D. Amoutzias

    2016-04-01

    Full Text Available Considering that 70% of our planet’s surface is covered by oceans, it is likely that undiscovered biodiversity is still enormous. A large portion of marine biodiversity consists of microbiomes. They are very attractive targets of bioprospecting because they are able to produce a vast repertoire of secondary metabolites in order to adapt in diverse environments. In many cases secondary metabolites of pharmaceutical and biotechnological interest such as nonribosomal peptides (NRPs and polyketides (PKs are synthesized by multimodular enzymes named nonribosomal peptide synthetases (NRPSes and type-I polyketide synthases (PKSes-I, respectively. Novel findings regarding the mechanisms underlying NRPS and PKS evolution demonstrate how microorganisms could leverage their metabolic potential. Moreover, these findings could facilitate synthetic biology approaches leading to novel bioactive compounds. Ongoing advances in bioinformatics and next-generation sequencing (NGS technologies are driving the discovery of NRPs and PKs derived from marine microbiomes mainly through two strategies: genome-mining and metagenomics. Microbial genomes are now sequenced at an unprecedented rate and this vast quantity of biological information can be analyzed through genome mining in order to identify gene clusters encoding NRPSes and PKSes of interest. On the other hand, metagenomics is a fast-growing research field which directly studies microbial genomes and their products present in marine environments using culture-independent approaches. The aim of this review is to examine recent developments regarding discovery strategies of bioactive compounds synthesized by NRPS and type-I PKS derived from marine microbiomes and to highlight the vast diversity of NRPSes and PKSes present in marine environments by giving examples of recently discovered bioactive compounds.

  12. Receptors for GRP/bombesin-like peptides in the rat forebrain

    International Nuclear Information System (INIS)

    Wolf, S.S.; Moody, T.W.

    1985-01-01

    Binding sites in the rat forebrain were characterized using ( 125 I-Tyr4)bombesin as a receptor probe. Pharmacology experiments indicate that gastrin releasing peptide (GRP) and the GRP fragments GRP as well as Ac-GRP inhibited radiolabeled (Tyr4)bombesin binding with high affinity. Biochemistry experiments indicated that heat, N-ethyl maleimide or trypsin greatly reduced radiolabeled (Tyr4)bombesin binding. Also, autoradiographic studies indicated that highest grain densities were present in the stria terminalis, periventricular and suprachiasmatic nucleus of the hypothalamus, dorsomedial and rhomboid thalamus, dentate gyrus, hippocampus and medial amygdaloid nucleus. The data suggest that CNS protein receptors, which are discretely distributed in the rat forebrain, may mediate the action of endogenous GRP/bombesin-like peptides

  13. Hotspot autoimmune T cell receptor binding underlies pathogen and insulin peptide cross-reactivity

    Science.gov (United States)

    Cole, David K.; Bulek, Anna M.; Dolton, Garry; Schauenberg, Andrea J.; Szomolay, Barbara; Trimby, Andrew; Jothikumar, Prithiviraj; Fuller, Anna; Skowera, Ania; Rossjohn, Jamie; Zhu, Cheng; Miles, John J.; Wooldridge, Linda; Rizkallah, Pierre J.; Sewell, Andrew K.

    2016-01-01

    The cross-reactivity of T cells with pathogen- and self-derived peptides has been implicated as a pathway involved in the development of autoimmunity. However, the mechanisms that allow the clonal T cell antigen receptor (TCR) to functionally engage multiple peptide–major histocompatibility complexes (pMHC) are unclear. Here, we studied multiligand discrimination by a human, preproinsulin reactive, MHC class-I–restricted CD8+ T cell clone (1E6) that can recognize over 1 million different peptides. We generated high-resolution structures of the 1E6 TCR bound to 7 altered peptide ligands, including a pathogen-derived peptide that was an order of magnitude more potent than the natural self-peptide. Evaluation of these structures demonstrated that binding was stabilized through a conserved lock-and-key–like minimal binding footprint that enables 1E6 TCR to tolerate vast numbers of substitutions outside of this so-called hotspot. Highly potent antigens of the 1E6 TCR engaged with a strong antipathogen-like binding affinity; this engagement was governed though an energetic switch from an enthalpically to entropically driven interaction compared with the natural autoimmune ligand. Together, these data highlight how T cell cross-reactivity with pathogen-derived antigens might break self-tolerance to induce autoimmune disease. PMID:27183389

  14. Chicken cathelicidin-2-derived peptides with enhanced immunomodulatory and antibacterial activities against biological warfare agents

    NARCIS (Netherlands)

    Molhoek, E.M.; Dijk, A. van; Veldhuizen, E.J.A.; Dijk-Knijnenburg, H.; Mars-Groenendijk, R.H.; Boele, L.C.L.; Kaman-van Zanten, W.E.; Haagsman, H.P.; Bikker, F.J.

    2010-01-01

    Host defence peptides (HDPs) are considered to be excellent candidates for the development of novel therapeutic agents. Recently, it was demonstrated that the peptide C1-15, an N-terminal segment of chicken HDP cathelicidin-2, exhibits potent antibacterial activity while lacking cytotoxicity towards

  15. Peptide insertion, positioning, and stabilization in a membrane: insight from an all-atom molecular dynamics simulation.

    Science.gov (United States)

    Babakhani, Arneh; Gorfe, Alemayehu A; Gullingsrud, Justin; Kim, Judy E; Andrew McCammon, J

    Peptide insertion, positioning, and stabilization in a model membrane are probed via an all-atom molecular dynamics (MD) simulation. One peptide (WL5) is simulated in each leaflet of a solvated dimyristoylglycero-3-phosphate (DMPC) membrane. Within the first 5 ns, the peptides spontaneously insert into the membrane and then stabilize during the remaining 70 ns of simulation time. In both leaflets, the peptides localize to the membrane interface, and this localization is attributed to the formation of peptide-lipid hydrogen bonds. We show that the single tryptophan residue in each peptide contributes significantly to these hydrogen bonds; specifically, the nitrogen heteroatom of the indole ring plays a critical role. The tilt angles of the indole rings relative to the membrane normal in the upper and lower leaflets are approximately 26 degrees and 54 degrees , respectively. The tilt angles of the entire peptide chain are 62 degrees and 74 degrees . The membrane induces conformations of the peptide that are characteristic of beta-sheets, and the peptide enhances the lipid ordering in the membrane. Finally, the diffusion rate of the peptides in the membrane plane is calculated (based on experimental peptide concentrations) to be approximately 6 A(2)/ns, thus suggesting a 500 ns time scale for intermolecular interactions.

  16. Effects of lactoferrin derived peptides on simulants of biological warfare agents

    NARCIS (Netherlands)

    Sijbrandij, T.; Ligtenberg, Antoon J.; Nazmi, K.; Veerman, Enno C. I.; Bolscher, Jan G. M.; Bikker, Floris J.

    2017-01-01

    Lactoferrin (LF) is an important immune protein in neutrophils and secretory fluids of mammals. Bovine LF (bLF) harbours two antimicrobial stretches, lactoferricin and lactoferampin, situated in close proximity in the N1 domain. To mimic these antimicrobial domain parts a chimeric peptide

  17. Photoaffinity cross-linking of a radioiodinated probe, 125I-A55453, into alpha 1-adrenergic receptors

    International Nuclear Information System (INIS)

    Dickinson, K.E.; Leeb-Lundberg, L.M.; Heald, S.L.; Wikberg, J.E.; DeBernardis, J.F.; Caron, M.G.; Lefkowitz, R.J.

    1984-01-01

    We have synthesized and characterized a high-affinity alpha 1-adrenergic receptor probe, 4-amino-6,7-dimethoxy-2[4'- [5''(3'''- 125 I-iodo-4'''-aminophenyl)pentanoyl]-1'-piperazinyl] quinazoline ( 125 I-A55453). This ligand binds reversibly to rat hepatic plasma membranes with high affinity (KD . 77 +/- 6 pM), and it labels the same number of specific prazosin-competable sites as the alpha 1-adrenergic receptor-selective radioligand [ 125 I] iodo-2-[beta-(4-hydroxyphenyl)-ethylaminomethyl]tetralone. Specific binding is stereoselective and competed for by alpha-adrenergic agents with an alpha 1-adrenergic receptor specificity. 125 I-A55453 can be covalently photoincorporated into peptides of rat hepatic and splenic membranes using the bifunctional photoactive cross-linker, N-succinimidyl-6- (4'-azido-2'-nitrophenylamino)hexanoate. Following photolysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of labeled hepatic membranes reveals a major specifically labeled peptide of Mr . 82,000 (+/- 1,000) with minor peptides at Mr . 50,000 (+/- 500), and 40,000 (+/- 300). Covalent incorporation of 125 I-A55453 into the Mr . 82,000 peptide is inhibited by adrenergic drugs with an alpha 1-adrenergic receptor specificity. Labeled splenic membranes demonstrate a broad band of photoincorporated radioactivity centered at Mr . 82,000, and covalent incorporation into this peptide is also attenuated with an alpha 1-adrenergic receptor specificity. This new high-affinity radioiodinated probe has features which should make it useful for the molecular characterization of alpha 1-adrenergic receptors in tissues

  18. 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

  19. Technetium-99m somatostatin analogues: effect of labelling methods and peptide sequence

    International Nuclear Information System (INIS)

    Decristoforo, C.; Mather, S.J.

    1999-01-01

    In this paper the preclinical evaluation of the somatostatin analogue RC160 labelled with technetium-99m using bifunctional chelators (BFCs) based on the hydrazinonicotinamide (HYNIC) and N 3 S system is described and a comparison made with [Tyr 3 ]-octreotide (TOC). Conjugates of both peptides with HYNIC, and of RC160 with benzoyl-MAG 3 and an N 3 S-adipate derivative were prepared and radiolabelling performed at high specific activities using tricine, tricine/nicotinic acid and ethylenediamine-N,N'-diacetic adic (EDDA) as co-ligands for HYNIC conjugates. All conjugates and 99m Tc-labelled peptides showed preserved binding affinity for the somatostatin receptor (IC50, Kd 99m Tc-RC160 derivatives compared with 99m Tc-EDDA/HYNIC-[Tyr 3 ]-octreotide (0.2%-3.5%ID/g vs 9.7%ID/g) and correlated well with the reduced internalisation rate for RC160 derivatives. Our results show that the selection of the labelling approach as well as the right choice of the peptide structure are crucial for labelling peptides with 99m Tc to achieve complexes with favourable biodistribution. Despite the relatively low tumour uptake compared with 99m Tc-EDDA/HYNIC-[Tyr 3 ]-octreotide, 99m Tc-RC160 could play a role in imaging tumours that do not bind octreotide derivatives. (orig.)

  20. Structural organization and spectroscopy of peptide-actinide(IV) complexes

    International Nuclear Information System (INIS)

    Dahou, S.

    2010-01-01

    The contamination of living organisms by actinide elements is at the origin of both radiological and chemical toxicity that may lead to severe dysfunction. Most of the data available on the actinide interaction with biological systems are macroscopic physiological measurements and are lacking a molecular description of the systems. Because of the intricacy of these systems, classical biochemical methods are difficult to implement. Our strategy consisted in designing simplified biomimetic peptides, and describing the corresponding intramolecular interactions with actinides. A carboxylic pentapeptide of the form DDPDD has been at the starting point of this work in order to further assess the influence of the peptide sequence on the topology of the complexes.To do so, various linear (Asp/Ala permutations, peptoids) and cyclic analogues have been synthesized. Furthermore, in order to include the hydroxamic function (with a high affinity for Fe(III)) in the peptide, both desferrioxamine and acetohydroxamic acid have been investigated. However because of difficulties in synthesis, we have not been able to test these peptides. Three actinide cations have been considered at oxidation state +IV (Th, Np, Pu) and compared to Fe(III), often considered as a biological surrogate of Pu(IV). The spatial arrangement of the peptide around the cation has been probed by spectrophotometry and X-ray Absorption Spectroscopy. The spectroscopic data and EXAFS data adjustment lead us to rationalize the topology of the complexes as a function of the peptide sequence: mix hydroxy polynuclear species for linear and cyclic peptides, mononuclear for the desferrioxamine complexes. Furthermore, significant differences have appeared between Fe(III) and actinide(IV), related to differences of reactivity in aqueous medium. (author)

  1. Selective Incorporation of Nitrile-Based Infrared Probes into Proteins via Cysteine Alkylation

    OpenAIRE

    Jo, Hyunil; Culik, Robert M.; Korendovych, Ivan V.; DeGrado, William F.; Gai, Feng

    2010-01-01

    The nitrile stretching vibration is increasingly used as a sensitive infrared probe of local protein environments. However, site-specific incorporation of a nitrile moiety into proteins is difficult. Here we show that various aromatic nitriles can be easily incorporated into peptides and proteins via either thiol alkylation or arylation reaction.

  2. Dual function of a bee (Apis cerana) inhibitor cysteine knot peptide that acts as an antifungal peptide and insecticidal venom toxin.

    Science.gov (United States)

    Park, Hee Geun; Kyung, Seung Su; Lee, Kwang Sik; Kim, Bo Yeon; Choi, Yong Soo; Yoon, Hyung Joo; Kwon, Hyung Wook; Je, Yeon Ho; Jin, Byung Rae

    2014-12-01

    Inhibitor cysteine knot (ICK) peptides exhibit ion channel blocking, insecticidal, and antimicrobial activities, but currently, no functional roles for bee-derived ICK peptides have been identified. In this study, a bee (Apis cerana) ICK peptide (AcICK) that acts as an antifungal peptide and as an insecticidal venom toxin was identified. AcICK contains an ICK fold that is expressed in the epidermis, fat body, or venom gland and is present as a 6.6-kDa peptide in bee venom. Recombinant AcICK peptide (expressed in baculovirus-infected insect cells) bound directly to Beauveria bassiana and Fusarium graminearum, but not to Escherichia coli or Bacillus thuringiensis. Consistent with these findings, AcICK showed antifungal activity, indicating that AcICK acts as an antifungal peptide. Furthermore, AcICK expression is induced in the fat body and epidermis after injection with B. bassiana. These results provide insight into the role of AcICK during the innate immune response following fungal infection. Additionally, we show that AcICK has insecticidal activity. Our results demonstrate a functional role for AcICK in bees: AcICK acts as an antifungal peptide in innate immune reactions in the body and as an insecticidal toxin in venom. The finding that the AcICK peptide functions with different mechanisms of action in the body and in venom highlights the two-pronged strategy that is possible with the bee ICK peptide. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Perspective of Use of Antiviral Peptides against Influenza Virus

    Directory of Open Access Journals (Sweden)

    Sylvie Skalickova

    2015-10-01

    Full Text Available The threat of a worldwide influenza pandemic has greatly increased over the past decade with the emergence of highly virulent avian influenza strains. The increased frequency of drug-resistant influenza strains against currently available antiviral drugs requires urgent development of new strategies for antiviral therapy, too. The research in the field of therapeutic peptides began to develop extensively in the second half of the 20th century. Since then, the mechanisms of action for several peptides and their antiviral prospect received large attention due to the global threat posed by viruses. Here, we discussed the therapeutic properties of peptides used in influenza treatment. Peptides with antiviral activity against influenza can be divided into three main groups. First, entry blocker peptides such as a Flupep that interact with influenza hemagglutinin, block its binding to host cells and prevent viral fusion. Second, several peptides display virucidal activity, disrupting viral envelopes, e.g., Melittin. Finally, a third set of peptides interacts with the viral polymerase complex and act as viral replication inhibitors such as PB1 derived peptides. Here, we present a review of the current literature describing the antiviral activity, mechanism and future therapeutic potential of these influenza antiviral peptides.

  4. Recent Advances in Target Characterization and Identification by Photoaffinity Probes

    Directory of Open Access Journals (Sweden)

    Sang J. Chung

    2013-08-01

    Full Text Available Target identification of biologically active molecules such as natural products, synthetic small molecules, peptides, and oligonucleotides mainly relies on affinity chromatography, activity-based probes, or photoaffinity labeling (PAL. Amongst them, activity-based probes and PAL have offered great advantages in target identification technology due to their ability to form covalent bonds with the corresponding targets. Activity-based probe technology mainly relies on the chemical reactivity of the target proteins, thereby limiting the majority of the biological targets to enzymes or proteins which display reactive residues at the probe-binding site. In general, the probes should bear a reactive moiety such as an epoxide, a Michael acceptor, or a reactive alkyl halide in their structures. On the other hand, photoaffinity probes (PAPs are composed of a target-specific ligand and a photoactivatable functional group. When bound to the corresponding target proteins and activated with wavelength-specific light, PAPs generate highly reactive chemical species that covalently cross-link proximal amino acid residues. This process is better known as PAL and is widely employed to identify cellular targets of biologically active molecules. This review highlights recent advances in target identification by PAL, with a focus on the structure and chemistry of the photoaffinity probes developed in the recent decade, coupled to the target proteins identified using these probes.

  5. Protein interaction networks by proteome peptide scanning.

    Directory of Open Access Journals (Sweden)

    Christiane Landgraf

    2004-01-01

    Full Text Available A substantial proportion of protein interactions relies on small domains binding to short peptides in the partner proteins. Many of these interactions are relatively low affinity and transient, and they impact on signal transduction. However, neither the number of potential interactions mediated by each domain nor the degree of promiscuity at a whole proteome level has been investigated. We have used a combination of phage display and SPOT synthesis to discover all the peptides in the yeast proteome that have the potential to bind to eight SH3 domains. We first identified the peptides that match a relaxed consensus, as deduced from peptides selected by phage display experiments. Next, we synthesized all the matching peptides at high density on a cellulose membrane, and we probed them directly with the SH3 domains. The domains that we have studied were grouped by this approach into five classes with partially overlapping specificity. Within the classes, however, the domains display a high promiscuity and bind to a large number of common targets with comparable a