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Sample records for alpha5beta1 antagonistic peptide

  1. Breast cancer cells in three-dimensional culture display an enhanced radioresponse after coordinate targeting of integrin alpha5beta1 and fibronectin.

    Science.gov (United States)

    Nam, Jin-Min; Onodera, Yasuhito; Bissell, Mina J; Park, Catherine C

    2010-07-01

    Tactics to selectively enhance cancer radioresponse are of great interest. Cancer cells actively elaborate and remodel their extracellular matrix (ECM) to aid in survival and progression. Previous work has shown that beta1-integrin inhibitory antibodies can enhance the growth-inhibitory and apoptotic responses of human breast cancer cell lines to ionizing radiation, either when cells are cultured in three-dimensional laminin-rich ECM (3D lrECM) or grown as xenografts in mice. Here, we show that a specific alpha heterodimer of beta1-integrin preferentially mediates a prosurvival signal in human breast cancer cells that can be specifically targeted for therapy. 3D lrECM culture conditions were used to compare alpha-integrin heterodimer expression in malignant and nonmalignant cell lines. Under these conditions, we found that expression of alpha5beta1-integrin was upregulated in malignant cells compared with nonmalignant breast cells. Similarly, we found that normal and oncofetal splice variants of fibronectin, the primary ECM ligand of alpha5beta1-integrin, were also strikingly upregulated in malignant cell lines compared with nonmalignant acini. Cell treatment with a peptide that disrupts the interactions of alpha5beta1-integrin with fibronectin promoted apoptosis in malignant cells and further heightened the apoptotic effects of radiation. In support of these results, an analysis of gene expression array data from breast cancer patients revealed an association of high levels of alpha5-integrin expression with decreased survival. Our findings offer preclinical validation of fibronectin and alpha5beta1-integrin as targets for breast cancer therapy. Copyright 2010 AACR.

  2. Endothelial-monocyte activating polypeptide II alters fibronectin based endothelial cell adhesion and matrix assembly via alpha5 beta1 integrin

    International Nuclear Information System (INIS)

    Schwarz, Margaret A.; Zheng, Hiahua; Liu, Jie; Corbett, Siobhan; Schwarz, Roderich E.

    2005-01-01

    Mature Endothelial-Monocyte Activating Polypeptide (mEMAP) II functions as a potent antiangiogenic peptide. Although the anti-tumor effect of mEMAP II has been described, little is known regarding its mechanism of action. Observations that mEMAP II induced apoptosis only in a subset of migrating and proliferating endothelial cells (EC) suggests a targeted effect on cells engaged in angiogenic activities which are known to rely upon cell adhesion and migration. Indeed, we demonstrate that mEMAP II inhibited fibronectin (FN) dependent microvascular EC (MEC) adhesion and spreading and we show that this depends upon the alpha5 beta1 integrin. Immunofluorescence analysis demonstrated that mEMAP II-dependent blockade of FN-alpha5 beta1 interactions was associated with disassembly of both actin stress fiber networks and FN matrix. These findings suggest that mEMAP II blocks MEC adhesion and spreading on fibronectin, via a direct interaction with the integrin alpha5 beta1, thus implicating that alpha5 integrin may be a mediator of mEMAP II's antiangiogenic function

  3. Vesicle-associated membrane protein 2 mediates trafficking of {alpha}5{beta}1 integrin to the plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Nazarul [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States); Hu, Chuan, E-mail: chuan.hu@louisville.edu [Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 319 Abraham Flexner Way, Room 515, Louisville, KY 40202 (United States)

    2010-01-01

    Integrins are major receptors for cell adhesion to the extracellular matrix (ECM). As transmembrane proteins, the levels of integrins at the plasma membrane or the cell surface are ultimately determined by the balance between two vesicle trafficking events: endocytosis of integrins at the plasma membrane and exocytosis of the vesicles that transport integrins. Here, we report that vesicle-associated membrane protein 2 (VAMP2), a SNARE protein that mediates vesicle fusion with the plasma membrane, is involved in the trafficking of {alpha}5{beta}1 integrin. VAMP2 was present on vesicles containing endocytosed {beta}1 integrin. Small interfering RNA (siRNA) silencing of VAMP2 markedly reduced cell surface {alpha}5{beta}1 and inhibited cell adhesion and chemotactic migration to fibronectin, the ECM ligand of {alpha}5{beta}1, without altering cell surface expression of {alpha}2{beta}1 integrin or {alpha}3{beta}1 integrin. By contrast, silencing of VAMP8, another SNARE protein, had no effect on cell surface expression of the integrins or cell adhesion to fibronectin. In addition, VAMP2-mediated trafficking is involved in cell adhesion to collagen but not to laminin. Consistent with disruption of integrin functions in cell proliferation and survival, VAMP2 silencing diminished proliferation and triggered apoptosis. Collectively, these data indicate that VAMP2 mediates the trafficking of {alpha}5{beta}1 integrin to the plasma membrane and VAMP2-dependent integrin trafficking is critical in cell adhesion, migration and survival.

  4. Alpha5beta1 integrin-fibronectin interactions specify liquid to solid phase transition of 3D cellular aggregates.

    Directory of Open Access Journals (Sweden)

    Carlos E Caicedo-Carvajal

    2010-07-01

    Full Text Available Tissue organization during embryonic development and wound healing depends on the ability of cells on the one hand to exchange adhesive bonds during active rearrangement and on the other to become fixed in place as tissue homeostasis is reached. Cells achieve these contradictory tasks by regulating either cell-cell adhesive bonds, mediated by cadherins, or cell-extracellular matrix (ECM connections, regulated by integrins. Integrin alpha5beta1 and soluble fibronectin (sFN are key players in cell-ECM force generation and in ECM polymerization. Here, we explore the interplay between integrin alpha5beta1 and sFN and its influence on tissue mechanical properties and cell sorting behavior.We generated a series of cell lines varying in alpha5beta1 receptor density. We then systematically explored the effects of different sFN concentrations on aggregate biomechanical properties using tissue surface tensiometry. We found previously unreported complex behaviors including the observation that interactions between fibronectin and integrin alpha5beta1 generates biphasic tissue cohesion profiles. Specifically, we show that at constant sFn concentration, aggregate cohesion increases linearly as alpha5beta1 receptor density is increased from low to moderate levels, producing a transition from viscoelastic-liquid to pseudo viscoelastic-solid behavior. However, further increase in receptor density causes an abrupt drop in tissue cohesion and a transition back to viscoelastic-liquid properties. We propose that this may be due to depletion of sFn below a critical value in the aggregate microenvironment at high alpha5beta1 levels. We also show that differential expression of alpha5beta1 integrin can promote phase-separation between cells.The interplay between alpha5-integrin and sFn contributes significantly to tissue cohesion and, depending on their level of expression, can mediate a shift from liquid to elastic behavior. This interplay represents a tunable level

  5. A region in urokinase plasminogen receptor domain III controlling a functional association with alpha5beta1 integrin and tumor growth

    DEFF Research Database (Denmark)

    Chaurasia, Pratima; Aguirre-Ghiso, Julio; Liang, Olin D

    2006-01-01

    Highly expressed urokinase plasminogen activator receptor (uPAR) can interact with alpha5beta1 integrin leading to persistent ERK activation and tumorigenicity. Disrupting this interaction reduces ERK activity, forcing cancer cells into dormancy. We identified a site in uPAR domain III that is in......Highly expressed urokinase plasminogen activator receptor (uPAR) can interact with alpha5beta1 integrin leading to persistent ERK activation and tumorigenicity. Disrupting this interaction reduces ERK activity, forcing cancer cells into dormancy. We identified a site in uPAR domain III...

  6. The fibronectin-binding integrins alpha5beta1 and alphavbeta3 differentially modulate RhoA-GTP loading, organization of cell matrix adhesions, and fibronectin fibrillogenesis

    DEFF Research Database (Denmark)

    Danen, Erik H J; Sonneveld, Petra; Brakebusch, Cord

    2002-01-01

    We have studied the formation of different types of cell matrix adhesions in cells that bind to fibronectin via either alpha5beta1 or alphavbeta3. In both cases, cell adhesion to fibronectin leads to a rapid decrease in RhoA activity. However, alpha5beta1 but not alphavbeta3 supports high levels...... subunits, we find that the extracellular domain of beta1 controls RhoA activity. By expressing both beta1 and beta3 at high levels, we show that beta1-mediated control of the levels of beta3 is important for the distribution of focal contacts. Our findings demonstrate that the pattern of fibronectin...... receptors expressed on a cell dictates the ability of fibronectin to stimulate RhoA-mediated organization of cell matrix adhesions....

  7. Regulation of ionizing radiation-induced adhesion of breast cancer cells to fibronectin by alpha5beta1 integrin.

    Science.gov (United States)

    Lee, Shin Hee; Cheng, Huiwen; Yuan, Ye; Wu, Shiyong

    2014-06-01

    Ionizing radiation (IR) is commonly used for cancer therapy, however, its potential influence on cancer metastatic potential remains controversial. In this study, we elucidated the role of integrins in regulation of IR-altered adhesion between breast cancer cells and extracellular matrix (ECM) proteins, which is a key step in the initial phase of metastasis. Our data suggest that the extent of effect that ionizing radiation had on cell adhesion depended on the genetic background of the breast cancer cells. Ionizing radiation was a better adhesion inducer for p53-mutated cells, such as MDA-MB-231 cells, than for p53 wild-type cells, such as MCF-7 cells. While IR-induced adhesions between MDA-MB-231 cells to fibronectin, laminin, collagen I and collagen IV, only blocking of the adhesion between α5β1 integrin and fibronectin using anti-α5β1 integrin antibody could completely inhibit the radiation-induced adhesion of the cells. A soluble Arg-Gly-Asp peptide, the binding motif for fibronectin binding integrins, could also reduce the adhesion of the cells to fibronectin with or without ionizing radiation exposure. The inhibition of the cell-fibronectin interaction also affected, but did not always correlate with, transwell migration of the cancer cells. In addition, our data showed that the total expression of α5 integrin and surface expression of α5β1 integrin were increased in the cells treated with ionizing radiation. The increased surface expression of α5β1 integrin, along with the adhesion between the cells and fibronectin, could be inhibited by both ataxia telangiectasia mutated (ATM) and Rad3-related (ATR) kinase inhibitors. These results suggested that ATM/ATR-mediated surface expression of α5β1 integrin might play a central role in regulation of ionizing radiation-altered adhesion.

  8. Alpha 4 beta 1 and alpha 5 beta 1 are differentially expressed during myelopoiesis and mediate the adherence of human CD34+ cells to fibronectin in an activation-dependent way

    NARCIS (Netherlands)

    Kerst, J. M.; Sanders, J. B.; Slaper-Cortenbach, I. C.; Doorakkers, M. C.; Hooibrink, B.; van Oers, R. H.; von dem Borne, A. E.; van der Schoot, C. E.

    1993-01-01

    To study the receptors involved in the interaction between extracellular matrix proteins and hematopoietic progenitor cells, we analyzed the expression of beta 1 integrins on CD34+ bone marrow cells by means of immunoflowcytometry. Alpha 4 beta 1 and alpha 5 beta 1 were expressed, whereas alpha 1

  9. Enhancement of the adhesive and spreading potentials of ovarian carcinoma RMG-1 cells due to increased expression of integrin alpha5beta1 with the Lewis Y-structure on transfection of the alpha1,2-fucosyltransferase gene.

    Science.gov (United States)

    Yan, Li-Mei; Lin, Bei; Zhu, Lian-Cheng; Hao, Ying-Ying; Qi, Yue; Wang, Chang-Zhi; Gao, Song; Liu, Shui-Ce; Zhang, Shu-Lan; Iwamori, Masao

    2010-07-01

    Le(Y) antigen is known to be associated with malignant properties including metastasis and a poor prognosis of ovarian carcinomas. To clarify the mechanisms underling these properties, we established ovarian carcinoma-derived cells exhibiting enhanced expression of Le(Y) by transfection with alpha1,2-fucosyltransferase and compared their cellular properties with those of the original cells. So the human alpha1,2-fucosyltransferase gene was transfected into ovarian carcinoma-derived RMG-1 cells, which are known to contain Le(X), a precursor of Le(Y), and RMG-1-hFUT cells exhibiting enhanced expression of Le(Y) were established by selection with anti-Le(Y) antibodies, and their adhesive and spreading potentials on fibronectin-coated plates were compared with those of RMG-1 cells. Results showed that the relative expression of Le(Y) in RMG-1-hFUT cells was about 20-fold that in RMG-1 cells, and that of integrin alpha5beta1 and an integrin-mediated signal transduction molecule, focal adhesion kinase, was also increased in RMG-1-hFUT cells. Interestingly, anti-Le(Y) antibodies were revealed to immunoprecipitate integrin alpha5beta1, indicating that its oligosaccharides are composed of Le(Y), the amounts of which was substantially elevated in RMG-1-hFUT cells. The adhesion and spreading potentials on fibronectin-coated plates of RMG-1-hFUT cells were significantly enhanced in comparison to those of RMG-1 cells, and were greatly suppressed by anti-Le(Y) antibodies, indicating that Le(Y) is involved in the integrin-fibronectin interaction. These results suggested that transfection of the alpha1,2-fucosyltransferase gene into ovarian carcinoma-derived cells brought about elevated expression of integrin alpha5beta1 with Le(Y), resulting in enhancement of the adhesion and spreading potentials of cells through the integrin-fibronection interaction, which was inhibited by anti-Le(Y) antibodies. Thus, Le(Y) in integrin alpha5beta1 was thought to be involved in the enhanced cell

  10. Synthetic peptide antagonists of glucagon

    International Nuclear Information System (INIS)

    Unson, C.G.; Andreu, D.; Gurzenda, E.M.; Merrifield, R.B.

    1987-01-01

    Several glucagon analogs were synthesized in an effort to find derivatives that would bind with high affinity to the glucagon receptor of rat liver membranes but would not activate membrane-bound adenylate cyclase and, therefore, would serve as antagonists of the hormone. Measurements on a series of glucagon/secretin hybrids indicated that replacement of Asp 9 in glucagon by Glu 9 , found in secretin, was the important sequence difference in the N terminus of the two hormones. Further deletion of His 1 and introduction of a C-terminal amide resulted in des-His 1 -[Glu 9 ]glucagon amide, which had a 40% binding affinity relative to that of native glucagon but caused no detectable adenylate cyclase activation in the rat liver membrane. This antagonist completely inhibited the effect of a concentration of glucagon that alone gave a full agonist response. It had an inhibition index of 12. The pA 2 was 7.2. An attempt was made to relate conformation with receptor binding. The peptides were synthesized by solid-phase methods and purified to homogeneity by reverse-phase high-performance liquid chromatography on C 18 -silica columns

  11. Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site Definition and Plasma Stability

    Science.gov (United States)

    2015-11-01

    phosphatidylinositol 3’-kinase and its downstream signals in erbB-2- mediated transformation . Mol Cancer Res, 2003. 1(7): p. 551-60. PMID: 12754302 16. Aota S, Nomizu M... mediated invasion through noncovalent interaction with α5β1 receptors of SUM149PT and MDA-MB-231 metastatic human breast cancer cells, and laid the...foundation for detailed structure–activity relationship (SAR) studies for both peptides as inhibitors of α5β1– mediated metastatic breast cancer invasion

  12. Screening and Mechanism of Trapping Ligand Antagonist Peptide ...

    African Journals Online (AJOL)

    Purpose: The aim of the present study was to develop peptide H9 as an efficient antagonist of human cytomegalovirus (HCMV) chemokine receptor US28. Methods: US28 gene was amplified from HCMV, and a stable expression system was constructed using NIH/3T3 cells. Interaction between peptide H9 and receptor ...

  13. Recent Development of Non-Peptide GnRH Antagonists

    Directory of Open Access Journals (Sweden)

    Feng-Ling Tukun

    2017-12-01

    Full Text Available The decapeptide gonadotropin-releasing hormone, also referred to as luteinizing hormone-releasing hormone with the sequence (pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2 plays an important role in regulating the reproductive system. It stimulates differential release of the gonadotropins FSH and LH from pituitary tissue. To date, treatment of hormone-dependent diseases targeting the GnRH receptor, including peptide GnRH agonist and antagonists are now available on the market. The inherited issues associate with peptide agonists and antagonists have however, led to significant interest in developing orally active, small molecule, non-peptide antagonists. In this review, we will summarize all developed small molecule GnRH antagonists along with the most recent clinical data and therapeutic applications.

  14. Combining elements from two antagonists of formyl peptide receptor 2 generates more potent peptidomimetic antagonists

    DEFF Research Database (Denmark)

    Skovbakke, Sarah Line; Holdfeldt, Andre; Nielsen, Christina

    2017-01-01

    Structural optimization of a peptidomimetic antagonist of formyl peptide receptor 2 (FPR2) was explored by an approach involving combination of elements from the two most potent FPR2 antagonists described: a Rhodamine B-conjugated 10-residue gelsonin-derived peptide (i.e., PBP10, Rh......B-QRLFQVKGRR-OH) and the palmitoylated α-peptide/β-peptoid hybrid Pam-(Lys-βNspe)6-NH2. This generated an array of hybrid compounds from which a new subclass of receptor-selective antagonists was identified. The most potent representatives displayed activity in the low nanomolar range. The resulting stable and potent FPR2-selective...... antagonists (i.e., RhB-(Lys-βNphe)n-NH2; n = 4–6) are expected to become valuable tools in further elucidation of the physiological role of FPR2 in health and disease....

  15. Anti-inflammatory properties of a novel peptide interleukin 1 receptor antagonist

    DEFF Research Database (Denmark)

    Klementiev, Boris; Li, Shizhong; Korshunova, Irina

    2014-01-01

    Interleukin 1 (IL-1) is implicated in neuroinflammation, an essential component of neurodegeneration. We evaluated the potential anti-inflammatory effect of a novel peptide antagonist of IL-1 signaling, Ilantide.......Interleukin 1 (IL-1) is implicated in neuroinflammation, an essential component of neurodegeneration. We evaluated the potential anti-inflammatory effect of a novel peptide antagonist of IL-1 signaling, Ilantide....

  16. Design of potent and specific integrin antagonists. Peptide antagonists with high specificity for glycoprotein IIb-IIIa.

    Science.gov (United States)

    Scarborough, R M; Naughton, M A; Teng, W; Rose, J W; Phillips, D R; Nannizzi, L; Arfsten, A; Campbell, A M; Charo, I F

    1993-01-15

    Members of the snake venon-derived, "disintegrin" peptide family containing the Arg-Gly-Asp (RGD) amino acid sequence are among the most potent inhibitors of the binding of adhesive proteins to platelet glycoprotein (GP) IIb-IIIa. However, GPIIb-IIIa antagonists containing the RGD sequence are not integrin specific and inhibit the adhesive functions of many other RGD-dependent integrins. The single disintegrin peptide, barbourin, containing a conservative amino acid substitution of Lys (K) for Arg (R) in the RGD sequence, is however, highly specific for GPIIb-IIIa. Using this information we have tested the hypothesis that both structural and conformational elements of barbourin are important for its high affinity and selectivity for platelet GPIIb-IIIa by synthesizing a series of conformationally constrained, disulfide-bridged peptides containing the KGD amino acid sequence. Incorporation of the KGD sequence into a cyclic peptide template, followed by systematic optimization of the cyclic ring size, optimization of secondary hydrophobic binding site interactions, and the derivatization of the lysyl side chain functionality of the KGD sequence has resulted in peptide analogs which display inhibitory potency and GPIIb-IIIa selectivity comparable to that of barbourin. This study demonstrates that the specificity and potency of the disintegrin family of antagonists, in particular barbourin, can be mimicked by small, conformationally restrained peptides.

  17. Interactions of Gastrointestinal Peptides: Ghrelin and Its Anorexigenic Antagonists

    Directory of Open Access Journals (Sweden)

    Anna-Sophia Wisser

    2010-01-01

    Full Text Available Food intake behaviour and energy homeostasis are strongly regulated by a complex system of humoral factors and nerval structures constituting the brain-gut-axis. To date the only known peripherally produced and centrally acting peptide that stimulates food intake is ghrelin, which is mainly synthesized in the stomach. Recent data indicate that the orexigenic effect of ghrelin might be influenced by other gastrointestinal peptides such as cholecystokinin (CCK, bombesin, desacyl ghrelin, peptide YY (PYY, as well as glucagon-like peptide (GLP. Therefore, we will review on the interactions of ghrelin with several gastrointestinal factors known to be involved in appetite regulation in order to elucidate the interdependency of peripheral orexigenic and anorexigenic peptides in the control of appetite.

  18. Dynamics of urokinase receptor interaction with Peptide antagonists studied by amide hydrogen exchange and mass spectrometry

    DEFF Research Database (Denmark)

    Jørgensen, Thomas J D; Gårdsvoll, Henrik; Danø, Keld

    2004-01-01

    Using amide hydrogen exchange combined with electrospray ionization mass spectrometry, we have in this study determined the number of amide hydrogens on several peptides that become solvent-inaccessible as a result of their high-affinity interaction with the urokinase-type plasminogen activator...... receptor (uPAR). These experiments reveal that at least six out of eight amide hydrogens in a synthetic nine-mer peptide antagonist (AE105) become sequestered upon engagement in uPAR binding. Various uPAR mutants with decreased affinity for this peptide antagonist gave similar results, thereby indicating...... that deletion of the favorable interactions involving the side chains of these residues in uPAR does not affect the number of hydrogen bonds established by the main chain of the peptide ligand. The isolated growth factor-like domain (GFD) of the cognate serine protease ligand for uPAR showed 11 protected amide...

  19. Quantitative Structure-Activity Relationships and Docking Studies of Calcitonin Gene-Related Peptide Antagonists

    DEFF Research Database (Denmark)

    Jenssen, Håvard; Mehrabian, Mohadeseh; Kyani, Anahita

    2012-01-01

    of calcitonin gene-related peptide antagonists was performed using a panel of physicochemical descriptors. The computational studies evaluated different variable selection techniques and demonstrated shuffling stepwise multiple linear regression to be superior over genetic algorithm-multiple linear regression....... The linear quantitative structure-activity relationship model revealed better statistical parameters of cross-validation in comparison with the non-linear support vector regression technique. Implementing only five peptide descriptors into this linear quantitative structure-activity relationship model...

  20. Peptide antagonists of the human urokinase receptor and method for selecting them

    DEFF Research Database (Denmark)

    2006-01-01

    A novel set of inhibitors of the binding interaction between human urokinase plasminogen activator (uPA) and its cell surface receptor (uPAR) has been developed. The inhibitors comprise of peptide fragments, monomeric or in multiple copies attached to a common scaffold, in which the amino acid se...... are antagonistic....

  1. Impact of peptide ghrelin antagonists on metabolic syndrome in female obese mice

    Czech Academy of Sciences Publication Activity Database

    Maletínská, Lenka; Železná, Blanka; Matyšková, Resha; Maixnerová, Jana; Pýchová, Miroslava; Špolcová, Andrea; Blechová, Miroslava; Jurcovicová, J.; Haluzník, M.

    2010-01-01

    Roč. 16, S1 (2010), s. 116-117 ISSN 1075-2617. [European Peptide Symposium /31./. 05.09.2010-09.09.2010, Copenhagen] R&D Projects: GA ČR GA303/09/0744 Institutional research plan: CEZ:AV0Z40550506 Keywords : DIO * OVX * mice * ghrelin antagonist Subject RIV: CC - Organic Chemistry

  2. Effect of the calcitonin gene-related peptide (CGRP) receptor antagonist telcagepant in human cranial arteries

    NARCIS (Netherlands)

    L. Edvinsson (Lars); K.Y. Chan (Kayi); S. Eftekhari; E. Nilsson (Elisabeth); R. de Vries (René); H. Säveland (Hans); C.M.F. Dirven (Clemens); A.H.J. Danser (Jan)

    2010-01-01

    textabstractIntroduction: Calcitonin gene-related peptide (CGRP) is a neuronal messenger in intracranial sensory nerves and is considered to play a significant role in migraine pathophysiology. Materials and methods: We investigated the effect of the CGRP receptor antagonist, telcagepant, on

  3. Identification of ligand-selective peptidic ActRIIB-antagonists using phage display technology

    Directory of Open Access Journals (Sweden)

    Kotaro Sakamoto

    2017-09-01

    Full Text Available ActRIIB (activin receptor type-2B is an activin receptor subtype constitutively expressed in the whole body, playing a role in cellular proliferation, differentiation, and metabolism. For its various physiological activities, ActRIIB interacts with activin and multiple other ligands including myostatin (MSTN, growth differentiation factor 11 (GDF11, and bone morphogenetic protein 9 (BMP9. Notably, the protein-protein interaction (PPI between ActRIIB and MSTN negatively controls muscular development. Therefore, this PPI has been targeted for effective treatment of muscle degenerative diseases such as muscular dystrophy and sarcopenia. Here, we report the identification of ligand-selective peptidic ActRIIB-antagonists by phage display technology. Our peptides bound to the extracellular domain of ActRIIB, inhibited PPIs between ActRIIB expressed on the cell surface and its ligands, and subsequently suppressed activation of Smad that serves as the downstream signal of the ActRIIB pathway. Interestingly, these peptidic antagonists displayed different ligand selectivities; the AR2mini peptide inhibited multiple ligands (activin A, MSTN, GDF11, and BMP9, AR9 inhibited MSTN and GDF11, while AR8 selectively inhibited MSTN. This is the first report of artificial peptidic ActRIIB-antagonists possessing ligand-selectivity.

  4. CXCR4-antagonist Peptide R-liposomes for combined therapy against lung metastasis

    Science.gov (United States)

    Ieranò, Caterina; Portella, Luigi; Lusa, Sara; Salzano, Giuseppina; D'Alterio, Crescenzo; Napolitano, Maria; Buoncervello, Maria; Macchia, Daniele; Spada, Massimo; Barbieri, Antonio; Luciano, Antonio; Barone, Maria Vittoria; Gabriele, Lucia; Caraglia, Michele; Arra, Claudio; De Rosa, Giuseppe; Scala, Stefania

    2016-03-01

    The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide R were developed (PL-Peptide R). In vitro PL-Peptide R efficiently inhibited CXCR4-dependent migration and in vivo it significantly reduced lung metastases and increased overall survival in B16-CXCR4 injected C57BL/6 mice. To evaluate if PL-Peptide R could also be a drug delivery system for CXCR4 expressing tumors, the PL-Peptide R was loaded with doxorubicin (DOX) (PL-Peptide R-DOX). PL-Peptide R-DOX efficiently delivered DOX to CXCR4 expressing cell lines with a consequent decrease in the DOX IC50 efficient dose. In vivo, B16-CXCR4 injected C57BL/6 mice treated with PL-Peptide R-DOX developed fewer lung metastases compared to PL-DOX treated mice. This work provides the proof-of-concept to prevent metastasis by using combined nanomedicine.The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide

  5. Differential binding of urokinase and peptide antagonists to the urokinase receptor

    DEFF Research Database (Denmark)

    Engelholm, L H; Behrendt, N

    2001-01-01

    for the invasion of cancer cells, thus making uPAR a potential target for anti-invasive therapy based on binding antagonists. A remarkable property of the uPA-uPAR system is a pronounced species specificity in ligand recognition. We have now cloned and studied uPAR from four primate species and show that even......The urokinase plasminogen activator receptor (uPAR) is a membrane protein active in localizing the plasminogen activation cascade system on the cell surface. The resulting pericellular proteolytic activity is responsible for degradation reactions in the extracellular matrix that are needed....... These findings aid the elucidation of the structure/function relationship of uPAR and, unexpectedly, identify a structural distinction governing the binding of uPA and a very similar peptide antagonist....

  6. Bombesin peptide antagonist for target-selective delivery of liposomal doxorubicin on cancer cells.

    Science.gov (United States)

    Accardo, Antonella; Mansi, Rosalba; Salzano, Giuseppina; Morisco, Anna; Aurilio, Michela; Parisi, Antonio; Maione, Francesco; Cicala, Carla; Ziaco, Barbara; Tesauro, Diego; Aloj, Luigi; De Rosa, Giuseppe; Morelli, Giancarlo

    2012-11-21

    Purpose: This study addresses novel peptide modified liposomal doxorubicin to specifically target tissues overexpressing bombesin (BN) receptors. Methods: DOTA-(AEEA)(2)-peptides containing the [7-14]bombesin and the new BN-AA1 sequence have been synthesized to compare their binding properties and in serum stabilities. The amphiphilic peptide derivative (MonY-BN-AA1) containing BN-AA1, a hydrophobic moiety, polyethylenglycole (PEG), and diethylenetriaminepentaacetate (DTPA), has been synthesized. Liposomes have been obtained by mixing of MonY-BN-AA1 with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). Results: Both (111)In labeled peptide derivatives present nanomolar Kd to PC-3 cells. (177)Lu labeled peptide DOTA-(AEEA)(2)-BN-AA1 is very stable (half-life 414.1 h), while DOTA-(AEEA)(2)-BN, shows a half-life of 15.5 h. In vivo studies on the therapeutic efficacy of DSPC/MonY-BN-AA1/Dox in comparison to DSPC/MonY-BN/Dox, were performed in PC-3 xenograft bearing mice. Both formulations showed similar tumor growth inhibition (TGI) compared to control animals treated with non-targeted DSPC/Dox liposomes or saline solution. For DSPC/MonY-BN-AA1/Dox the maximum effect was observed 19 days after treatment. Conclusions: DSPC/MonY-BN-AA1/Dox nanovectors confirm the ability to selectively target and provide therapeutic efficacy in mice. The lack of receptor activation and possible acute biological side effects provided by using the AA1 antagonist bombesin sequence should provide safe working conditions for further development of this class of drug delivery vehicles.

  7. Beta-methyl substitution of cyclohexylalanine in Dmt-Tic-Cha-Phe peptides results in highly potent delta opioid antagonists.

    Science.gov (United States)

    Tóth, Géza; Ioja, Eniko; Tömböly, Csaba; Ballet, Steven; Tourwé, Dirk; Péter, Antal; Martinek, Tamás; Chung, Nga N; Schiller, Peter W; Benyhe, Sándor; Borsodi, Anna

    2007-01-25

    The opioid peptide TIPP (H-Tyr-Tic-Phe-Phe-OH, Tic:1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) was substituted with Dmt (2',6'-dimethyltyrosine) and a new unnatural amino acid, beta-MeCha (beta-methyl-cyclohexylalanine). This double substitution led to a new series of opioid peptides displaying subnanomolar delta antagonist activity and mu agonist or antagonist properties depending on the configuration of the beta-MeCha residue. The most promising analog, H-Dmt-Tic-(2S,3S)-beta-MeCha-Phe-OH was a very selective delta antagonist both in the mouse vas deferens (MVD) assay (Ke = 0.241 +/- 0.05 nM) and in radioligand binding assay (K i delta = 0.48 +/- 0.05 nM, K i mu/K i delta = 2800). The epimeric peptide H-Dmt-Tic-(2S,3R)-beta-MeCha-Phe-OH and the corresponding peptide amide turned out to be mixed partial mu agonist/delta antagonists in the guinea pig ileum and MVD assays. Our results constitute further examples of the influence of Dmt and beta-methyl substitution as well as C-terminal amidation on the potency, selectivity, and signal transduction properties of TIPP related peptides. Some of these compounds represent valuable pharmacological tools for opioid research.

  8. The detection of a synthetic Interleukin-1 receptor antagonist peptide in a seized product from a racing stable.

    Science.gov (United States)

    Levina, Vita; Timms, Mark; Vine, John; Steel, Rohan

    2016-09-01

    A synthetic Interleukin-1 receptor antagonist peptide with the sequence Acetyl-Phe-Glu-Trp-Thr-Pro-Gly-Tyr-Trp-Gln-Pro-Tyr-Ala-Leu-Pro-Leu-OH has been identified in a vial seized during a stable inspection. The use of peptide-based Interleukin-1 receptor antagonists as anti-inflammatory agents has not been previously reported, making this peptide the first in a new class of sports doping peptides. The peptide has been characterized by high-resolution mass spectrometry and a detection method developed based on solid-phase extraction and liquid chromatography - triple quadrupole mass spectrometry. Using in vitro and in vivo models to study the properties of the peptide after administration, the peptide was shown to be highly unstable in plasma and was not detected in urine after administration in a rat. The poor stability of the peptide makes detection challenging but also suggests that it has limited effectiveness as an anti-inflammatory drug. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Self-assembly of fibronectin mimetic peptide-amphiphile nanofibers

    Science.gov (United States)

    Rexeisen, Emilie Lynn

    Many therapeutic strategies incorporate peptides into their designs to mimic the natural protein ligands found in vivo. A few examples are the short peptide sequences RGD and PHSRN that mimic the primary and synergy-binding domains of the extracellular matrix protein, fibronectin, which is recognized by the cell surface receptor, alpha5beta 1 integrin. Even though scaffold modification with biomimetic peptides remains one of the most promising approaches for tissue engineering, the use of these peptides in therapeutic tissue-engineered products and drug delivery systems available on the commercial market is limited because the peptides are not easily able to mimic the natural protein. The design of a peptide that can effectively target the alpha5beta1 integrin would greatly increase biomimetic scaffold therapeutic potential. A novel peptide containing both the RGD primary binding domain and PHSRN synergy-binding domain for fibronectin joined with the appropriate linker should bind alpha 5beta1 integrin more efficiently and lead to greater cell adhesion over RGD alone. Several fibronectin mimetic peptides were designed and coupled to dialkyl hydrocarbon tails to make peptide-amphiphiles. The peptides contained different linkers connecting the two binding domains and different spacers separating the hydrophobic tails from the hydrophilic headgroups. The peptide-amphiphiles were deposited on mica substrates using the Langmuir-Blodgett technique. Langmuir isotherms indicated that the peptide-amphiphiles that contained higher numbers of serine residues formed a more tightly packed monolayer, but the increased number of serines also made transferring the amphiphiles to the mica substrate more difficult. Atomic force microscopy (AFM) images of the bilayers showed that the headgroups might be bent, forming small divots in the surface. These divots may help expose the PHSRN synergy-binding domain. Parallel studies undertaken by fellow group members showed that human

  10. Effects of matrix metalloproteinase inhibitor doxycycline and CD147 antagonist peptide-9 on gallbladder carcinoma cell lines.

    Science.gov (United States)

    Wang, Shihang; Liu, Chao; Liu, Xinjiang; He, Yanxin; Shen, Dongfang; Luo, Qiankun; Dong, Yuxi; Dong, Haifeng; Pang, Zhigang

    2017-10-01

    Gallbladder carcinoma is the most common and aggressive malignancy of the biliary tree and highly expresses CD147, which is closely related to disease prognosis in a variety of human cancers. Doxycycline exhibited anti-tumor properties in many cancer cells. CD147 antagonist peptide-9 is a polypeptide and can specifically bind to CD147. The effect of these two drugs on gallbladder cancer cells has not been studied. The aim of this study is to investigate the effect of doxycycline and antagonist peptide-9 on gallbladder carcinoma cells and the possible mechanism of inhibition on cancer cell of doxycycline. To investigate the effects of doxycycline and antagonist peptide-9 on gallbladder carcinoma cells (GBC-SD and SGC-996), cell proliferation, CD147 expression, and early-stage apoptosis rate were measured after treated with doxycycline. Matrix metalloproteinase-2 and matrix metalloproteinase-9 activities were measured after treated with different concentrations of doxycycline, antagonist peptide-9, and their combination. The results demonstrated that doxycycline inhibited cell proliferation, reduced CD147 expression level, and induced an early-stage apoptosis response in GBC-SD and SGC-996 cells. The matrix metalloproteinase-2 and matrix metalloproteinase-9 activities were inhibited by antagonist peptide-9 and doxycycline, and the inhibitory effects were enhanced by combined drugs in gallbladder carcinoma cell lines. Taken together, doxycycline showed inhibitory effects on gallbladder carcinoma cell lines and reduced the expression of CD147, and this may be the mechanism by which doxycycline inhibits cancer cells. This study provides new information and tries to implement the design of adjuvant therapy method for gallbladder carcinoma.

  11. Antagonistic effect of disulfide-rich peptide aptamers selected by cDNA display on interleukin-6-dependent cell proliferation

    International Nuclear Information System (INIS)

    Nemoto, Naoto; Tsutsui, Chihiro; Yamaguchi, Junichi; Ueno, Shingo; Machida, Masayuki; Kobayashi, Toshikatsu; Sakai, Takafumi

    2012-01-01

    Highlights: ► Disulfide-rich peptide aptamer inhibits IL-6-dependent cell proliferation. ► Disulfide bond of peptide aptamer is essential for its affinity to IL-6R. ► Inhibitory effect of peptide depends on number and pattern of its disulfide bonds. -- Abstract: Several engineered protein scaffolds have been developed recently to circumvent particular disadvantages of antibodies such as their large size and complex composition, low stability, and high production costs. We previously identified peptide aptamers containing one or two disulfide-bonds as an alternative ligand to the interleukin-6 receptor (IL-6R). Peptide aptamers (32 amino acids in length) were screened from a random peptide library by in vitro peptide selection using the evolutionary molecular engineering method “cDNA display”. In this report, the antagonistic activity of the peptide aptamers were examined by an in vitro competition enzyme-linked immunosorbent assay (ELISA) and an IL-6-dependent cell proliferation assay. The results revealed that a disulfide-rich peptide aptamer inhibited IL-6-dependent cell proliferation with similar efficacy to an anti-IL-6R monoclonal antibody.

  12. Coupling Reaction of Oligo p-Phenylene Ethynylene and Peptide Antagonist RM26 Labeling with 131

    Directory of Open Access Journals (Sweden)

    JIAN Yuan1,2;ZHOU Zhi-jun2;ZHUO Lian-gang2;ZHAO Peng2;LIAO Wei2;WANG Guan-quan2;LIU Ning1

    2016-08-01

    Full Text Available Investigations reveale that oligo p-phenylene ethynylene (OPE molecule can insert into cell membrane, which leads to its cellular internization capacility. Antagonists have high cancer cell affinity, high uptake in cancer cells and fast clearance in normal tissue, these capabilities have attracted much research interest in radiopharmaceutical development. Combining the strong cell-penetrating ability and high affinity of Gastrin-releasing peptide which is overexpressed in the PC-3 cells, the thesis designed and synthesized unsymmetric OPE(NH2 molecule. Then the OPE(NH2 molecule was followed by the coupling reaction with RM26 peptide to obtain the OPE-RM26, and (Tyr3-RM26 was also got for controling study. After that, the (Tyr3-RM26 and OPE-RM26 were radiolabeled with I-131 to give high radiolabeling yields that could up to 95%. The radiolabeling compound was stable after 24 h storage at room temperature. These labeled compounds are ready for animal in-vivo experiment. It is expected that OPE-RM26-131I has multi-properties with targeting membrane crossing fire of radioactive elements. The molecule may fast travel to the target tissue and bind to GRP receptor and internalized into cancer cells. The casade process will give rise to its cancer cell toxicity due to longer retention and more killing effect of ray’s irradiation to cancer cells. In this way, OPE-RM26-131I can achieve better anti-cancer ability.

  13. PET imaging detection of macrophages with a formyl peptide receptor antagonist

    International Nuclear Information System (INIS)

    Zhang, Yi; Kundu, Bijoy; Zhong, Min; Huang, Tao; Li, Jing; Chordia, Mahendra D.; Chen, Mei-Hua; Pan, Dongfeng; He, Jiang; Shi, Weibin

    2015-01-01

    Macrophages are a major inflammatory cell type involved in the development and progression of many important chronic inflammatory diseases. We previously found that apolipoprotein E-deficient (Apoe −/− ) mice with the C57BL/6 (B6) background develop type 2 diabetes mellitus (T2DM) and accelerated atherosclerosis when fed a Western diet and that there are increased macrophage infiltrations in pancreatic islets and aorta. The formyl peptide receptor 1 (FPR1) is abundantly expressed on the surface of macrophages. The purpose of this study was to evaluate the applicability of cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), a natural FPR1 antagonist, to detection of macrophages in the pancreatic islets and aorta. 64 Cu labeled cFLFLF and 18 F-fluorodeoxyglucose (FDG) were administered to mice with or without T2DM. Diabetic mice showed an increased 18 FDG uptake in the subcutaneous fat compared with control mice, but pancreatic uptake was minimal for either group. In contrast, diabetic mice exhibited visually noticeable more cFLFLF- 64 Cu retention in pancreas and liver than control mice. The heart and pancreas isolated from diabetic mice contained more macrophages and showed stronger PET signals than those of control mice. Flow cytometry analysis revealed the presence of macrophages but not neutrophils in pancreatic islets. Real-time PCR analysis revealed much higher FPR1 expression in pancreatic islets of diabetic over control mice. Autoradiography and immunohistochemical analysis confirmed abundant FPR1 expression in atherosclerotic lesions. Thus, 64 Cu-labeled cFLFLF peptide is a more effective PET agent for detecting macrophages compared to FDG

  14. Targeting CXCR4 by a selective peptide antagonist modulates tumor microenvironment and microglia reactivity in a human glioblastoma model.

    Science.gov (United States)

    Mercurio, Laura; Ajmone-Cat, Maria Antonietta; Cecchetti, Serena; Ricci, Alessandro; Bozzuto, Giuseppina; Molinari, Agnese; Manni, Isabella; Pollo, Bianca; Scala, Stefania; Carpinelli, Giulia; Minghetti, Luisa

    2016-03-25

    The CXCL12/CXCR4 pathway regulates tumor cell proliferation, metastasis, angiogenesis and the tumor-microenvironment cross-talk in several solid tumors, including glioblastoma (GBM), the most common and fatal brain cancer. In the present study, we evaluated the effects of peptide R, a new specific CXCR4 antagonist that we recently developed by a ligand-based approach, in an in vitro and in vivo model of GBM. The well-characterized CXCR4 antagonist Plerixafor was also included in the study. The effects of peptide R on CXCR4 expression, cell survival and migration were assessed on the human glioblastoma cell line U87MG exposed to CXCL12, by immunofluorescence and western blotting, MTT assay, flow cytometry and transwell chamber migration assay. Peptide R was then tested in vivo, by using U87MG intracranial xenografts in CD1 nude mice. Peptide R was administered for 23 days since cell implantation and tumor volume was assessed by magnetic resonance imaging (MRI) at 4.7 T. Glioma associated microglia/macrophage (GAMs) polarization (anti-tumor M1 versus pro-tumor M2 phenotypes) and expressions of vascular endothelial growth factor (VEGF) and CD31 were assessed by immunohistochemistry and immunofluorescence. We found that peptide R impairs the metabolic activity and cell proliferation of human U87MG cells and stably reduces CXCR4 expression and cell migration in response to CXCL12 in vitro. In the orthotopic U87MG model, peptide R reduced tumor cellularity, promoted M1 features of GAMs and astrogliosis, and hindered intra-tumor vasculature. Our findings suggest that targeting CXCR4 by peptide R might represent a novel therapeutic approach against GBM, and contribute to the rationale to further explore in more complex pre-clinical settings the therapeutic potential of peptide R, alone or in combination with standard therapies of GBM.

  15. Cyclosporin H, Boc-MLF and Boc-FLFLF are antagonists that preferentially inhibit activity triggered through the formyl peptide receptor.

    Science.gov (United States)

    Stenfeldt, Anna-Lena; Karlsson, Jennie; Wennerås, Christine; Bylund, Johan; Fu, Huamei; Dahlgren, Claes

    2007-12-01

    In order to properly interpret receptor inhibition experiments, the precise receptor specificities of the employed antagonists are of crucial importance. Lately, a great number of agonists for various formyl peptide receptors have been identified using a selection of antagonists. However, some confusion exists as to the precise receptor specificities of many of these antagonists. We have investigated the effects of formyl peptide receptor family antagonists on the neutrophil response induced by agonists for the formyl peptide receptor (FPR) and the formyl peptide receptor like 1 (FPRL1). To determine FPR- and FPRL1-specific interactions, these antagonists should not be used at used at concentrations above 10 microM. Signaling through FPR was inhibited by low concentrations of the antagonists cyclosporin H, Boc-MLF (also termed Boc-1), and Boc-FLFLFL (also termed Boc-2), while higher concentrations also partly inhibited the signaling through FPRL1. The antagonist WRWWWW (WRW(4)) specifically inhibited the signaling through FPRL1 at low concentrations but at high concentrations also partly the signaling through FPR. Based on the difference in potency of cyclosporin H and the two Boc-peptides, we suggest using cyclosporin H as a specific inhibitor for FPR. To specifically inhibit the FPRL1 response the antagonist WRW(4) should be used.

  16. A Gly/Ala switch contributes to high affinity binding of benzoxazinone-based non-peptide oxytocin receptor antagonists.

    Science.gov (United States)

    Hawtin, Stuart R; Ha, Sookhee N; Pettibone, Douglas J; Wheatley, Mark

    2005-01-17

    Non-peptide antagonists of the oxytocin receptor (OTR) have been developed to prevent pre-term labour. The benzoxazinone-based antagonists L-371,257 and L-372,662 display pronounced species-dependent pharmacology with respect to selectivity for the OTR over the V(1a) vasopressin receptor. Examination of receptor sequences from different species identified Ala(318) in helix 7 of the human OTR as a candidate discriminator required for high affinity binding. The mutant receptor [A318G]OTR was engineered and characterised using ligands representing many different chemical classes. Of all the ligands investigated, only the benzoxazinone-based antagonists had decreased affinity for [A318G]OTR. Molecular modelling revealed that Ala(318) provides a direct hydrophobic contact with a methoxy group of L-371,257 and L-372,662.

  17. CGRP receptors mediating CGRP-, adrenomedullin- and amylin-induced relaxation in porcine coronary arteries. Characterization with 'Compound 1' (WO98/11128), a non-peptide antagonist

    DEFF Research Database (Denmark)

    Hasbak, P; Sams, A; Schifter, S

    2001-01-01

    . The partial porcine mRNA sequences shared 82 - 92% nucleotide identity with human sequences. 3. The human peptides alphaCGRP, betaCGRP, AM and amylin induced relaxation with pEC(50) values of 8.1, 8.1, 6.7 and 6.1 M respectively. 4. The antagonistic properties of a novel non-peptide CGRP antagonist 'Compound...

  18. Identification of Peptidic Antagonists of Vascular Endothelial Growth Factor Receptor 1 by Scanning the Binding Epitopes of Its Ligands.

    Science.gov (United States)

    Wang, Lei; Zhou, Lingyu; Reille-Seroussi, Marie; Gagey-Eilstein, Nathalie; Broussy, Sylvain; Zhang, Tianyu; Ji, Lili; Vidal, Michel; Liu, Wang-Qing

    2017-08-10

    Cancer angiogenesis is mainly initiated by vascular endothelial growth factors (VEGFs). On the basis of the reported crystal structures of three natural ligands (VEGF-A, -B, and PlGF) with the major receptors VEGFR-1 and VEGFR-2, we scanned receptor-binding epitopes of these ligands by designing linear and cyclic peptides with the aim to disrupt the VEGF-A/VEGFR-1 interaction, which is implicated in cancer development. The ability of peptides to inhibit this interaction was evaluated by an ELISA-based assay. Several peptides, especially those mimicking loop 1 (L1) of these ligands that binds primarily to domain D3 of VEGFRs, have demonstrated higher inhibition for VEGF-A/VEGFR-1 binding. They have also shown inhibitory effects on VEGF-induced tube formation in HUVECs (human umbilical vein endothelial cells). These results validate the domain D3 of VEGFRs as an efficient target for the design of VEGFR antagonists.

  19. Screening a Phage Display Library for Two Novel OmpU-Binding Peptides with Adhesion Antagonistic Activity against Vibrio mimicus.

    Directory of Open Access Journals (Sweden)

    Lifang Qi

    Full Text Available Vibrio mimicus is a pathogen that causes ascites disease in fish. We have previously demonstrated that the outer membrane protein U (OmpU is an important adhesin in V. mimicus. Here eight specific OmpU-binding phage clones, which presented three different OmpU-binding peptides (designated P1, P2, P3, were screened from a commercially available phage displayed 12-mer peptide library using rOmpU protein as target. Then, synthetic OmpU-binding peptides were measured for their adhesion antagonistic activity and binding affinity via adhesion inhibition test and non-competitive ELISA, respectively. The results showed that after co-incubated with the mixture of rOmpU and P3, visible green fluorescence could be observed on the epithelioma papulosum cyprinidi (EPC cells surface; while the EPC cells co-incubated with the mixture of rOmpU and P1/P2 exhibited little green fluorescence. The average adhesion number of V. mimicus 04-14 isolate before and after treatment with peptide was 21.4 ± 1.5, 20.8 ± 0.8 (irrelevant peptide, 20.2 ± 0.5 (P3, 5.1 ± 0.7 (P1 and 3.4 ± 0.8 (P2, respectively. There was a significant decrease in the adhesive level of 04-14 isolate treated with P1/ P2 compared to the untreated isolate (p<0.01. The affinity constants of P1 and P2 were (6.17 ± 0.19 × 108 L/mol and (1.24 ± 0.56 × 109 L/mol, respectively. Furthermore, protective effects of P1 and P2 on grass carps challenged with V. mimicus were preliminary detected. It was found there was delayed death of fish in the groups treated with P1/P2, and the survival rate of challenged fish improved with the increase of the dose of adhesion antagonistic peptide. Taken together, two novel OmpU-binding peptides, which possessed adhesion antagonistic activity, high affinity and a certain degree of antibacterial activity against V. mimicus, were screened and identified.

  20. Screening a Phage Display Library for Two Novel OmpU-Binding Peptides with Adhesion Antagonistic Activity against Vibrio mimicus.

    Science.gov (United States)

    Qi, Lifang; Liu, Yan; Tao, Huizhu; Xiao, Ning; Li, Jinnian; Kong, Lingyan; Hou, Liting

    2016-01-01

    Vibrio mimicus is a pathogen that causes ascites disease in fish. We have previously demonstrated that the outer membrane protein U (OmpU) is an important adhesin in V. mimicus. Here eight specific OmpU-binding phage clones, which presented three different OmpU-binding peptides (designated P1, P2, P3), were screened from a commercially available phage displayed 12-mer peptide library using rOmpU protein as target. Then, synthetic OmpU-binding peptides were measured for their adhesion antagonistic activity and binding affinity via adhesion inhibition test and non-competitive ELISA, respectively. The results showed that after co-incubated with the mixture of rOmpU and P3, visible green fluorescence could be observed on the epithelioma papulosum cyprinidi (EPC) cells surface; while the EPC cells co-incubated with the mixture of rOmpU and P1/P2 exhibited little green fluorescence. The average adhesion number of V. mimicus 04-14 isolate before and after treatment with peptide was 21.4 ± 1.5, 20.8 ± 0.8 (irrelevant peptide), 20.2 ± 0.5 (P3), 5.1 ± 0.7 (P1) and 3.4 ± 0.8 (P2), respectively. There was a significant decrease in the adhesive level of 04-14 isolate treated with P1/ P2 compared to the untreated isolate (p<0.01). The affinity constants of P1 and P2 were (6.17 ± 0.19) × 108 L/mol and (1.24 ± 0.56) × 109 L/mol, respectively. Furthermore, protective effects of P1 and P2 on grass carps challenged with V. mimicus were preliminary detected. It was found there was delayed death of fish in the groups treated with P1/P2, and the survival rate of challenged fish improved with the increase of the dose of adhesion antagonistic peptide. Taken together, two novel OmpU-binding peptides, which possessed adhesion antagonistic activity, high affinity and a certain degree of antibacterial activity against V. mimicus, were screened and identified.

  1. A novel antagonistic role of natural compound icariin on neurotoxicity of amyloid β peptide

    Directory of Open Access Journals (Sweden)

    Jianhui Liu

    2015-01-01

    Interpretation & conclusions: The results indicated a novel antagonistic role of icariin in the neurotoxicity of Aβ1-42 via inhibiting its aggregation, suggesting that icariin might have potential therapeutic benefits to delay or modify the progression of AD.

  2. Antiviral activity of formyl peptide receptor 2 antagonists against influenza viruses.

    Science.gov (United States)

    Courtin, Noémie; Fotso, Aurélien Fotso; Fautrad, Pierre; Mas, Floriane; Alessi, Marie-Christine; Riteau, Béatrice

    2017-07-01

    Influenza viruses are one of the most important respiratory pathogens worldwide, causing both epidemic and pandemic infections. The aim of the study was to evaluate the effect of FPR2 antagonists PBP10 and BOC2 on influenza virus replication. We determined that these molecules exhibit antiviral effects against influenza A (H1N1, H3N2, H6N2) and B viruses. FPR2 antagonists used in combination with oseltamivir showed additive antiviral effects. Mechanistically, the antiviral effect of PBP10 and BOC2 is mediated through early inhibition of virus-induced ERK activation. Finally, our preclinical studies showed that FPR2 antagonists protected mice from lethal infections induced by influenza, both in a prophylactic and therapeutic manner. Thus, FPR2 antagonists might be explored for novel treatments against influenza. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Retinoic acid receptor gamma impacts cellular adhesion, Alpha5Beta1 integrin expression and proliferation in K562 cells.

    Science.gov (United States)

    Kelley, Melissa D; Phomakay, Raynin; Lee, Madison; Niedzwiedz, Victoria; Mayo, Rachel

    2017-01-01

    The interplay between cellular adhesion and proliferation is complex; however, integrins, particularly the α5β1 subset, play a pivotal role in orchestrating critical cellular signals that culminate in cellular adhesion and growth. Retinoids modify the expression of a variety of adhesive/proliferative signaling proteins including α5β1 integrins; however, the role of specific retinoic acid receptors involved in these processes has not been elucidated. In this study, the effect of all-trans-retinoic acid receptor (RAR) agonists on K562 cellular adhesion, proliferation, and α5β1 integrin cell surface expression was investigated. RARγ agonist exposure increased K562 cellular adhesion to RGD containing extracellular matrix proteins fibronectin and FN-120 in a time- and concentration dependent manner, while RARα or RARβ agonist treatment had no effect on cellular adhesion. Due to the novel RARγ- dependent cellular adhesion response exhibited by K562 cells, we examined α5 and β1 integrin subunit expression when K562 cells were exposed to retinoid agonists or vehicle for 24, 48, 72 or 96 hours. Our data demonstrates no differences in K562 cell surface expression of the α5 integrin subunit when cells were exposed to RARα, RARβ, or RARγ agonists for all time points tested. In contrast, RARγ agonist exposure resulted in an increase in cell surface β1 integrin subunit expression within 48 hours that was sustained at 72 and 96 hours. Finally, we demonstrate that while exposure to RARα or RARβ agonists have no effect on K562 cellular proliferation, the RARγ agonist significantly dampens K562 cellular proliferation levels in a time- and concentration- dependent manner. Our study is the first to report that treatment with a RARγ specific agonist augments cellular adhesion to α5β1 integrin substrates, increases cell surface levels of the β1 integrin subunit, and dampens cellular proliferation in a time and concentration dependent manner in a human erythroleukemia cell line.

  4. Fibronectin-binding protein acts as Staphylococcus aureus invasin via fibronectin bridging to integrin alpha5beta1

    NARCIS (Netherlands)

    Sinha, B; François, P P; Nüsse, O; Foti, M; Hartford, O M; Vaudaux, P; Foster, T J; Lew, D P; Herrmann, M; Krause, K H

    The ability of Staphylococcus aureus to invade mammalian cells may explain its capacity to colonize mucosa and to persist in tissues after bacteraemia. To date, the underlying molecular mechanisms of cellular invasion by S. aureus are unknown, despite its high prevalence and difficulties in

  5. A SOCS1/3 antagonist peptide protects mice against lethal infection with influenza A virus

    Directory of Open Access Journals (Sweden)

    Chulbul M. Ahmed

    2015-11-01

    Full Text Available We have developed an antagonist to suppressor of cytokine signaling 1 (SOCS1, pJAK2(1001-1013, that corresponds to the activation loop of the Janus kinase JAK2, which is the binding site for the kinase inhibitory region (KIR of SOCS1. Internalized pJAK2(1001-1013 inhibits SOCS1 and SOCS3. SOCS1 has been shown to be an influenza virus induced virulence factor that enhances infection of cells. The antagonist was protective in cell culture and in influenza virus PR8 lethally infected C57BL/6 mice. The SOCS antagonist also prevented adverse morbidity as assessed by parameters such as weight loss and drop in body temperature and showed potent induction of both the cellular and humoral immune responses to the influenza virus candidate universal antigen matrix protein 2 (M2e. The SOCS antagonist thus protected mice against lethal influenza virus infection and possessed potent adjuvancy against the M2e candidate influenza virus universal vaccine antigen.

  6. Development of potent antagonists for formyl peptide receptor 1 based on Boc-Phe-D-Leu-Phe-D-Leu-Phe-OH.

    Science.gov (United States)

    Hayashi, Ryo; Kitajima, Toshiki; Mizuguchi, Hikaru; Fujimoto, Miki; Yamaguchi, Aya; Koga, Shuichiro; Koga, Yuya; Osada, Satoshi; Kodama, Hiroaki

    2014-08-01

    While stimulation of formyl peptide receptors (FPRs) on the surface of human neutrophils induces several immune responses, under conditions of continuous activation of the receptor by agonists such as formyl-Met-Leu-Phe-OH (fMLP), neutrophil-dependent tissue damage ensues. Thus, FPR antagonists could be anticipated as drugs for FPR-related disease. In this study, Boc-Phe-D-Leu-Phe-D-Leu-Phe-OH (Boc-FlFlF), one of several FPR subtype selective antagonists, was chosen and the positions at the Phe residues were optimized. We found that substitution with unnatural amino acids resulted in an improvement of two orders of magnitude. The most potent antagonist indicated FPR subtype selectivity at 1 μM. In addition to finding a potent antagonist, the structure-activity trends observed in this study should be valuable in designing a new type of FPR subtype selective antagonist. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Investigation of CGRP receptors and peptide pharmacology in human coronary arteries. Characterization with a nonpeptide antagonist

    DEFF Research Database (Denmark)

    Hasbak, Philip; Saetrum Opgaard, Ole; Eskesen, Karen

    2003-01-01

    . Preincubation with alphaCGRP(8-37) (10(-6) M) and Compound 1 (10(-6) M) caused significant rightward shift of the concentration-response curves for AM and amylin as well with pK B values between 6.6 and 7.5. Preincubation with AM(22-52) had no antagonistic effect on the AM and amylin response, neither did...

  8. Development of Peptide Antagonists of Chemokine Receptors Involved in Breast Cancer Metastasis

    National Research Council Canada - National Science Library

    Blondelle, Sylvie E

    2004-01-01

    .... This was accomplished by screening in a competitive assay synthetic combinatorial libraries (SCLs) made up of D-amino acid peptides for their ability to antagonize CXCR4 receptor function using HeLa cells and PBMC cells (used as standard...

  9. Development of Peptide Antagonists of Chemokine Receptors Involved in Breast Cancer Metastasis

    National Research Council Canada - National Science Library

    Blondelle, Sylvie E

    2005-01-01

    .... This was accomplished by screening in a competitive assay synthetic combinatorial libraries (SCLs) made up of D-amino acid peptides for their ability to antagonize CXCR4 receptor function using HeLa cells and PBMC cells (used as standard...

  10. Effects of thrombin, PAR-1 activating peptide and a PAR-1 antagonist on umbilical artery resistance in vitro

    Directory of Open Access Journals (Sweden)

    Elliott John T

    2005-02-01

    Full Text Available Abstract Background The non-thrombotic effects of thrombin in cardiovascular tissues, as mediated via the protease activated receptors (PARs, and particularly PAR-1, have been the focus of much recent research. The aims of this study were to evaluate the effects of thrombin, a specific PAR-1 activating peptide (PAR1-AP, and a PAR-1 antagonist on human umbilical artery tone in vitro. Methods Human umbilical artery samples were obtained from 17 women at term. Arterial rings were suspended under physiologic conditions for isometric recording. The in vitro effects of thrombin (0.5 units/mL to 3 units/mL, PAR1-AP TFLLR-NH2 [10(-9 to 10(-6 M], and PAR-1 antagonist (N-trans cinnamoyl- p-fluoroPhe-p-guanidinoPhe-Leu-Arg-Orn-NH2 [10(-9 M to 10(-5 M] on umbilical artery tone were measured. Results Both thrombin and TFLLR-NH2 exerted a potent cumulative vasodilatory effect on human umbilical artery resistance (P 0.05. Conclusion These findings highlight a potential role for thrombin and PAR-1 receptors in vascular regulation of feto-placental blood flow in normal pregnancy, and in association with the vascular lesions associated with IUGR and pre-eclampsia.

  11. The effect of systemic PTEN antagonist peptides on axon growth and functional recovery after spinal cord injury.

    Science.gov (United States)

    Ohtake, Yosuke; Park, Dongsun; Abdul-Muneer, P M; Li, Hui; Xu, Bin; Sharma, Kartavya; Smith, George M; Selzer, Michael E; Li, Shuxin

    2014-05-01

    Knockout studies suggest that PTEN limits the regenerative capacities of CNS axons as a dominant antagonist of PI3 kinase, but the transgenic approach is not feasible for treating patients. Although application of bisperoxovanadium may block PTEN function, it is a general inhibitor of phosphotyrosine phosphatases and may target enzymes other than PTEN, causing side effects and preventing firm conclusions about PTEN inhibition on regulating neuronal growth. A pharmacological method to selectively suppress PTEN post-injury could be a valuable strategy for promoting CNS axon regeneration. We identified PTEN antagonist peptides (PAPs) by targeting PTEN critical functional domains and evaluated their efficacy for promoting axon growth. Four PAPs (PAP 1-4) bound to PTEN protein expressed in COS7 cells and blocked PTEN signaling in vivo. Subcutaneous administration of PAPs initiated two days after dorsal over-hemisection injury significantly stimulated growth of descending serotonergic fibers in the caudal spinal cord of adult mice. Systemic PAPs induce significant sprouting of corticospinal fibers in the rostral spinal cord and limited growth of corticospinal axons in the caudal spinal cord. More importantly, PAP treatment enhanced recovery of locomotor function in adult rodents with spinal cord injury. This study may facilitate development of effective therapeutic agents for CNS injuries. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. A peptide antagonist of ErbB receptors, Inherbin3, induces neurite outgrowth from rat cerebellar granule neurons through ErbB1 inhibition

    DEFF Research Database (Denmark)

    Xu, Ruodan; Pankratova, Stanislava; Christiansen, Søren Hofman

    2013-01-01

    ErbB receptors not only function in cancer, but are also key developmental regulators in the nervous system. We previously identified an ErbB1 peptide antagonist, Inherbin3, that is capable of inhibiting tumor growth in vitro and in vivo. In this study, we found that inhibition of ErbB1 kinase...

  13. Antagonistic interactions and production of halocin antimicrobial peptides among extremely halophilic prokaryotes isolated from the solar saltern of Sfax, Tunisia.

    Science.gov (United States)

    Ghanmi, Fadoua; Carré-Mlouka, Alyssa; Vandervennet, Manon; Boujelben, Ines; Frikha, Doniez; Ayadi, Habib; Peduzzi, Jean; Rebuffat, Sylvie; Maalej, Sami

    2016-05-01

    Thirty-five extremely halophilic microbial strains isolated from crystallizer (TS18) and non-crystallizer (M1) ponds in the Sfax solar saltern in Tunisia were examined for their ability to exert antimicrobial activity. Antagonistic assays resulted in the selection of eleven strains that displayed such antimicrobial activity and they were further characterized. Three cases of cross-domain inhibition (archaea/bacteria or bacteria/archaea) were observed. Four archaeal strains exerted antimicrobial activity against several other strains. Three strains, for which several lines of evidence suggested the antimicrobial activity was, at least in part, due to peptide/protein agents (Halobacterium salinarum ETD5, Hbt. salinarum ETD8, and Haloterrigena thermotolerans SS1R12), were studied further. Optimal culture conditions for growth and antimicrobial production were determined. Using DNA amplification with specific primers, sequencing and RT-PCR analysis, Hbt. salinarum ETD5 and Hbt. salinarum ETD8 were shown to encode and express halocin S8, a hydrophobic antimicrobial peptide targeting halophilic archaea. Although the gene encoding halocin H4 was amplified from the genome of Htg. thermotolerans SS1R12, no transcript could be detected and the antimicrobial activity was most likely due to multiple antimicrobial compounds. This is also the first report that points to four different strains isolated from different geographical locations with the capacity to produce identical halocin S8 proteins.

  14. Antagonistic Activities of Novel Peptides from Bacillus amyloliquefaciens PT14 against Fusarium solani and Fusarium oxysporum.

    Science.gov (United States)

    Kim, Young Gwon; Kang, Hee Kyoung; Kwon, Kee-Deok; Seo, Chang Ho; Lee, Hyang Burm; Park, Yoonkyung

    2015-12-09

    Bacillus species have recently drawn attention due to their potential use in the biological control of fungal diseases. This paper reports on the antifungal activity of novel peptides isolated from Bacillus amyloliquefaciens PT14. Reverse-phase high-performance liquid chromatography revealed that B. amyloliquefaciens PT14 produces five peptides (PT14-1, -2, -3, -4a, and -4b) that exhibit antifungal activity but are inactive against bacterial strains. In particular, PT14-3 and PT14-4a showed broad-spectrum antifungal activity against Fusarium solani and Fusarium oxysporum. The PT14-4a N-terminal amino acid sequence was identified through Edman degradation, and a BLAST homology analysis showed it not to be identical to any other protein or peptide. PT14-4a displayed strong fungicidal activity with minimal inhibitory concentrations of 3.12 mg/L (F. solani) and 6.25 mg/L (F. oxysporum), inducing severe morphological deformation in the conidia and hyphae. On the other hand, PT14-4a had no detectable hemolytic activity. This suggests PT14-4a has the potential to serve as an antifungal agent in clinical therapeutic and crop-protection applications.

  15. Potent anti-tumor effect generated by a novel human papillomavirus (HPV antagonist peptide reactivating the pRb/E2F pathway.

    Directory of Open Access Journals (Sweden)

    Cai-ping Guo

    Full Text Available Human papillomavirus type 16 (HPV16 E7 is a viral oncoprotein believed to play a major role in cervical cancer. In this study, an antagonist peptide against HPV16E7 protein was first identified from screening the c7c phage display peptide library. The binding specificity and affinity of the selected peptide to HPV16E7 were tested by competitive enzyme-linked immunosorbent assay (ELISA. The antagonist peptide showed obvious anti-tumor efficacy both in cell lines and animal tumor models. Significant cell proliferation inhibition with high specificity was noted when HPV16-positive cells were treated with the peptide. This anti-tumor efficacy was resulted from overriding the activities of HPV16E7 and reactivating the pRb/E2F pathway, as shown by a series of experiments. Flow cytometry analysis revealed that the selected peptide induced G1 arrest in a dose-dependent manner. Competitive ELISA, pull down, and Co-IP experiments indicated that the selected peptide disrupted the interaction between HPV16E7 and pRb proteins both in vitro and in vivo. Luciferase reporter assay verified that transcription activities of E2F were suppressed by the peptide through restoration of pRb. RT-PCR and Western blot revealed that it reduced cyclins A, D1, and E1 expression, and led to HPV16E7 protein degradation, but pRb protein stabilization. The current study suggests that this specific peptide may serve as a potential therapeutic agent for HPV16-positive cervical cancer.

  16. Synthesis and characterization of a selective peptide antagonist of neuropeptide Y vascular postsynaptic receptors.

    Science.gov (United States)

    Lew, M. J.; Murphy, R.; Angus, J. A.

    1996-01-01

    1. A cyclic dimeric nonapeptide neuropeptide Y (NPY) receptor antagonist, 1229U91, was synthesized by Fmoc chemistry and dimerised in solution. Its effects were assayed in mesenteric arteries from rats and mice, and in rat vas deferens. 2. Mesenteric arteries were cannulated and pressurised to 55 mmHg and the external diameters continuously measured. NPY, PYY, Leu31Pro34NPY and NPY(13-36) each caused concentration-related contractions with the order of potency PYY > or = Leu31Pro34NPY = NPY > NPY (13-36), consistent with the Y1 receptor subtype. 3. 1229U91 had no agonist activity in the arteries but caused a concentration-related rightward shift of NPY (mouse arteries) or Leu31Pro34NPY (rat) concentration-response curves. The antagonism was competitive with pKBS of 7.69 +/- 0.15 and 7.47 +/- 0.13 in the mouse and rat arteries, respectively. 4. Sympathetic nerves in the vas deferens were stimulated with a single electrical field pulse every 20 s and the twitch responses recorded. NPY, PYY, Leu31Pro34NPY and NPY(13-36) inhibited the twitches with the order of potency PYY > NPY > NPY(13-36) >> Leu31Pro34NPY, consistent with the Y2 receptor subtype. 5. 1229U91 inhibited the vas deferens twitch with a shallow concentration-response curve and a time-course of inhibition distinct from that of NPY. 1229U91 (30 microM) did not cause a rightward shift of the NPY concentration-response curve. 1229U91 is at least 5 orders of magnitude less potent in the vas deferens than in rat brain Y2 binding assays reported by others, suggesting that the brain and vas deferens Y2 receptors are different. 6. It is concluded that 1229U91 is a competitive antagonist of NPY Y1 vascular receptors and has additional properties that inhibit the electrically evoked twitch of the rat vas deferens. PMID:8732289

  17. PC1, a non-peptide PKR1-preferring antagonist, reduces pain behavior and spinal neuronal sensitization in neuropathic mice.

    Science.gov (United States)

    Guida, F; Lattanzi, R; Boccella, S; Maftei, D; Romano, R; Marconi, V; Balboni, G; Salvadori, S; Scafuro, M A; de Novellis, V; Negri, L; Maione, S; Luongo, L

    2015-01-01

    Peripheral neuropathy is characterized by abnormal pain responses triggered by the release of several mediators and neuronal hyperexcitability at the spinal cord level. Emerging evidence indicates that the enhanced activity of dorsal horn neurons requires communication with glia and microglia, cells that are physiologically involved in neuronal wellbeing. Prokineticins (PKs), which include PK1 and PK2, represent a novel family of chemokines characterized by a unique structural motif comprising five disulfide bonds. They are expressed in the peripheral and central nervous system. PKs bind two G protein coupled receptors, PKR1 and PKR2, and participate in the regulation of several biological processes, including pain sensation. This study aimed to investigate the anti-nociceptive effect of PC1, a non-peptide PKR1-preferring antagonist, in a mouse model of neuropathic pain. To do this, we assessed the activity of spinal cord nociceptive neurons as well as astrocyte and microglia phenotypes after repeated administration of PC1 in vivo. PC1 treatment strongly delayed the development of thermal hyperalgesia and tactile and mechanical allodynia. It also reduced spinal microglial and glial activation 8 days post injury in spared nerve injury (SNI) mice. Neuropathic mice showed an increased level of PK2 protein in the spinal cord, mostly in astrocytes. PC1 treatment completely reversed the increased responsiveness to mechanical stimuli, the decreased threshold of neuronal activation, and the increased spontaneous activity that were observed in nociceptive specific (NS) neurons of SNI mice. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    E. Fok

    2015-01-01

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

  19. Exendin-3, a novel peptide from Heloderma horridum venom, interacts with vasoactive intestinal peptide receptors and a newly described receptor on dispersed acini from guinea pig pancreas. Description of exendin-3(9-39) amide, a specific exendin receptor antagonist.

    Science.gov (United States)

    Raufman, J P; Singh, L; Eng, J

    1991-02-15

    Exendin-3 increased cellular cAMP levels and amylase release from dispersed acini from guinea pig pancreas. Low concentrations (0.1-3 nM) caused a 12-fold increase in cAMP, whereas higher concentrations (0.3-3 microM) caused an additional 24-fold increase in cAMP. Maximal cAMP with the highest concentration tested was the same as the maximal response with secretin, vasoactive intestinal peptide (VIP), peptide histidine isoleucine, helodermin, or helospectin-I. In terms of amylase release, exendin-3 had the same efficacy but was the least potent of these peptides. Exendin-3-induced increases in amylase release were inhibited by VIP receptor antagonists and the new peptide (greater than 0.1 microM) competed with radiolabeled VIP for binding sites on dispersed acini. Increasing concentrations of an exendin-3 fragment, exendin-3(9-39) amide, did not increase cAMP or amylase release but inhibited the increase in cAMP observed with 0.1-3 nM exendin-3. The fragment did not alter the effects of other peptides that are known to increase acinar cAMP. We conclude that exendin-3 interacts with at least two receptors on guinea pig pancreatic acini; at high concentrations (greater than 100 nM) the peptide interacts with VIP receptors, thereby causing a large increase in cAMP and stimulating amylase release; at lower concentrations (0.1-3 nM) the peptide interacts with a putative exendin receptor, thereby causing a smaller increase in cAMP of undetermined function. Exendin-3(9-39) amide is a specific exendin receptor antagonist.

  20. In vitro Evaluation of a Bombesin Antagonistic Analogue Conjugated with DOTA-Ala(SO{sub 3}H)-Aminooctanoyl for Targeting of the Gastrin-releasing Peptide Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Cheong; Cho, Eun Ha; Kim, Jin Joo; Lee, So Young; Choi, Sang Mu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    As Bombesin (BBS) binds with high affinity to GRPR, BBS derivatives have been labeled with various radionuclides such as {sup 99}mTc, {sup 111}In, {sup 90}Y, {sup 64}Cu, {sup 177}Lu, {sup 68}Ga, or {sup 18}F and have proved to be successful candidates for peptide receptor radiotherapy (PRRT). In this study, we employed Ala(SO{sub 3}H)-Aminooctanoyl as a linker of BBS antagonistic peptide sequence, Gln-Trp-Ala-Val-N methyl Gly-His-Statine-Leu-NH{sub 2}, with DOTA to prepare radiolabeled candidates for GRPR targeting. A DOTA-conjugated BBS antagonistic analogue was synthesized and radiolabeled with {sup 177}Lu, and in vitro characteristics on GRPR-overexpressing human prostate tumor cells were evaluated. In conclusion, a novel BBS antagonistic analogue, {sup 177}Lu-DOTA-sBBNA, is a promising candidate for the targeting of GRPR-over-expressing tumors. Further investigations to evaluate its in vivo characteristics and therapeutic efficacy are needed.

  1. Oral delivery of oil-based formulation for a novel synthetic cationic peptide of GnRH (gonadotropin-releasing hormone) antagonist for prostate cancer treatment.

    Science.gov (United States)

    Zhang, Guiying; Wang, Tao; Gao, Lijun; Quan, Dongqin

    2013-06-25

    LXT-101, a cationic peptide is a novel antagonist of gonadotropin-releasing hormone (GnRH) for prostate cancer treatment. However, effective delivery of peptide drugs into the body by the oral route remains a major challenge due to their origin properties with high molecular weights, strong polarity and low stability in the gastrointestinal (GI) tract. In this study, we have developed a novel oral delivery of oil-based formulation in which therapeutic peptide LXT-101 are solubilized in oils and with this solution as oil phase, an optimum formulation of self-microemulsifying drug delivery system (SMEDDS) was developed. The peptide stability with the SMEDDS formulation in artificial gastric and intestinal fluid was tested in vitro. On the other hand, the testosterone level and plasma concentration of LXT-101 in rats after oral administration of the SMEDDS formulation were investigated in vivo. The data in vitro indicated that LXT-101 in the SMEDDS formulation was stable over 8 h in artificial gastric and intestinal fluid. LXT-101 can be absorbed in vivo and suppression of testosterone maintained in castration level within 12 h can be achieved effectively after SMEDDS formulation administered orally at a dose of 3.5 mg/kg. The approach can provide a potential way for delivery peptides by oral. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Solid-phase peptide synthesis of endothelin receptor antagonists on novel flexible, styrene-acryloyloxyhydroxypropyl methacrylate-tripropyleneglycol diacrylate [SAT] resin.

    Science.gov (United States)

    Siyad, M A; Nair, Arun S V; Kumar, G S Vinod

    2010-03-08

    Novel cross-linked polymeric support by the copolymerization of styrene and 3-(acryloyloxy)-2-hydroxypropyl methacrylate with Tri(propyleneglycol) diacryalte (SAT) for solid-phase peptide synthesis is presented here. The synthesis of SAT is based on the cross-linking of 3-(acryloyloxy)-2-hydroxypropyl methacrylate with styrene by free-radical suspension polymerization, consisting of an ester and a secondary hydroxyl group. An additional cross-linker tri(propyleneglycol) diacryalte provides a hydrophilic environment throughout the resin, which will enhance the physicochemical properties of the resin toward organic synthesis. The resins were synthesized in various cross-linking densities to check the swelling property, mechanical stability, and functional loading capacity. The resin was characterized by the IR, (13)C NMR, and SEM techniques. The extent of swelling properties of the polymer of different cross-linking densities were studied and compared with Merrifield resin and TentaGel. To demonstrate the efficiency of SAT support was proved by synthesizing the challenging peptide sequence of acyl carrier protein (ACP) and compared with commercially available Merrifield resin. It was further tested by synthesizing endothelial receptor antagonist peptides using SAT resin and compared with commercially available TentaGel resin. The standard Fmoc strategy was adopted for peptide synthesis and was characterized by MALDI-TOF MS and analyzed the purity of peptides by HPLC.

  3. The designer leptin antagonist peptide Allo-aca compensates for short serum half-life with very tight binding to the receptor.

    Science.gov (United States)

    Otvos, Laszlo; Vetter, Stefan W; Koladia, Mohit; Knappe, Daniel; Schmidt, Rico; Ostorhazi, Eszter; Kovalszky, Ilona; Bionda, Nina; Cudic, Predrag; Surmacz, Eva; Wade, John D; Hoffmann, Ralf

    2014-04-01

    The leptin receptor antagonist peptide Allo-aca exhibits picomolar activities in various cellular systems and sub-mg/kg subcutaneous efficacies in animal models making it a prime drug candidate and target validation tool. Here we identified the biochemical basis for its remarkable in vivo activity. Allo-aca decomposed within 30 min in pooled human serum and was undetectable beyond the same time period from mouse plasma during pharmacokinetic measurements. The C max of 8.9 μg/mL at 5 min corresponds to approximately 22% injected peptide present in the circulation. The half-life was extended to over 2 h in bovine vitreous fluid and 10 h in human tears suggesting potential efficacy in ophthalmic diseases. The peptide retained picomolar anti-proliferation activity against a chronic myeloid leukemia cell line; addition of a C-terminal biotin label increased the IC50 value by approximately 200-fold. In surface plasmon resonance assays with the biotin-labeled peptide immobilized to a NeutrAvidin-coated chip, Allo-aca exhibited exceptionally tight binding to the binding domain of the human leptin receptor with ka = 5 × 10(5) M(-1) s(-1) and kdiss = 1.5 × 10(-4) s(-1) values. Peptides excel in terms of high activity and selectivity to their targets, and may activate or inactivate receptor functions considerably longer than molecular turnovers that take place in experimental animals.

  4. Gastrin-releasing Peptide Receptor Imaging in Breast Cancer Using the Receptor Antagonist (68)Ga-RM2 And PET.

    Science.gov (United States)

    Stoykow, Christian; Erbes, Thalia; Maecke, Helmut R; Bulla, Stefan; Bartholomä, Mark; Mayer, Sebastian; Drendel, Vanessa; Bronsert, Peter; Werner, Martin; Gitsch, Gerald; Weber, Wolfgang A; Stickeler, Elmar; Meyer, Philipp T

    2016-01-01

    The gastrin-releasing peptide receptor (GRPR) is overexpressed in breast cancer. The present study evaluates GRPR imaging as a novel imaging modality in breast cancer by employing positron emission tomography (PET) and the GRPR antagonist (68)Ga-RM2. Fifteen female patients with biopsy confirmed primary breast carcinoma (3 bilateral tumors; median clinical stage IIB) underwent (68)Ga-RM2-PET/CT for pretreatment staging. In vivo tumor uptake of (68)Ga-RM2 was correlated with estrogen (ER) and progesterone (PR) receptor expression, HER2/neu status and MIB-1 proliferation index in breast core biopsy specimens. 13/18 tumors demonstrated strongly increased (68)Ga-RM2 uptake compared to normal breast tissue (defined as PET-positive). All PET-positive primary tumors were ER- and PR-positive (13/13) in contrast to only 1/5 PET-negative tumors. Mean SUVMAX of ER-positive tumors was 10.6±6.0 compared to 2.3±1.0 in ER-negative tumors (p=0.016). In a multivariate analysis including ER, PR, HER2/neu and MIB-1, only ER expression predicted (68)Ga-RM2 uptake (model: r(2) =0.55, p=0.025). Normal breast tissue showed inter- and intraindividually variable, moderate GRPR binding (SUVMAX 2.3±1.0), while physiological uptake of other organs was considerably less except pancreas. Of note, (68)Ga-RM2-PET/CT detected internal mammary lymph nodes with high (68)Ga-RM2 uptake (n=8), a contralateral axillary lymph node metastasis (verified by biopsy) and bone metastases (n=1; not detected by bone scan and CT). Our study demonstrates that (68)Ga-RM2-PET/CT is a promising imaging method in ER-positive breast cancer. In vivo GRPR binding assessed by (68)Ga-RM2-PET/CT correlated with ER expression in primary tumors of untreated patients.

  5. Solid phase synthesis of Smac/DIABLO-derived peptides using a 'Safety-Catch' resin: identification of potent XIAP BIR3 antagonists.

    Science.gov (United States)

    Elsawy, Mohamed A; Martin, Lorraine; Tikhonova, Irina G; Walker, Brian

    2013-09-01

    The N-terminal sequence of the Smac/DIABLO protein is known to be involved in binding to the BIR3 domain of the anti-apoptotic proteins IAPs, antagonizing their action. Short peptides and peptide mimetics based on the first 4-residues of Smac/DIABLO have been demonstrated to re-sensitize resistant cancer cells, over-expressing IAPs, to apoptosis. Based on the well-defined structural basis for this interaction, a small focused library of C-terminal capped Smac/DIABLO-derived peptides was designed in silico using docking to the XIAP BIR3 domain. The top-ranked computational hits were conveniently synthesized employing Solid Phase Synthesis (SPS) on an alkane sulfonamide 'Safety-Catch' resin. This novel approach afforded the rapid synthesis of the target peptide library with high flexibility for the introduction of various C-terminal amide-capping groups. The library members were obtained in high yield (>65%) and purity (>85%), upon nucleophilic release from the activated resin by treatment with various amine nucleophiles. In vitro caspase-9 activity reconstitution assays of the peptides in the presence of the recombinant BIR3-domain of human XIAP (500nM) revealed N-methylalanyl-tertiarybutylglycinyl-4-(R)-phenoxyprolyl-N-biphenylmethyl carboxamide (11a) to be the most potent XIAP BIR3 antagonist of the series synthesized inducing 93% recovery of caspase-9 activity, when used at 1μM concentration. Compound (11a) also demonstrated moderate cytotoxicity against the breast cancer cell lines MDA-MB-231 and MCF-7, compared to the Smac/DIABLO-derived wild-type peptide sequences that were totally inactive in the same cell lines. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Inhibition of growth and reduction in tumorigenicity of UCI-107 ovarian cancer by antagonists of growth hormone-releasing hormone and vasoactive intestinal peptide.

    Science.gov (United States)

    Chatzistamou, I; Schally, A V; Varga, J L; Groot, K; Armatis, P; Bajo, A M

    2001-11-01

    To evaluate the tumor inhibitory activities of antagonists of growth hormone-releasing hormone (GH-RH) and vasoactive intestinal peptide (VIP) in UCI-107 human ovarian cancer model, and to investigate the role of the insulin-like growth factor (IGF) system in the response. In the present study we investigated the effects of GH-RH antagonist JV-1-36 and VIP antagonist JV-1-52, on the growth and tumorigenicity of UCI-107 ovarian cell carcinoma xenografted into nude mice. Studies on the effects of hGH-RH(1-29)NH2, IGF-I, IGF-II, JV-1-36, and JV-1-52 on the proliferation of UCI-107 cells cultured in vitro were also performed. After 22 days of therapy with JV-1-36 or JV-1-52 at the dose of 20 microg/day, the final volume of UCI-107 tumors was significantly (PUCI-107 cells in nude mice. All ten mice injected with cells treated with medium alone developed tumors within 23 days after cell inoculation, while only eight of ten and four of ten mice injected with cells exposed to JV-1-36 or JV-1-52, respectively, had tumors. In vitro exposure of UCI-107 cells to 5-35 ng/ml IGF-II produced a significant suppression in the rate of cell proliferation (P UCI-107 ovarian cell carcinoma by mechanisms that appear to involve direct effects on the cancer cells.

  7. Introduction of a cis-prolyl mimic in position 7 of the peptide hormone oxytocin does not result in antagonistic activity.

    Science.gov (United States)

    Wittelsberger, Angela; Patiny, Luc; Slaninova, Jirina; Barberis, Claude; Mutter, Manfred

    2005-10-20

    New insights into the structure-activity relationship of the peptide hormone oxytocin are presented. Incorporation of the novel cis-prolyl mimic 2,2-dimethyl-1,3-thiazolidine-4-carboxylic acid (pseudoproline, PsiPro) at position 7 of the hormone yielded the analogue [Cys(Psi(Me,Me)pro)]7oxytocin (1) that showed a 92-95% induction of the cis peptide bond conformation between Cys6 and PsiPro7, as determined by one- and two-dimensional NMR spectra in water and in DMSO-d6. The impact of the dimethyl moiety regarding conformation and bioactivity was investigated by the synthesis of the corresponding dihydro compound, [Cys(Psi(H,H)pro)]7oxytocin (2). Biological tests of the uterotonic activity, the pressor activity, and the binding affinity to the rat and human oxytocin receptors were carried out. As a most significant result, no antagonistic activities were found for both the cis-constrained analogue 1 and analogue 2, suggesting that a cis conformation between residues 6 and 7 of the molecule does not result in antagonistic activity. However, the about 10-fold reduction in agonistic activity of 1 as compared to oxytocin is consistent with the reduction of the trans conformation from 90% for oxytocin to 5-8% for compound 1. Compound 1 retained a high binding affinity for the oxytocin receptor, with K(i) values of 8.0 and 1.9 nM for the rat and the human receptor, respectively. The correlation between the biological activities and the cis contents obtained from NMR analysis for compounds 1, 2, and oxytocin leads to the hypothesis that a cis/trans conformational change plays an important role in oxytocin receptor binding and activation.

  8. RF313, an orally bioavailable neuropeptide FF receptor antagonist, opposes effects of RF-amide-related peptide-3 and opioid-induced hyperalgesia in rodents.

    Science.gov (United States)

    Elhabazi, Khadija; Humbert, Jean-Paul; Bertin, Isabelle; Quillet, Raphaelle; Utard, Valérie; Schneider, Séverine; Schmitt, Martine; Bourguignon, Jean-Jacques; Laboureyras, Emilie; Ben Boujema, Meric; Simonnet, Guy; Ancel, Caroline; Simonneaux, Valérie; Beltramo, Massimiliano; Bucher, Bernard; Sorg, Tania; Meziane, Hamid; Schneider, Elodie; Petit-Demoulière, Benoit; Ilien, Brigitte; Bihel, Frédéric; Simonin, Frédéric

    2017-05-15

    Although opiates represent the most effective analgesics, their use in chronic treatments is associated with numerous side effects including the development of pain hypersensitivity and analgesic tolerance. We recently identified a novel orally active neuropeptide FF (NPFF) receptor antagonist, RF313, which efficiently prevents the development of fentanyl-induced hyperalgesia in rats. In this study, we investigated the properties of this compound into more details. We show that RF313 exhibited a pronounced selectivity for NPFF receptors, antagonist activity at NPFF1 receptor (NPFF1R) subtype both in vitro and in vivo and no major side effects when administered in mice up to 30 mg/kg. When co-administered with opiates in rats and mice, it improved their analgesic efficacy and prevented the development of long lasting opioid-induced hyperalgesia. Moreover, and in marked contrast with the dipeptidic NPFF receptor antagonist RF9, RF313 displayed negligible affinity and no agonist activity (up to 100 μM) toward the kisspeptin receptor. Finally, in male hamster, RF313 had no effect when administered alone but fully blocked the increase in LH induced by RFRP-3, while RF9 per se induced a significant increase in LH levels which is consistent with its ability to activate kisspeptin receptors. Altogether, our data indicate that RF313 represents an interesting compound for the development of therapeutic tools aiming at improving analgesic action of opiates and reducing adverse side effects associated with their chronic administration. Moreover, its lack of agonist activity at the kisspeptin receptor indicates that RF313 might be considered a better pharmacological tool, when compared to RF9, to examine the regulatory roles of RF-amide-related peptides and NPFF1R in reproduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. PEGylation potentiates the effectiveness of an antagonistic peptide that targets the EphB4 receptor with nanomolar affinity.

    Directory of Open Access Journals (Sweden)

    Roberta Noberini

    Full Text Available The EphB4 receptor tyrosine kinase together with its preferred ligand, ephrin-B2, regulates a variety of physiological and pathological processes, including tumor progression, pathological forms of angiogenesis, cardiomyocyte differentiation and bone remodeling. We previously reported the identification of TNYL-RAW, a 15 amino acid-long peptide that binds to the ephrin-binding pocked of EphB4 with low nanomolar affinity and inhibits ephrin-B2 binding. Although ephrin-B2 interacts promiscuously with all the EphB receptors, the TNYL-RAW peptide is remarkably selective and only binds to EphB4. Therefore, this peptide is a useful tool for studying the biological functions of EphB4 and for imaging EphB4-expressing tumors. Furthermore, TNYL-RAW could be useful for treating pathologies involving EphB4-ephrin-B2 interaction. However, the peptide has a very short half-life in cell culture and in the mouse blood circulation due to proteolytic degradation and clearance by the kidneys and reticuloendothelial system. To overcome these limitations, we have modified TNYL-RAW by fusion with the Fc portion of human IgG1, complexation with streptavidin or covalent coupling to a 40 KDa branched polyethylene glycol (PEG polymer. These modified forms of TNYL-RAW all have greatly increased stability in cell culture, while retaining high binding affinity for EphB4. Furthermore, PEGylation most effectively increases peptide half-life in vivo. Consistent with increased stability, submicromolar concentrations of PEGylated TNYL-RAW effectively impair EphB4 activation by ephrin-B2 in cultured B16 melanoma cells as well as capillary-like tube formation and capillary sprouting in co-cultures of endothelial and epicardial mesothelial cells. Therefore, PEGylated TNYL-RAW may be useful for inhibiting pathological forms of angiogenesis through a novel mechanism involving disruption of EphB4-ephrin-B2 interactions between endothelial cells and supporting perivascular mesenchymal

  10. A selective, non-peptide CRF receptor 1 antagonist prevents sodium lactate-induced acute panic-like responses.

    Science.gov (United States)

    Shekhar, Anantha; Johnson, Philip L; Fitz, Stephanie D; Nakazato, Atsuro; Chaki, Shigeyuki; Steckler, Thomas; Schmidt, Mark

    2011-04-01

    Corticotropin releasing factor (CRF) is implicated in a variety of stress-related disorders such as depression and anxiety, and blocking CRF receptors is a putative strategy for treating such disorders. Using a well-studied animal model of panic, we tested the efficacy of JNJ19567470/CRA5626, a selective, non-peptidergic CRF type 1 receptor (CRF1) antagonist (3, 10 and 40 mg/kg intraperitoneal injection), in preventing the sodium lactate (NaLac)-induced panic-like behavioural and cardiovascular responses. Adult male rats with chronic reduction of GABA levels (by inhibition of GABA synthesis with l-allyglycine, a glutamic acid decarboxylase inhibitor) in the dorsomedial/perifornical hypothalamus are highly anxious and exhibit physiological and behavioural responses to intravenous NaLac infusions similar to patients with panic disorder. These 'panic-prone' rats pre-treated with vehicle injections displayed NaLac-induced increases in autonomic responses (i.e. tachycardia and hypertensive responses), anxiety-like behaviour in the social interaction test, and flight-like increases in locomotor activity. However, systemically injecting such panic-prone rats with the highest dose of CRF1 receptor antagonist prior to NaLac infusions blocked all NaLac-induced behaviour and cardiovascular responses. These data suggest that selective CRF1 receptor antagonists could be a novel target for developing anti-panic drugs that are as effective as benzodiazepines in acute treatment of a panic attack without the deleterious side-effects (e.g. sedation and cognitive impairment) associated with benzodiazepines.

  11. Drosophila Peptide Hormones Allatostatin A and Diuretic Hormone 31 Exhibiting Complementary Gradient Distribution in Posterior Midgut Antagonistically Regulate Midgut Senescence and Adult Lifespan.

    Science.gov (United States)

    Takeda, Koji; Okumura, Takashi; Terahata, Mayu; Yamaguchi, Mio; Taniguchi, Kiichiro; Adachi-Yamada, Takashi

    2018-02-01

    Enteroendocrine cells (EEs) are evolutionarily conserved gastrointestinal secretory cells that show scattered distribution in the intestinal epithelium. These cells classified into several subtypes based on the hormones they produce in both mammals and insects. In the fruit fly Drosophila, it has been suggested that nearly equal numbers of two subtypes of EEs (Allatostatin A: AstA and Diuretic hormone 31 : Dh31) are alternately produced from the intestinal stem cells in the posterior midgut. However, we found that these two subtypes are not always present in this manner, but are rather distributed in a complementary frequency gradient along the posterior midgut. We show that midgut-preferential RNA knockdown of the peptide hormones AstA or Dh31 respectively results in decreased or increased adult lifespan. This effect on longevity is apparently correlated with the midgut senescence phenotypes as a result of direct hormone action through both hormone receptors expressed in the enteroblasts or other midgut cell types. However, gut senescence does not appear to be the direct cause for longevity regulation, as knockdown of both hormone receptors did not affect adult lifespan. Furthermore, these senescence phenotypes appear to be independent of insulin signaling and manifest in an organ-specific manner. These results indicate that the two intestinal secretory peptides antagonistically regulate adult lifespan and intestinal senescence through multiple pathways, irrespective of insulin, which implicates a complementary gradient distribution of each of the hormone-producing EEs, consistent with local requirements for cell activity along the posterior midgut.

  12. Imaging of urokinase-type plasminogen activator receptor expression using a 64Cu-labeled linear peptide antagonist by microPET

    DEFF Research Database (Denmark)

    Li, Zi-Bo; Niu, Gang; Wang, Hui

    2008-01-01

    for positron emission tomography (PET) imaging. A linear, high-affinity uPAR-binding peptide antagonist AE105 was conjugated with 1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA) and labeled with (64)Cu for microPET imaging of mice bearing U87MG human glioblastoma (uPAR positive) and MDA-MB-435...... human breast cancer (uPAR negative). RESULTS: Surface plasmon resonance measurements show that AE105 with DOTA conjugated at the alpha-amino group (DOTA-AE105) has high affinity toward uPAR. microPET imaging reveals a rapid and high accumulation of (64)Cu-DOTA-AE105 in uPAR-positive U87MG tumors (10.......8 +/- 1.5%ID/g at 4.5 hours, n = 3) but not in uPAR-negative MDA-MB-435 tumors (1.2 +/- 0.6%ID/g at 4.5 hours, n = 3). Specificity of this peptide-based imaging of uPAR was validated by further control experiments. First, a nonbinding variant of AE105 carrying a single amino acid replacement (Trp...

  13. Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site Definition and Plasma Stability

    Science.gov (United States)

    2015-11-01

    Takada, Y., X. Ye, and S. Simon , The integrins. Genome Biol, 2007. 8(5): p. 215. PMID: 17543136 3. Jia, Y., Z.Z. Zeng, S.M. Markwart, K.F. Rockwood...8099 23. Cianfrocca ME, Kimmel KA, Gallo J, Cardoso T, Brown MM, Hudes G, Lewis N, Weiner L, Lam GN, Brown SC, Shaw DE, Mazar AP, Cohen RB (2006...T, Lenhard T, Heegaard AM, Neff L, Baron R, Foged NT (2000) Proteinases in bone resorption: obvious and less obvious roles. Clinica chimica acta

  14. Integrin alpha 5 beta 1 Plays a Critical Role in Resistance to Temozolomide by Interfering with the p53 Pathway in High-Grade Glioma

    Czech Academy of Sciences Publication Activity Database

    Janoušková, Hana; Maglott, A.; Leger, D.Y.; Bossert, C.; Noulet, F.; Guerin, E.; Guenot, D.; Pinel, S.; Chastagner, P.; Plenat, F.; Entz-Werle, N.; Lehmann-Che, J.; Godet, J.; Martin, S.; Teisinger, Jan; Dontenwill, M.

    2012-01-01

    Roč. 72, č. 14 (2012), s. 3463-3470 ISSN 0008-5472 Institutional support: RVO:67985823 Keywords : cancer * integrins * high-grade glioma Subject RIV: CE - Biochemistry Impact factor: 8.650, year: 2012

  15. In Vivo Stabilization of a Gastrin-Releasing Peptide Receptor Antagonist Enhances PET Imaging and Radionuclide Therapy of Prostate Cancer in Preclinical Studies.

    Science.gov (United States)

    Chatalic, Kristell L S; Konijnenberg, Mark; Nonnekens, Julie; de Blois, Erik; Hoeben, Sander; de Ridder, Corrina; Brunel, Luc; Fehrentz, Jean-Alain; Martinez, Jean; van Gent, Dik C; Nock, Berthold A; Maina, Theodosia; van Weerden, Wytske M; de Jong, Marion

    2016-01-01

    A single tool for early detection, accurate staging, and personalized treatment of prostate cancer (PCa) would be a major breakthrough in the field of PCa. Gastrin-releasing peptide receptor (GRPR) targeting peptides are promising probes for a theranostic approach for PCa overexpressing GRPR. However, the successful application of small peptides in a theranostic approach is often hampered by their fast in vivo degradation by proteolytic enzymes, such as neutral endopeptidase (NEP). Here we show for the first time that co-injection of a NEP inhibitor (phosphoramidon (PA)) can lead to an impressive enhancement of diagnostic sensitivity and therapeutic efficacy of the theranostic (68)Ga-/(177)Lu-JMV4168 GRPR-antagonist. Co-injection of PA (300 µg) led to stabilization of (177)Lu-JMV4168 in murine peripheral blood. In PC-3 tumor-bearing mice, PA co-injection led to a two-fold increase in tumor uptake of (68)Ga-/(177)Lu-JMV4168, 1 h after injection. In positron emission tomography (PET) imaging with (68)Ga-JMV4168, PA co-injection substantially enhanced PC-3 tumor signal intensity. Radionuclide therapy with (177)Lu-JMV4168 resulted in significant regression of PC-3 tumor size. Radionuclide therapy efficacy was confirmed by production of DNA double strand breaks, decreased cell proliferation and increased apoptosis. Increased survival rates were observed in mice treated with (177)Lu-JMV4168 plus PA as compared to those without PA. This data shows that co-injection of the enzyme inhibitor PA greatly enhances the theranostic potential of GRPR-radioantagonists for future application in PCa patients.

  16. Parathyroid hormone-related peptide and the hair cycle - is it the agonists or the antagonists that cause hair growth?

    Science.gov (United States)

    Gensure, Robert C

    2014-12-01

    While the effects of PTHrP have been studied for almost 20 years, most of these studies have focused on effects on the termination of the anagen phase, giving an incomplete picture of the overall effect of PTHrP on the hair cycle. PTHrP was determined in several experimental models to promote transition of hair follicles from anagen to catagen phase, which by itself would suggest that PTHrP blockade might prolong the anagen phase and promote hair growth. However, clinical trials with topically applied PTHrP antagonists have been disappointing, leading to a reconsideration of this model. Additional studies performed in mouse models where hair follicles are damaged (alopecia areata, chemotherapy-induced alopecia) suggest that PTHrP has effects early in the hair cycle as well, promoting hair follicles' entry into anagen phase and initiates the hair cycle. While the mechanism of this has yet to be elucidated, it may involve activation of the Wnt pathway. Thus, the overall effect of PTHrP is to stimulate and accelerate the hair cycle, and in the more clinically relevant models of hair loss where hair follicles have been damaged or become quiescent, it is the agonists, not the antagonists, which would be expected to promote hair growth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Azemiopsin, a Selective Peptide Antagonist of Muscle Nicotinic Acetylcholine Receptor: Preclinical Evaluation as a Local Muscle Relaxant

    Directory of Open Access Journals (Sweden)

    Irina V. Shelukhina

    2018-01-01

    Full Text Available Azemiopsin (Az, a linear peptide from the Azemiops feae viper venom, contains no disulfide bonds, is a high-affinity and selective inhibitor of nicotinic acetylcholine receptor (nAChR of muscle type and may be considered as potentially applicable nondepolarizing muscle relaxant. In this study, we investigated its preclinical profile in regard to in vitro and in vivo efficacy, acute and chronic toxicity, pharmacokinetics, allergenic capacity, immunotoxicity and mutagenic potency. The peptide effectively inhibited (IC50 ~ 19 nM calcium response of muscle nAChR evoked by 30 μM (EC100 acetylcholine but was less potent (IC50 ~ 3 μM at α7 nAChR activated by 10 μM (EC50 acetylcholine and had a low affinity to α4β2 and α3-containing nAChR, as well as to GABAA or 5HT3 receptors. Its muscle relaxant effect was demonstrated at intramuscular injection to mice at doses of 30–300 µg/kg, 30 µg/kg being the initial effective dose and 90 µg/kg—the average effective dose. The maximal muscle relaxant effect of Az was achieved in 10 min after the administration and elimination half-life of Az in mice was calculated as 20–40 min. The longest period of Az action observed at a dose of 300 µg/kg was 55 min. The highest acute toxicity (LD50 510 μg/kg was observed at intravenous injection of Az, at intramuscular or intraperitoneal administration it was less toxic. The peptide showed practically no immunotoxic, allergenic or mutagenic capacity. Overall, the results demonstrate that Az has good drug-like properties for the application as local muscle relaxant and in its parameters, is not inferior to the relaxants currently used. However, some Az modification might be effective to extend its narrow therapeutic window, a typical characteristic and a weak point of all nondepolarizing myorelaxants.

  18. The effect of macrocyclic chelators on the targeting properties of the 68Ga-labeled gastrin releasing peptide receptor antagonist PEG2-RM26

    International Nuclear Information System (INIS)

    Varasteh, Zohreh; Mitran, Bogdan; Rosenström, Ulrika; Velikyan, Irina; Rosestedt, Maria; Lindeberg, Gunnar; Sörensen, Jens; Larhed, Mats; Tolmachev, Vladimir; Orlova, Anna

    2015-01-01

    Introduction: Overexpression of gastrin-releasing peptide receptors (GRPR) has been reported in several cancers. Bombesin (BN) analogs are short peptides with a high affinity for GRPR. Different BN analogs were evaluated for radionuclide imaging and therapy of GRPR-expressing tumors. We have previously investigated an antagonistic analog of BN (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH 2 , RM26) conjugated to NOTA via a PEG 2 spacer (NOTA-PEG 2 -RM26) labeled with 68 Ga, 111 In and Al 18 F. 68 Ga-labeled NOTA-PEG 2 -RM26 showed high tumor-to-organ ratios. Methods: The influence of different macrocyclic chelators (NOTA, NODAGA, DOTA and DOTAGA) on the targeting properties of 68 Ga-labeled PEG 2 -RM26 was studied in vitro and in vivo. Results: All conjugates were labeled with generator-produced 68 Ga with high yields and demonstrated high stability and specific binding to GRPR. The IC 50 values of nat Ga-X-PEG 2 -RM26 (X = NOTA, DOTA, NODAGA, DOTAGA) were 2.3 ± 0.2, 3.0 ± 0.3, 2.9 ± 0.3 and 10.0 ± 0.6 nM, respectively. The internalization of the conjugates by PC-3 cells was low. However, the DOTA-conjugated analog demonstrated a higher internalization rate compared to other analogs. GRPR-specific uptake was found in receptor-positive normal tissues and PC-3 xenografts for all conjugates. The biodistribution of the conjugates was influenced by the choice of the chelator moiety. Although all radiotracers cleared rapidly from the blood, [ 68 Ga]Ga-NOTA-PEG 2 -RM26 showed significantly lower uptake in lung, muscle and bone compared to the other analogs. The uptake in tumors (5.40 ± 1.04 %ID/g at 2 h p.i.) and the tumor-to-organ ratios (25 ± 3, 157 ± 23 and 39 ± 4 for blood, muscle and bone, respectively) were significantly higher for the NOTA-conjugate than the other analogs. Conclusions: Chelators had a clear influence on the biodistribution and targeting properties of 68 Ga-labeled antagonistic BN analogs. Positively charged [ 68 Ga]Ga-NOTA-PEG 2 -RM26 provided

  19. Effect of a gastrin-releasing peptide receptor antagonist and a proton pump inhibitor association in an animal model of gastritis.

    Science.gov (United States)

    Petronilho, Fabricia; Araújo, João H; Steckert, Amanda V; Rezin, Gislaine T; Ferreira, Gabriela K; Roesler, Rafael; Schwartsmann, Gilberto; Dal-Pizzol, Felipe; Streck, Emilio L

    2009-08-01

    It has been proposed that reactive oxygen species play a causative role of gastric mucosal damage induced by increased gastric secretion. Gastrin-releasing peptide is a typical neuropeptide that stimulates acid secretion by release of gastrin. In the present work we have investigated the mechanism of indomethacin (IDM)-induced gastric ulcer caused by ROS and determined the effects of a selective gastrin-releasing peptide receptor antagonist, RC-3095, alone and in association with omeprazole (OM) and compared it with an established antioxidant compound N-acetyl cysteine (NAC). Adult male Wistar rats were pre-treated for 7 days with OM, RC-3095, NAC, both drugs and water (control). The animals were then submitted to fasting for 24h; IDM was administered. Rats were killed 6h after that and the stomachs were used for evaluation of macroscopic damage and oxidative stress parameters. Our results showed that IDM increased mitochondrial superoxide production; OM and RC-3095 alone did not prevent such effect, but the combination of these drugs was effective. TBARS assay revealed that IDM-induced lipid peroxidation in gastric tissue and that OM and RC-3095, alone or in combination, prevented this effect with superior action that NAC. Finally, we verified that IDM increased protein carbonyl content and that this effect was prevented RC-3095, alone or in combination with OM, being similar to standard antioxidant. The present results support the view that, besides the inhibition of acid secretion, the protective effects exerted by OM and RC-3095 against IDM-induced gastric damage can be ascribed to a reduction of gastric oxidative injury.

  20. Production and application of HMGB1 derived recombinant RAGE-antagonist peptide for anti-inflammatory therapy in acute lung injury.

    Science.gov (United States)

    Lee, Seonyeong; Piao, Chunxian; Kim, Gyeungyun; Kim, Ji Yeon; Choi, Eunji; Lee, Minhyung

    2018-03-01

    Acute lung injury (ALI) is an inflammatory lung disease caused by sepsis, infection, or ischemia-reperfusion. The receptor for advanced glycation end-products (RAGE) signaling pathway plays an important role in ALI. In this study, a novel RAGE-antagonist peptide (RAP) was produced as an inhibitor of the RAGE signaling pathway based on the RAGE-binding domain of high mobility group box-1 (HMGB1). Recombinant RAP was over-expressed and purified using nickel-affinity chromatography. In lipopolysaccharide- or HMGB1-activated RAW264.7 macrophage cells, RAP reduced the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). RAP decreased the levels of cell surface RAGE and inhibited the nuclear translocation of nuclear factor-κB (NF-κB). These results imply that RAP decreases RAGE-mediated NF-κB activation and subsequent inflammatory reaction. For in vivo evaluation, RAP was delivered to the lungs of ALI-model animals via intratracheal administration. As a result, RAGE was down-regulated in the lung tissues by pulmonary delivery of RAP. Consequently, TNF-α, IL-6, and IL-1β were also reduced in broncoalveolar lavage fluid and the lung tissues of RAP-treated animals. Hematoxylin and eosin staining indicated that inflammation was decreased in RAP-treated animals. Collectively, these results suggest that RAP may be a useful treatment for ALI. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The non-peptide CRH1-antagonist CP-154,526 elicits a paradoxical route-dependent activation of the HPA axis.

    Science.gov (United States)

    Zaretsky, Dmitry V; Zaretskaia, Maria V; Sarkar, Sumit; Rusyniak, Daniel E; DiMicco, Joseph A

    2017-07-13

    The corticotropin-releasing hormone (CRH) plays an important role in mediating physiological response to stress and is thought to be involved in the development of various psychiatric disorders. In this paper, we compare the differences between the effect of intraperitoneal (i.p.) and intraarterial (i.a.) administration of the non-peptide CRH 1 antagonist CP-154,526 (CP) (10 and 20mg/kg) on plasma adrenocorticotropic hormone levels (ACTH), heart rate, MAP, and c-Fos expression in the paraventricular nucleus of the hypothalamus. Intraperitoneal, but not i.a., injection of CP resulted in an increase in plasma ACTH (from 105±13 to 278±51pg/ml after 20mg/kg). This effect was accompanied by a dramatic increase in c-Fos expression in cells immunoreactive for CRH in the paraventricular nucleus of the hypothalamus. When the drug was administered i.p., CP-induced activation of the HPA appears to mask the inhibitory effect of CP on stress-induced ACTH secretion, an effect which was readily apparent when the drug was given i.a. Intraperitoneal administration of CP also increased the baseline MAP which may account for previous reports that treatment with this drug attenuated the increases associated with stress. CP given by either route had no effect on baseline heart rate or stress-induced tachycardia. Thus, in all studies in which CP 154,526 is given, the route of delivery must be given careful consideration. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Molecular modeling of interactions of the non-peptide antagonist YM087 with the human vasopressin V1a, V2 receptors and with oxytocin receptors.

    Science.gov (United States)

    Giełdoń, Artur; Kaźmierkiewicz, Rajmund; Ślusarz, Rafał; Ciarkowski, Jerzy

    2001-12-01

    The nonapeptide hormones arginine vasopressin (CYFQNCPRG-NH2, AVP) and oxytocin (CYIQNCPLG-NH2, OT), control many essential functions in mammals. Their main activities include the urine concentration (via stimulation of AVP V2 receptors, V2R, in the kidneys), blood pressure regulation (via stimulation of vascular V1a AVP receptors, V1aR), ACTH control (via stimulation of V1b receptors, V1bR, in the pituitary) and labor and lactation control (via stimulation of OT receptors, OTR, in the uterus and nipples, respectively). All four receptor subtypes belong to the GTP-binding (G) protein-coupled receptor (GPCR) family. This work consists of docking of YM087, a potent non-peptide V1aR and V2R - but not OTR - antagonist, into the receptor models based on relatively new theoretical templates of rhodopsin (RD) and opiate receptors, proposed by Mosberg et al. (Univ. of Michigan, Ann Arbor, USA). It is simultaneously demonstrated that this RD template satisfactorily compares with the first historical GPCR structure of bovine rhodopsin (Palczewski et al., 2000) and that homology-modeling of V2R, V1aR and OTR using opiate receptors as templates is rational, based on relatively high (20-60%) sequence homology among the set of 4 neurophyseal and 4 opiate receptors. YM087 was computer-docked to V1aR, V2R and OTR using the AutoDock (Olson et al., Scripps Research Institute, La Jolla, USA) and subsequently relaxed using restrained simulated annealing and molecular dynamics, as implemented in AMBER program (Kollman et al., University of California, San Francisco, USA). From about 80 diverse configurations, sampled for each of the three ligand/receptor systems, 3 best energy-relaxed complexes were selected for mutual comparisons. Similar docking modes were found for the YM087/V1aR and YM087/V2R complexes, diverse from those of the YM087/OTR complexes, in agreement with the molecular affinity data.

  3. Preclinical and first clinical experience with the gastrin-releasing peptide receptor-antagonist [{sup 68}Ga]SB3 and PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Maina, Theodosia; Charalambidis, David; Nock, Berthold A. [INRASTES, NCSR ' ' Demokritos' ' , Molecular Radiopharmacy, Athens (Greece); Bergsma, Hendrik; Krenning, Eric P. [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Kulkarni, Harshad R.; Mueller, Dirk; Baum, Richard P. [Zentralklinik, Molecular Radiotherapy and Molecular Imaging, Bad Berka (Germany); Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Erasmus MC, Department of Radiology, Rotterdam (Netherlands)

    2016-05-15

    Gastrin-releasing peptide receptors (GRPR) represent attractive targets for tumor diagnosis and therapy because of their overexpression in major human cancers. Internalizing GRPR agonists were initially proposed for prolonged lesion retention, but a shift of paradigm to GRPR antagonists has recently been made. Surprisingly, radioantagonists, such as [{sup 99m}Tc]DB1 ({sup 99m}Tc-N{sub 4}'-DPhe{sup 6},Leu-NHEt{sup 13}BBN(6-13)), displayed better pharmacokinetics than radioagonists, in addition to their higher inherent biosafety. We introduce here [{sup 68}Ga]SB3, a [{sup 99m}Tc]DB1 mimic-carrying, instead of the {sup 99m}Tc-binding tetraamine, the chelator DOTA for labeling with the PET radiometal {sup 68}Ga. Competition binding assays of SB3 and [{sup nat}Ga]SB3 were conducted against [{sup 125}I-Tyr{sup 4}]BBN in PC-3 cell membranes. Blood samples collected 5 min postinjection (pi) of the [{sup 67}Ga]SB3 surrogate in mice were analyzed using high-performance liquid chromatography (HPLC) for degradation products. Likewise, biodistribution was performed after injection of [{sup 67}Ga]SB3 (37 kBq, 100 μL, 10 pmol peptide) in severe combined immunodeficiency (SCID) mice bearing PC-3 xenografts. Eventually, [{sup 68}Ga]SB3 (283 ± 91 MBq, 23 ± 7 nmol) was injected into 17 patients with breast (8) and prostate (9) cancer. All patients had disseminated disease and had received previous therapies. PET/CT fusion images were acquired 60-115 min pi. SB3 and [{sup nat}Ga]SB3 bound to the human GRPR with high affinity (IC{sub 50}: 4.6 ± 0.5 nM and 1.5 ± 0.3 nM, respectively). [{sup 67}Ga]SB3 displayed good in vivo stability (>85 % intact at 5 min pi). [{sup 67}Ga]SB3 showed high, GRPR-specific and prolonged retention in PC-3 xenografts (33.1 ± 3.9%ID/g at 1 h pi - 27.0 ± 0.9%ID/g at 24 h pi), but much faster clearance from the GRPR-rich pancreas (∼160%ID/g at 1 h pi to <17%ID/g at 24 h pi) in mice. In patients, [{sup 68}Ga]SB3 elicited no adverse effects and

  4. In vivo stabilization of a gastrin-releasing peptide receptor antagonist enhances pet imaging and radionuclide therapy of prostate cancer in preclinical studies

    NARCIS (Netherlands)

    K.L.S. Chatalic (Kristell); M. Konijnenberg (Mark); J. Nonnekens (Julie); E. de Blois (Erik); S. Hoeben (Sander); C.M.A. Ridder (Corrina); L. Brunel (Luc); J.-A. Fehrentz (Jean-Alain); J. Martinez (Jean); D.C. van Gent (Dik); B.A. Nock (Berthold); T. Maina (Theodosia); W.M. van Weerden (Wytske); M. Jong (Marion de)

    2016-01-01

    textabstractA single tool for early detection, accurate staging, and personalized treatment of prostate cancer (PCa) would be a major breakthrough in the field of PCa. Gastrin-releasing peptide receptor (GRPR) targeting peptides are promising probes for a theranostic approach for PCa overexpressing

  5. Kunitz-Type Peptide HCRG21 from the Sea Anemone Heteractis crispa Is a Full Antagonist of the TRPV1 Receptor

    Directory of Open Access Journals (Sweden)

    Margarita Monastyrnaya

    2016-12-01

    Full Text Available Sea anemone venoms comprise multifarious peptides modulating biological targets such as ion channels or receptors. The sequence of a new Kunitz-type peptide, HCRG21, belonging to the Heteractis crispa RG (HCRG peptide subfamily was deduced on the basis of the gene sequence obtained from the Heteractis crispa cDNA. HCRG21 shares high structural homology with Kunitz-type peptides APHC1–APHC3 from H. crispa, and clusters with the peptides from so named “analgesic cluster” of the HCGS peptide subfamily but forms a separate branch on the NJ-phylogenetic tree. Three unique point substitutions at the N-terminus of the molecule, Arg1, Gly2, and Ser5, distinguish HCRG21 from other peptides of this cluster. The trypsin inhibitory activity of recombinant HCRG21 (rHCRG21 was comparable with the activity of peptides from the same cluster. Inhibition constants for trypsin and α-chymotrypsin were 1.0 × 10−7 and 7.0 × 10−7 M, respectively. Electrophysiological experiments revealed that rHCRG21 inhibits 95% of the capsaicin-induced current through transient receptor potential family member vanilloid 1 (TRPV1 and has a half-maximal inhibitory concentration of 6.9 ± 0.4 μM. Moreover, rHCRG21 is the first full peptide TRPV1 inhibitor, although displaying lower affinity for its receptor in comparison with other known ligands. Macromolecular docking and full atom Molecular Dynamics (MD simulations of the rHCRG21–TRPV1 complex allow hypothesizing the existence of two feasible, intra- and extracellular, molecular mechanisms of blocking. These data provide valuable insights in the structural and functional relationships and pharmacological potential of bifunctional Kunitz-type peptides.

  6. Rational design of DKK3 structure-based small peptides as antagonists of Wnt signaling pathway and in silico evaluation of their efficiency.

    Directory of Open Access Journals (Sweden)

    Mansour Poorebrahim

    Full Text Available Dysregulated Wnt signaling pathway is highly associated with the pathogenesis of several human cancers. Dickkopf proteins (DKKs are thought to inhibit Wnt signaling pathway through binding to lipoprotein receptor-related protein (LRP 5/6. In this study, based on the 3-dimensional (3D structure of DKK3 Cys-rich domain 2 (CRD2, we have designed and developed several peptide inhibitors of Wnt signaling pathway. Modeller 9.15 package was used to predict 3D structure of CRD2 based on the Homology modeling (HM protocol. After refinement and minimization with GalaxyRefine and NOMAD-REF servers, the quality of selected models was evaluated utilizing VADAR, SAVES and ProSA servers. Molecular docking studies as well as literature-based information revealed two distinct boxes located at CRD2 which are actively involved in the DKK3-LRP5/6 interaction. A peptide library was constructed conducting the backrub sequence tolerance scanning protocol in Rosetta3.5 according to the DKK3-LRP5/6 binding sites. Seven tolerated peptides were chosen and their binding affinity and stability were improved by some logical amino acid substitutions. Molecular dynamics (MD simulations of peptide-LRP5/6 complexes were carried out using GROMACS package. After evaluation of binding free energies, stability, electrostatic potential and some physicochemical properties utilizing computational approaches, three peptides (PEP-I1, PEP-I3 and PEP-II2 demonstrated desirable features. However, all seven improved peptides could sufficiently block the Wnt-binding site of LRP6 in silico. In conclusion, we have designed and improved several small peptides based on the LRP6-binding site of CRD2 of DKK3. These peptides are highly capable of binding to LRP6 in silico, and may prevent the formation of active Wnt-LRP6-Fz complex.

  7. Nogo-66 receptor antagonist peptide (NEP1-40) administration promotes functional recovery and axonal growth after lateral funiculus injury in the adult rat

    NARCIS (Netherlands)

    Cao, Y.; Shumsky, J. S.; Sabol, M. A.; Kushner, R. A.; Strittmatter, S.; Hamers, F. P. T.; Lee, D. H. S.; Rabacchi, S. A.; Murray, M.

    2008-01-01

    Objective. The myelin protein Nogo inhibits axon regeneration by binding to its receptor (NgR) on axons. Intrathecal delivery of an NgR antagonist (NEP1-40) promotes growth of injured corticospinal axons and recovery of motor function following a dorsal hemisection. The authors used a similar design

  8. A peptide antagonist of the ErbB1 receptor inhibits receptor activation, tumor cell growth and migration in vitro and xenograft tumor growth in vivo

    DEFF Research Database (Denmark)

    Xu, Ruodan; Povlsen, Gro Klitgaard; Soroka, Vladislav

    2010-01-01

    The epidermal growth factor family of receptor tyrosine kinases (ErbBs) plays essential roles in tumorigenesis and cancer disease progression, and therefore has become an attractive target for structure-based drug design. ErbB receptors are activated by ligand-induced homo- and heterodimerization......B1 phosphorylation, cell growth, and migration in two human tumor cell lines, A549 and HN5, expressing moderate and high ErbB1 levels, respectively. Furthermore, we show that Inherbin3 inhibits tumor growth in vivo and induces apoptosis in a tumor xenograft model employing the human non-small cell...... lung cancer cell line A549. The Inherbin3 peptide may be a useful tool for investigating the mechanisms of ErbB receptor homo- and heterodimerization. Moreover, the here described biological effects of Inherbin3 suggest that peptide-based targeting of ErbB receptor dimerization is a promising anti...

  9. Functional characterization of a competitive peptide antagonist of p65 in human macrophage-like cells suggests therapeutic potential for chronic inflammation

    Directory of Open Access Journals (Sweden)

    Srinivasan M

    2014-12-01

    Full Text Available Mythily Srinivasan,1 Corinne Blackburn,1 Debomoy K Lahiri2,3 1Department of Oral Pathology, Medicine and Radiology, Indiana University School of Dentistry, 2Institute of Psychiatry Research, Department of Psychiatry, 3Department of Medical and Molecular Genetics, School of Medicine, Indiana University-Purdue University, Indianapolis, IN, USA Abstract: Glucocorticoid-induced leucine zipper (GILZ is a glucocorticoid responsive protein that links the nuclear factor-kappa B (NFκB and the glucocorticoid signaling pathways. Functional and binding studies suggest that the proline-rich region at the carboxy terminus of GILZ binds the p65 subunit of NFκB and suppresses the immunoinflammatory response. A widely-used strategy in the discovery of peptide drugs involves exploitation of the complementary surfaces of naturally occurring binding partners. Previously, we observed that a synthetic peptide (GILZ-P derived from the proline-rich region of GILZ bound activated p65 and ameliorated experimental encephalomyelitis. Here we characterize the secondary structure of GILZ-P by circular dichroic analysis. GILZ-P adopts an extended polyproline type II helical conformation consistent with the structural conformation commonly observed in interfaces of transient intermolecular interactions. To determine the potential application of GILZ-P in humans, we evaluated the toxicity and efficacy of the peptide drug in mature human macrophage-like THP-1 cells. Treatment with GILZ-P at a wide range of concentrations commonly used for peptide drugs was nontoxic as determined by cell viability and apoptosis assays. Functionally, GILZ-P suppressed proliferation and glutamate secretion by activated macrophages by inhibiting nuclear translocation of p65. Collectively, our data suggest that the GILZ-P has therapeutic potential in chronic CNS diseases where persistent inflammation leads to neurodegeneration such as multiple sclerosis and Alzheimer’s disease. Keywords

  10. RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Vera L. Oliveira-Freitas

    2015-01-01

    Full Text Available RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR, RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P<0.001. The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P=0.005. Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P<0.013. No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β (P=0.159 and TNF-α (P=0.260, as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis.

  11. Antagonistic Properties of Some Halophilic Thermoactinomycetes Isolated from Superficial Sediment of a Solar Saltern and Production of Cyclic Antimicrobial Peptides by the Novel Isolate Paludifilum halophilum

    Science.gov (United States)

    Frikha Dammak, Donyez; Zarai, Ziad; Najah, Soumaya; Abdennabi, Rayed; Belbahri, Lassaad; Rateb, Mostafa E.; Mejdoub, Hafedh

    2017-01-01

    This study has focused on the isolation of twenty-three halophilic actinomycetes from two ponds of different salinity and the evaluation of their ability to exert an antimicrobial activity against both their competitors and several other pathogens. From the 23 isolates, 18 strains showed antagonistic activity, while 19 showed activities against one or more of the seven pathogen strains tested. Six strains exhibited consistent antibacterial activity against Gram-negative and Gram-positive pathogens characterized at the physiological and molecular levels. These strains shared only 94-95% 16S rRNA sequence identity with the closely related species of the Thermoactinomycetaceae family. Among them, the potent strain SMBg3 was further characterized and assigned to a new genus in the family for which the name Paludifilum halophilum (DSM 102817T) is proposed. Sequential extraction of the antimicrobial compounds with ethyl acetate revealed that the crude extract from SMBg3 strain had inhibitory effect on the growth of the plant pathogen Agrobacterium tumefaciens and the human pathogens Staphylococcus aureus, Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa. Based on the HRESI-MS spectral data, the cyclic lipopeptide Gramicidin S and four cyclic dipeptides (CDPs) named cyclo(L-4-OH-Pro-L-Leu), cyclo(L-Tyr-L-Pro), cyclo(L-Phe-L-Pro), and cyclo(L-Leu-L-Pro) were detected in the fermentation broth of Paludifilum halophilum. To our knowledge, this is the first report on the isolation of these compounds from members of the Thermoactinomycetaceae family. PMID:28819625

  12. Advancing drug therapy for brain tumours: a current review of the pro-inflammatory peptide Substance P and its antagonists as anti-cancer agents.

    Science.gov (United States)

    Mander, Kimberley; Harford-Wright, Elizabeth; Lewis, Kate M; Vink, Robert

    2014-01-01

    Evidence for the involvement of the Substance P (SP)/NK1 receptor system in the development and progression of cancer strongly supports its potential as a therapeutic target in malignancies. Novel strategies for approaching cancer treatment are urgently required particularly with regard to tumours of the central nervous system (CNS), which are notoriously difficult to effectively treat and associated with extremely poor prognosis for many patients. This is due, in part, to the presence of the highly specialised blood-brain barrier, which is known to restrict common treatments such as chemotherapy and hinder early tumour diagnosis. Additionally, tumours of the CNS are difficult to surgically resect completely, often contributing to the resurgence of the disease many years later. Interestingly, despite the presence of the blood-brain barrier, circulating tumour cells are able to gain entry to the brain and form secondary brain tumours; however, the underlying mechanisms of this process remain unclear. Tachykinins, in particular Substance P, have been implicated in early blood-brain barrier disruption via neurogenic inflammation in a number of other CNS pathologies. Recent evidence also suggests that Substance P may play a central role in the development of CNS tumours. It has been well established that a number of tumour cells express Substance P, NK1 receptors and mRNA for the tachykinin NK1 receptor. This increase in the Substance P/NK1 receptor system is known to induce proliferation and migration of tumour cells as well as stimulate angiogenesis, thus contributing to tumour progression. Accordingly, the NK1 receptor antagonist presents a novel target for anti-cancer therapy for which a number of patents have been filed. This review will examine the role of Substance P in the development of CNS tumours and its potential application as an anti-cancer agent.

  13. GABAB antagonists

    DEFF Research Database (Denmark)

    Frydenvang, Karla Andrea; Hansen, J J; Krogsgaard-Larsen, P

    1994-01-01

    chromatographic techniques. The absolute stereochemistry of (-)-(R)-phaclofen was established by X-ray crystallographic analysis. (-)-(R)-Phaclofen was shown to inhibit the binding of [3H]-(R)-baclofen to GABAB receptor sites on rat cerebellar membranes (IC50 = 76 +/- 13 microM), whereas (+)-(S......)-baclofen and the antagonist (-)-(R)-phaclofen suggests that these ligands interact with the GABAB receptor sites in a similar manner. Thus, it may be concluded that the different pharmacological effects of these compounds essentially result from the different spatial and proteolytic properties of their acid groups....

  14. Rationally designed transmembrane peptide mimics of the multidrug transporter protein Cdr1 act as antagonists to selectively block drug efflux and chemosensitize azole-resistant clinical isolates of Candida albicans.

    Science.gov (United States)

    Maurya, Indresh Kumar; Thota, Chaitanya Kumar; Verma, Sachin Dev; Sharma, Jyotsna; Rawal, Manpreet Kaur; Ravikumar, Balaguru; Sen, Sobhan; Chauhan, Neeraj; Lynn, Andrew M; Chauhan, Virander Singh; Prasad, Rajendra

    2013-06-07

    Drug-resistant pathogenic fungi use several families of membrane-embedded transporters to efflux antifungal drugs from the cells. The efflux pump Cdr1 (Candida drug resistance 1) belongs to the ATP-binding cassette (ABC) superfamily of transporters. Cdr1 is one of the most predominant mechanisms of multidrug resistance in azole-resistant (AR) clinical isolates of Candida albicans. Blocking drug efflux represents an attractive approach to combat the multidrug resistance of this opportunistic human pathogen. In this study, we rationally designed and synthesized transmembrane peptide mimics (TMPMs) of Cdr1 protein (Cdr1p) that correspond to each of the 12 transmembrane helices (TMHs) of the two transmembrane domains of the protein to target the primary structure of the Cdr1p. Several FITC-tagged TMPMs specifically bound to Cdr1p and blocked the efflux of entrapped fluorescent dyes from the AR (Gu5) isolate. These TMPMs did not affect the efflux of entrapped fluorescent dye from cells expressing the Cdr1p homologue Cdr2p or from cells expressing a non-ABC transporter Mdr1p. Notably, the time correlation of single photon counting fluorescence measurements confirmed the specific interaction of FITC-tagged TMPMs with their respective TMH. By using mutant variants of Cdr1p, we show that these TMPM antagonists contain the structural information necessary to target their respective TMHs of Cdr1p and specific binding sites that mediate the interactions between the mimics and its respective helix. Additionally, TMPMs that were devoid of any demonstrable hemolytic, cytotoxic, and antifungal activities chemosensitize AR clinical isolates and demonstrate synergy with drugs that further improved the therapeutic potential of fluconazole in vivo.

  15. Development of KGF Antagonist as a Breast Cancer Therapeutic

    National Research Council Canada - National Science Library

    Sugimoto, Yasuro

    2003-01-01

    .... We were able to show some potential intracellular KGFR target small molecules whereas extracellular target synthetic peptide antagonist was not able to do during this period We also added a new...

  16. Diagnosis of recurrent prostate cancer with PET/CT imaging using the gastrin-releasing peptide receptor antagonist {sup 68}Ga-RM2: Preliminary results in patients with negative or inconclusive [{sup 18}F]Fluoroethylcholine-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, Gesche; Bartholomae, Mark [University of Freiburg, Department of Nuclear Medicine, Medical Center -Faculty of Medicine, Freiburg (Germany); Popp, Ilinca; Grosu, Anca-Ligia [University of Freiburg, Department of Radiation Oncology, Medical Center - Faculty of Medicine, Freiburg (Germany); Christian Rischke, H. [University of Freiburg, Department of Nuclear Medicine, Medical Center -Faculty of Medicine, Freiburg (Germany); University of Freiburg, Department of Radiation Oncology, Medical Center - Faculty of Medicine, Freiburg (Germany); Drendel, Vanessa [University of Freiburg, Institute for Pathology, Faculty of Medicine, Freiburg (Germany); Weber, Wolfgang A. [Memorial Sloan Kettering Cancer Center, Molecular Imaging and Therapy Service, New York, NY (United States); Mansi, Rosalba [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Wetterauer, Ulrich; Schultze-Seemann, Wolfgang; Jilg, Cordula Annette [University of Freiburg, Department of Urology, Medical Center -Faculty of Medicine, Freiburg (Germany); Meyer, Philipp T. [University of Freiburg, Department of Nuclear Medicine, Medical Center -Faculty of Medicine, Freiburg (Germany); Partner Site Freiburg, German Cancer Consortium (DKTK), Freiburg (Germany)

    2017-08-15

    [{sup 18}F]fluoroethylcholine ({sup 18}FECH) has been shown to be a valuable PET-tracer in recurrent prostate cancer (PCa), but still has limited accuracy. RM2 is a gastrin-releasing peptide receptor (GRPr) antagonist that binds to GRPr on PCa cells. Recent studies suggest that GRPr imaging with PET/CT is a promising technique for staging and restaging of PCa. We explore the value of GRPr-PET using the {sup 68}Ga-labeled GRPr antagonist RM2 in a selected population of patients with biochemically recurrent PCa and a negative/inconclusive {sup 18}FECH-PET/CT. In this retrospective study 16 men with biochemical PCa relapse and negative (n = 14) or inconclusive (n = 2) {sup 18}FECH-PET/CT underwent whole-body {sup 68}Ga-RM2-PET/CT. Mean time from {sup 18}FECH-PET/CT to {sup 68}Ga-RM2-PET/CT was 6.1 ± 6.8 months. Primary therapies in these patients were radical prostatectomy (n = 13; 81.3%) or radiotherapy (n = 3; 18.7%). 14/16 patients (87.5%) had already undergone salvage therapies because of biochemical relapse prior to {sup 68}Ga-RM2-PET/CT imaging. Mean ± SD PSA at {sup 68}Ga-RM2-PET/CT was 19.4 ± 53.5 ng/ml (range 1.06-226.4 ng/ml). {sup 68}Ga-RM2-PET/CT showed at least one region with focal pathological uptake in 10/16 patients (62.5%), being suggestive of local relapse (n = 4), lymph node metastases (LNM; n = 4), bone metastases (n = 1) and lung metastasis with hilar LNM (n = 1). Seven of ten positive {sup 68}Ga-RM2 scans were positively confirmed by surgical resection and histology of the lesions (n = 2), by response to site-directed therapies (n = 2) or by further imaging (n = 3). Patients with a positive {sup 68}Ga-RM2-scan showed a significantly higher median PSA (6.8 ng/ml, IQR 10.2 ng/ml) value than those with a negative scan (1.5 ng/ml, IQR 3.1 ng/ml; p = 0.016). Gleason scores or concomitant antihormonal therapy had no apparent impact on the detection of recurrent disease. Even in this highly selected population of patients with known biochemical

  17. Possible site of action of CGRP antagonists in migraine

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer; Olesen, Jes

    2011-01-01

    The calcitonin gene-related peptide (CGRP) receptor antagonists olcegepant and telcagepant are very potent drugs. Both are effective in migraine but in doses much higher than would be predicted from receptor binding and other in vitro results. This could perhaps suggest an effect of CGRP antagoni......The calcitonin gene-related peptide (CGRP) receptor antagonists olcegepant and telcagepant are very potent drugs. Both are effective in migraine but in doses much higher than would be predicted from receptor binding and other in vitro results. This could perhaps suggest an effect of CGRP...... antagonists behind the blood-brain barrier (BBB), i.e. in the central nervous system (CNS)....

  18. ETA-receptor antagonists or allosteric modulators?

    DEFF Research Database (Denmark)

    De Mey, Jo G R; Compeer, Matthijs G; Lemkens, Pieter

    2011-01-01

    . In resistance arteries, the long-lasting contractile effects can only be partly and reversibly relaxed by low-molecular-weight ET(A) antagonists (ERAs). However, the neuropeptide calcitonin-gene-related peptide selectively terminates binding of ET1 to ET(A). We propose that ET1 binds polyvalently to ET......(A) and that ERAs and the physiological antagonist allosterically reduce ET(A) functions. Combining the two-state model and the two-domain model of GPCR function and considering receptor activation beyond agonist binding might lead to better anti-endothelinergic drugs. Future studies could lead to compounds...

  19. Single administration of p2TA (AB103, a CD28 antagonist peptide, prevents inflammatory and thrombotic reactions and protects against gastrointestinal injury in total-body irradiated mice.

    Directory of Open Access Journals (Sweden)

    Salida Mirzoeva

    Full Text Available The goal of this study was to elucidate the action of the CD28 mimetic peptide p2TA (AB103 that attenuates an excessive inflammatory response in mitigating radiation-induced inflammatory injuries. BALB/c and A/J mice were divided into four groups: Control (C, Peptide (P; 5 mg/kg of p2TA peptide, Radiation (R; total body irradiation with 8 Gy γ-rays, and Radiation + Peptide (RP; irradiation followed by p2TA peptide 24 h later. Gastrointestinal tissue damage was evaluated by analysis of jejunum histopathology and immunohistochemistry for cell proliferation (Cyclin D1 and inflammation (COX-2 markers, as well as the presence of macrophages (F4/80. Pro-inflammatory cytokines IL-6 and KC as well as fibrinogen were quantified in plasma samples obtained from the same mice. Our results demonstrated that administration of p2TA peptide significantly reduced the irradiation-induced increase of IL-6 and fibrinogen in plasma 7 days after exposure. Seven days after total body irradiation with 8 Gy of gamma rays numbers of intestinal crypt cells were reduced and villi were shorter in irradiated animals compared to the controls. The p2TA peptide delivery 24 h after irradiation led to improved morphology of villi and crypts, increased Cyclin D1 expression, decreased COX-2 staining and decreased numbers of macrophages in small intestine of irradiated mice. Our study suggests that attenuation of CD28 signaling is a promising therapeutic approach for mitigation of radiation-induced tissue injury.

  20. Peptides derived from self-proteins as partial agonists and antagonists of human CD8+ T-cell clones reactive to melanoma/melanocyte epitope MART1(27-35)

    DEFF Research Database (Denmark)

    Loftus, D J; Squarcina, P; Nielsen, M B

    1998-01-01

    to be ineffective in mediating tumor regression in vivo. We have noted previously that numerous peptides from both endogenous and foreign proteins are similar to MART1(27-35) and, potentially, are capable of productively engaging the T-cell receptors of patient-derived CTLs. This observation raised the question...... of whether CTLs in vivo might encounter self-peptide analogues of MART1(27-35) that lack full agonist activity, perhaps to the detriment of the antitumor CTL response. This possibility was evaluated using cloned, patient-derived CTLs with a panel of self-derived natural analogues of MART1(27-35) in assays...

  1. Peptides derived from self-proteins as partial agonists and antagonists of human CD8+ T-cell clones reactive to melanoma/melanocyte epitope MART1(27-35)

    DEFF Research Database (Denmark)

    Loftus, D J; Squarcina, P; Nielsen, M B

    1998-01-01

    The self-peptide MART1(27-35) derives from the melanocyte/melanoma protein Melan A/MART1 and is a target epitope of CD8+ T cells, commonly recovered from tumor-infiltrating lymphocytes of HLA-A2.1+ melanoma patients. Despite their prevalence in such patients, these CTLs generally appear to be ine......The self-peptide MART1(27-35) derives from the melanocyte/melanoma protein Melan A/MART1 and is a target epitope of CD8+ T cells, commonly recovered from tumor-infiltrating lymphocytes of HLA-A2.1+ melanoma patients. Despite their prevalence in such patients, these CTLs generally appear...

  2. CGRP receptor antagonists and antibodies against CGRP and its receptor in migraine treatment

    DEFF Research Database (Denmark)

    Edvinsson, Lars

    2015-01-01

    Recently developed calcitonin gene-related peptide (CGRP) receptor antagonistic molecules have shown promising results in clinical trials for acute treatment of migraine attacks. Drugs from the gepant class of CGRP receptor antagonists are effective and do not cause vasoconstriction, one...

  3. The Non-Peptide Arginine-Vasopressin v1a Selective Receptor Antagonist, SR49059, Blocks the Rewarding, Prosocial, and Anxiolytic Effects of 3,4-Methylenedioxymethamphetamine and Its Derivatives in Zebra Fish

    Directory of Open Access Journals (Sweden)

    Luisa Ponzoni

    2017-08-01

    Full Text Available 3,4-Methylenedioxymethamphetamine (MDMA and its derivatives, 2,5-dimethoxy-4-bromo-amphetamine hydrobromide (DOB and para-methoxyamphetamine (PMA, are recreational drugs whose pharmacological effects have recently been attributed to serotonin 5HT2A/C receptors. However, there is growing evidence that the oxytocin (OT/vasopressin system can modulate some the effects of MDMA. In this study, MDMA (2.5–10 mg/kg, DOB (0.5 mg/kg, or PMA (0.005, 0.1, or 0.25 mg/kg were administered intramuscularly to adult zebra fish, alone or in combination with the V1a vasopressin antagonist, SR49059 (0.01–1 ng/kg, before carrying out conditioned place preference (CPP, social preference, novel tank diving, and light–dark tests in order to evaluate subsequent rewarding, social, and emotional-like behavior. The combination of SR49059 and each drug progressively blocked: (1 rewarding behavior as measured by CPP in terms of time spent in drug-paired compartment; (2 prosocial effects measured on the basis of the time spent in the proximity of a nacre fish picture; and (3 anxiolytic effects in terms of the time spent in the upper half of the novel tank and in the white compartment of the tank used for the light–dark test. Antagonism was obtained at SR49059 doses which, when given alone, did not change motor function. In comparison with a control group, receiving vehicle alone, there was a three to five times increase in the brain release of isotocin (the analog of OT in fish after treatment with the most active doses of MDMA (10 mg/kg, DOB (0.5 mg/kg, and PMA (0.1 mg/kg as evaluated by means of bioanalytical reversed-phase high-performance liquid chromatography. Taken together, these findings show that the OT/vasopressin system is involved in the rewarding, prosocial, and anxiolytic effects of MDMA, DOB, and PMA in zebra fish and underline the association between this system and the behavioral alterations associated with disorders related to substance

  4. Peptide dendrimers

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2005-01-01

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

  5. Naloxone : actions of an antagonist

    NARCIS (Netherlands)

    Dorp, Eveline Louise Arianna van

    2009-01-01

    The opioid antagonist naloxone has a special place in pharmacology – it has no intrinsic action of its own, but it is able to save lives in the case of life threatening side-effects caused by other drugs. Naloxone is an antagonist for all opioid receptors, but most specifically for the μ-opioid

  6. Screening and Mechanism of Trapping Ligand Antagonist Peptide ...

    African Journals Online (AJOL)

    HP

    , and resuspended with 0.5 ml PBS. Samples were tested using FACSCalibur flow cytometer after filtration. All results were expressed as mean ± standard deviation (SD). Cross-linking of polypeptide H9 with receptors ORF74 and US28.

  7. Studies on antagonistic marine streptomycetes

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, D.; Nair, S.

    Sixty nine strains of Streptomyces sp. isolated from the sediments of Andaman and Nicobar islands (Bay of Bengal) were screened for their antagonistic property against a number of test cultures (Vibrio sp., Klebsiella sp., Escherichia coli, Shigella...

  8. 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

  9. Glucose-dependent insulinotropic polypeptide (GIP) receptor antagonists as anti-diabetic agents

    DEFF Research Database (Denmark)

    Gasbjerg, Lærke Smidt; Gabe, Maria Buur Nordskov; Hartmann, Bolette

    2018-01-01

    identified comprising both peptides, vaccines against GIP, GIP antibodies or antibodies against the GIPR. However, most of these have only been tested in rodents. In vitro, N- and C-terminally truncated GIP variants are potent and efficacious GIPR antagonists. Recently, GIP(3-30)NH2, a naturally occurring...

  10. Peptide ligand recognition by G protein-coupled receptors

    Directory of Open Access Journals (Sweden)

    Brian E Krumm

    2015-03-01

    Full Text Available The past few years have seen spectacular progress in the structure determination of G protein-coupled receptors (GPCRs. We now have structural representatives from classes A, B, C, and F. Within the rhodopsin-like class A, most structures belong to the α group, whereas fewer GPCR structures are available from the β, γ, and δ groups, which include peptide GPCRs such as the receptors for neurotensin (β group, opioids, chemokines (γ group, and protease-activated receptors (δ group. Structural information on peptide GPCRs is restricted to complexes with non-peptidic drug-like antagonists with the exception of the chemokine receptor CXCR4 that has been crystallized in the presence of a cyclic peptide antagonist. Notably, the neurotensin receptor (NTSR1 is to date the only peptide GPCR whose structure has been solved in the presence of a peptide agonist. Although limited in number, the current peptide GPCR structures reveal great diversity in shape and electrostatic properties of the ligand binding pockets, features that play key roles in the discrimination of ligands. Here, we review these aspects of peptide GPCRs in view of possible models for peptide agonist binding.

  11. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    International Nuclear Information System (INIS)

    Li, Qun-Yi; Zhang, Meng; Hallis, Tina M.; DeRosier, Therese A.; Yue, Jian-Min; Ye, Yang; Mais, Dale E.; Wang, Ming-Wei

    2010-01-01

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K i = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  12. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qun-Yi; Zhang, Meng [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Hallis, Tina M.; DeRosier, Therese A. [Cell Systems Division, Invitrogen, Madison, WI (United States); Yue, Jian-Min; Ye, Yang [State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Mais, Dale E. [The National Center for Drug Screening, Shanghai (China); MPI Research, Mattawan, MI (United States); Wang, Ming-Wei, E-mail: wangmw@mail.shcnc.ac.cn [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China)

    2010-01-15

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K{sub i} = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  13. Rational design of conformationally constrained cyclopentapeptide antagonists for C-x-C chemokine receptor 4 (CXCR4)

    DEFF Research Database (Denmark)

    Mungalpara, Jignesh; Thiele, Stefanie; Eriksen, Øystein

    2012-01-01

    In the absence of an experimentally determined binding mode for the cyclopentapeptide CXCR4 antagonists, we have rationally designed conformationally constrained analogues to further probe the small peptide binding pocket of CXCR4. Two different rigidification strategies were employed, both...... resulting in highly potent ligands (9 and 13). The information provided by this cyclopentapeptide ligand series will be very valuable in the development of novel peptidomimetic CXCR4 antagonists....

  14. Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ali Adem Bahar

    2013-11-01

    Full Text Available The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. The failure of the most potent antibiotics to kill “superbugs” emphasizes the urgent need to develop other control agents. Here we review the history and new development of antimicrobial peptides (AMPs, a growing class of natural and synthetic peptides with a wide spectrum of targets including viruses, bacteria, fungi, and parasites. We summarize the major types of AMPs, their modes of action, and the common mechanisms of AMP resistance. In addition, we discuss the principles for designing effective AMPs and the potential of using AMPs to control biofilms (multicellular structures of bacteria embedded in extracellular matrixes and persister cells (dormant phenotypic variants of bacterial cells that are highly tolerant to antibiotics.

  15. Bacterial antagonist mediated protein molecules

    OpenAIRE

    Urbizu, Lucia Paola; Sparo, Mónica Delfina; Sanchez Bruni, Sergio Fabian

    2016-01-01

    Bacterial antagonism mediated by ribosomally synthesised peptides has gained considerable attention in recent years because of its potential applications in the control of undesirable microbiota. These peptides, generally referred to as bacteriocins, are defined as a heterogeneous group of ribosomally synthesised, proteinaceous substances (with or without further modifications) extracellularly secreted by many Gram-positive and some Gram-negative bacteria. Their mode of activity is primarily ...

  16. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation...

  17. ANTAGONISTIC POTENTIAL OF FLUORESCENT Pseudomonas ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    This study focused on the antagonistic potential of fluorescent Pseudomonas in vitro, and its inoculation effect on growth performance of Lycopersicon esculentum in Fusarium oxysporum and Rhizoctonia solani infested soil. Biochemical characteristics of fluorescent Pseudomonas showed that all ten isolates were positive ...

  18. Design, synthesis, and biological evaluation of scaffold-based tripeptidomimetic antagonists for CXC chemokine receptor 4 (CXCR4)

    DEFF Research Database (Denmark)

    Zachariassen, Zack G; Thiele, Stefanie; Berg, Erik A

    2014-01-01

    Structure-activity relationship studies of the cyclopentapeptide CXCR4 antagonists (cyclo(-l-/d-Arg(1)-Arg(2)-2-Nal(3)-Gly(4)-d-Tyr(5)-)) suggest that the l-/d-Arg(1)-Arg(2)-2-Nal(3) tripeptide sequence contained within these cyclopentapeptides serves as a recognition motif for peptidic CXCR4...... antagonists. Starting by dissecting the cyclopentapeptide structure and reintroducing cyclic constraints in a stepwise manner, we here report a novel class of scaffold-based tripeptidomimetic CXCR4 antagonists based on the d-Arg-Arg-2-Nal motif. Biological testing of the prototype compounds showed...

  19. Progress in the development of oxytocin antagonists for use in preterm labor.

    Science.gov (United States)

    Williams, P D; Bock, M G; Evans, B E; Freidinger, R M; Pettibone, D J

    1998-01-01

    There is currently a need for new therapeutic agents for treating preterm labor which could offer improved safety and efficacy beyond what has been achieved with the widely employed beta-mimetics. In this regard, the longstanding hypothesis of oxytocin receptor blockade as representing a potentially more selective method of tocolysis has continued to gain support from results obtained in clinical studies with the peptide oxytocin antagonist, atosiban. Our laboratory has focussed on the identification of non-peptide oxytocin antagonists with properties suitable for both oral and intravenous administration. We have previously described the development of potent, camphor-based oxytocin antagonists, including L-368,899 which entered phase I human studies. More recently we have pursued a new structural class of oxytocin antagonists based on the 1-(N-benzoylpiperidin-4-yl)-4H-3,1-benzoxazin-2(1H)-one template. L-372,662 is a new member of this structural class and in our preclinical assays possesses an attractive overall profile from the standpoint of human oxytocin receptor affinity (Ki = 4.9 nM), human oxytocin vs. vasopressin receptor selectivity (> 500-fold), potency as an antagonist of oxytocin-induced uterine contractions in late gestation pregnant rhesus monkeys (AD50 = 36 micrograms/kg), oral bioavailability (F = 90% in dogs), and aqueous solubility (10 mg/mL).

  20. Involvement of calcitonin gene-related peptide in migraine

    DEFF Research Database (Denmark)

    Lassen, L H; Jacobsen, V B; Haderslev, P A

    2008-01-01

    Calcitonin gene-related peptide (CGRP)-containing nerves are closely associated with cranial blood vessels. CGRP is the most potent vasodilator known in isolated cerebral blood vessels. CGRP can induce migraine attacks, and two selective CGRP receptor antagonists are effective in the treatment...

  1. Tachykinin NK2 receptor antagonists. A patent review (2006 - 2010).

    Science.gov (United States)

    Altamura, Maria

    2012-01-01

    Tachykinins are endogenous peptide neurotransmitters, acting through the NK1, NK2 and NK3 receptors, at central and peripheral level. At peripheral level, they are involved in contraction of smooth muscle, secretion of water and ion from epithelia, as well as modulation of visceral pain sensitivity. Tachykinin NK2 receptor antagonists have the potential to be useful in the treatment of various gastrointestinal, genitourinary and CNS diseases. In this review, an overview of the patenting activity in the last 5 years is provided. Patents from different companies and research groups are discussed for their novelty and evaluated in relation to proposed indications and clinical studies. Relevant biological data are also presented. Patents claiming new therapeutic indications are included in a dedicated section. Although there is still no tachykinin NK2 receptor antagonist approved for use in human therapy, research in the field is still proposing new compounds and possible uses. A number of candidates are being evaluated in Phase II clinical studies, in indications ranging from gastrointestinal disorders to inflammatory diseases. The results of these studies will indicate the role of tachykinin NK2 receptor antagonists in human therapy.

  2. The latest developments in synthetic peptides with immunoregulatory activities.

    Science.gov (United States)

    Zhou, Chun-lei; Lu, Rong; Lin, Gang; Yao, Zhi

    2011-02-01

    In the past few years, many researches have provided us with much data demonstrating the abilities of synthetic peptides to impact immune response in vitro and in vivo. These peptides were designed according to the structure of some important protein molecules which play a key role in immune response, so they act with specific targets. The class I and II MHC-derived peptides inhibit the TCR recognition of antigen peptide-MHC complex. Rationally designed CD80 and CD154-binding peptides block the interaction between cell surface costimulatory molecules on antigen-presenting cells (APCs) and T cells. Some peptides were designed to inhibit the activities of cell signal proteins, including JNK, NF-κB and NFAT. Some peptide antagonists competitively bind to important cytokines and inhibit their activities, such as TNF-α, TGF-β and IL-1β inhibitory peptides. Adhesion molecule ICAM-1 derived peptides block the T cell adhesion and activation. These immunoregulatory peptides showed therapeutic effect in several animal models, including collagen-induced arthritis (CIA), autoimmune cystitis model, murine skin transplant model and cardiac allograft model. These results give us important implications for the development of a novel therapy for immune mediated diseases. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Synthetic antifreeze peptide

    OpenAIRE

    1991-01-01

    A synthetic antifreeze peptide and a synthetic gene coding for the antifreeze peptide have been produced. The antifreeze peptide has a greater number of repeating amino acid sequences than is present in the native antifreeze peptides from winter flounder upon which the synthetic antifreeze peptide was modeled. Each repeating amino acid sequence has two polar amino acid residues which are spaced a controlled distance apart so that the antifreeze peptide may inhibit ice formation. The synthetic...

  4. Construction, purification, and characterization of a chimeric TH1 antagonist

    Directory of Open Access Journals (Sweden)

    Javier-González Luís

    2006-05-01

    Full Text Available Abstract Background TH1 immune response antagonism is a desirable approach to mitigate some autoimmune and inflammatory reactions during the course of several diseases where IL-2 and IFN-γ are two central players. Therefore, the neutralization of both cytokines could provide beneficial effects in patients suffering from autoimmune or inflammatory illnesses. Results A chimeric antagonist that can antagonize the action of TH1 immunity mediators, IFN-γ and IL-2, was designed, engineered, expressed in E. coli, purified and evaluated for its in vitro biological activities. The TH1 antagonist molecule consists of the extracellular region for the human IFNγ receptor chain 1 fused by a four-aminoacid linker peptide to human 60 N-terminal aminoacid residues of IL-2. The corresponding gene fragments were isolated by RT-PCR and cloned in the pTPV-1 vector. E. coli (W3110 strain was transformed with this vector. The chimeric protein was expressed at high level as inclusion bodies. The protein was partially purified by pelleting and washing. It was then solubilized with strong denaturant and finally refolded by gel filtration. In vitro biological activity of chimera was demonstrated by inhibition of IFN-γ-dependent HLA-DR expression in Colo 205 cells, inhibition of IFN-γ antiproliferative effect on HEp-2 cells, and by a bidirectional effect in assays for IL-2 T-cell dependent proliferation: agonism in the absence versus inhibition in the presence of IL-2. Conclusion TH1 antagonist is a chimeric protein that inhibits the in vitro biological activities of human IFN-γ, and is a partial agonist/antagonist of human IL-2. With these attributes, the chimera has the potential to offer a new opportunity for the treatment of autoimmune and inflammatory diseases.

  5. Crystal Structures of Human Orexin 2 Receptor Bound to the Subtype-Selective Antagonist EMPA.

    Science.gov (United States)

    Suno, Ryoji; Kimura, Kanako Terakado; Nakane, Takanori; Yamashita, Keitaro; Wang, Junmei; Fujiwara, Takaaki; Yamanaka, Yasuaki; Im, Dohyun; Horita, Shoichiro; Tsujimoto, Hirokazu; Tawaramoto, Maki S; Hirokawa, Takatsugu; Nango, Eriko; Tono, Kensuke; Kameshima, Takashi; Hatsui, Takaki; Joti, Yasumasa; Yabashi, Makina; Shimamoto, Keiko; Yamamoto, Masaki; Rosenbaum, Daniel M; Iwata, So; Shimamura, Tatsuro; Kobayashi, Takuya

    2018-01-02

    Orexin peptides in the brain regulate physiological functions such as the sleep-wake cycle, and are thus drug targets for the treatment of insomnia. Using serial femtosecond crystallography and multi-crystal data collection with a synchrotron light source, we determined structures of human orexin 2 receptor in complex with the subtype-selective antagonist EMPA (N-ethyl-2-[(6-methoxy-pyridin-3-yl)-(toluene-2-sulfonyl)-amino]-N-pyridin-3-ylmethyl-acetamide) at 2.30-Å and 1.96-Å resolution. In comparison with the non-subtype-selective antagonist suvorexant, EMPA contacted fewer residues through hydrogen bonds at the orthosteric site, explaining the faster dissociation rate. Comparisons among these OX 2 R structures in complex with selective antagonists and previously determined OX 1 R/OX 2 R structures bound to non-selective antagonists revealed that the residue at positions 2.61 and 3.33 were critical for the antagonist selectivity in OX 2 R. The importance of these residues for binding selectivity to OX 2 R was also revealed by molecular dynamics simulation. These results should facilitate the development of antagonists for orexin receptors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Discovery and Characterization of an Endogenous CXCR4 Antagonist

    Directory of Open Access Journals (Sweden)

    Onofrio Zirafi

    2015-05-01

    Full Text Available CXCL12-CXCR4 signaling controls multiple physiological processes and its dysregulation is associated with cancers and inflammatory diseases. To discover as-yet-unknown endogenous ligands of CXCR4, we screened a blood-derived peptide library for inhibitors of CXCR4-tropic HIV-1 strains. This approach identified a 16 amino acid fragment of serum albumin as an effective and highly specific CXCR4 antagonist. The endogenous peptide, termed EPI-X4, is evolutionarily conserved and generated from the highly abundant albumin precursor by pH-regulated proteases. EPI-X4 forms an unusual lasso-like structure and antagonizes CXCL12-induced tumor cell migration, mobilizes stem cells, and suppresses inflammatory responses in mice. Furthermore, the peptide is abundant in the urine of patients with inflammatory kidney diseases and may serve as a biomarker. Our results identify EPI-X4 as a key regulator of CXCR4 signaling and introduce proteolysis of an abundant precursor protein as an alternative concept for chemokine receptor regulation.

  7. Analogues of arginine vasopressin modified at position 2 with proline derivatives: selective antagonists of oxytocin in vitro

    Czech Academy of Sciences Publication Activity Database

    Sobolewski, D.; Prahl, A.; Slaninová, Jiřina; Lammek, B.

    2009-01-01

    Roč. 611, - (2009), s. 503-504 ISSN 0065-2598. [American Peptide Society Symposium /20./. 26.06.2007-30.06.2007, Montreal] Institutional research plan: CEZ:AV0Z40550506 Keywords : vasopressin * proline derivatives * oxytocin antagonists Subject RIV: CC - Organic Chemistry

  8. Conformational determination of potent antagonist analogues of oxytocin by nuclear magnetic resonance spectroscopy and molecular dynamics simulations

    Czech Academy of Sciences Publication Activity Database

    Kritsi, E.; Potamitis, C.; Zoumpoulakis, P.; Borovičková, Lenka; Slaninová, Jiřina; Assimomytis, N. L.; Magafa, V.; Cordopatis, P.

    2014-01-01

    Roč. 20, Suppl S1 (2014), S200-S201 ISSN 1075-2617. [European Peptide Symposium /33./. 31.08.2014-05.09.2014, Sofia ] Institutional support: RVO:61388963 Keywords : oxytocin analogues * antagonistic activity * NMR * molecular dynamics Subject RIV: CC - Organic Chemistry

  9. Human peptide transporters

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  10. [SYNTHETIC PEPTIDE VACCINES].

    Science.gov (United States)

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested.

  11. Smac mimetics as IAP antagonists.

    Science.gov (United States)

    Fulda, Simone

    2015-03-01

    As the Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in human cancers, they represent promising targets for therapeutic intervention. Small-molecule inhibitors of IAP proteins mimicking the endogenous IAP antagonist Smac, called Smac mimetics, neutralize IAP proteins and thereby promote the induction of cell death. Smac mimetics have been shown in preclinical models of human cancer to directly trigger cancer cell death or to sensitize for cancer cell death induced by a variety of cytotoxic stimuli. Smac mimetics are currently undergoing clinical evaluation in phase I/II trials, demonstrating that therapeutic targeting of IAP proteins has reached the clinical stage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. New tachykinin peptides and nociception

    Directory of Open Access Journals (Sweden)

    Toshikazu Nishimori

    2013-02-01

    Full Text Available Hemokinin-1 (HK-1 and endokinins are peptides predicted from a new mammalian tachykinin gene, TAC4. The amino acid sequences derived from rat/mouse HK-1 and human HK-1 are not identical; however, the effects induced by intracerebroventricular or intrathecal administration of HK-1 are attenuated by treatment with antagonists of neurokinin 1 (NK1 receptor, substance P (SP receptor, indicating that HK-1 is an agonist of the NK1 receptor. On the other hand, a growing body of evidence indicates that pharmacological characteristics of HK-1 and SP are always not identical, suggesting that the HK-1-preferred receptor may be involved in the effects of HK-1. Endokinins are derived from human TAC4 and consist of four endokinins, endokinin A (EKA, endokinin B (EKB, endokinin C (EKC and endokinin D (EKD. Effects induced by intrathecal administration of EKA/B (the common C-terminal decapeptide in EKA and EKB and SP were very similar, while the effects of SP and EKA/B were inhibited by EKC/D (the common C-terminal duodecapeptide in EKC and EKD. This inhibitory effect of EKC/D was derived from leucine at the carboxyl-terminus. These findings suggest that HK-1 and EKA/B have an agonistic effect, while EKC/D has an antagonistic effect on the NK1 receptor in nociceptive processing.

  13. AM-37 and ST-36 Are Small Molecule Bombesin Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Terry W. Moody

    2017-07-01

    Full Text Available While peptide antagonists for the gastrin-releasing peptide receptor (BB2R, neuromedin B receptor (BB1R, and bombesin (BB receptor subtype-3 (BRS-3 exist, there is a need to develop non-peptide small molecule inhibitors for all three BBR. The BB agonist (BA1 binds with high affinity to the BB1R, BB2R, and BRS-3. In this communication, small molecule BBR antagonists were evaluated using human lung cancer cells. AM-37 and ST-36 inhibited binding to human BB1R, BB2R, and BRS-3 with similar affinity (Ki = 1.4–10.8 µM. AM-13 and AM-14 were approximately an order of magnitude less potent than AM-37 and ST-36. The ability of BA1 to elevate cytosolic Ca2+ in human lung cancer cells transfected with BB1R, BB2R, and BRS-3 was antagonized by AM-37 and ST-36. BA1 increased tyrosine phosphorylation of the EGFR and ERK in lung cancer cells, which was blocked by AM-37 and ST-36. AM-37 and ST-36 reduced the growth of lung cancer cells that have BBR. The results indicate that AM-37 and ST-36 function as small molecule BB receptor antagonists.

  14. Antagonistic Donor Density Effect Conserved in Multiple Enterococcal Conjugative Plasmids

    Science.gov (United States)

    Bandyopadhyay, Arpan; O'Brien, Sofie; Frank, Kristi L.; Dunny, Gary M.

    2016-01-01

    ABSTRACT Enterococcus faecalis, a common causative agent of hospital-acquired infections, is resistant to many known antibiotics. Its ability to acquire and transfer resistance genes and virulence determinants through conjugative plasmids poses a serious concern for public health. In some cases, induction of transfer of E. faecalis plasmids results from peptide pheromones produced by plasmid-free recipient cells, which are sensed by the plasmid-bearing donor cells. These plasmids generally encode an inhibitory peptide that competes with the pheromone and suppresses self-induction of donors. We recently demonstrated that the inhibitor peptide encoded on plasmid pCF10 is part of a unique quorum-sensing system in which it functions as a “self-sensing signal,” reducing the response to the pheromone in a density-dependent fashion. Based on the similarities between regulatory features controlling conjugation in pAD1 and pAM373 and those controlling conjugation in pCF10, we hypothesized that these plasmids are likely to exhibit similar quorum-sensing behaviors. Experimental findings indicate that for both pAD1 and pAM373, high donor densities indeed resulted in decreased induction of the conjugation operon and reduced conjugation frequencies. This effect was restored by the addition of exogenous inhibitor, confirming that the inhibitor serves as an indicator for donor density. Donor density also affects cross-species conjugative plasmid transfer. Based on our experimental results, we propose models for induction and shutdown of the conjugation operon in pAD1 and pAM373. IMPORTANCE Enterococcus faecalis is a leading cause of hospital-acquired infections. Its ability to transfer antibiotic resistance and virulence determinants by sharing its genetic material with other bacteria through direct cell-cell contact via conjugation poses a serious threat. Two antagonistic signaling peptides control the transfer of plasmids pAD1 and pAM373: a peptide pheromone produced by

  15. Viability of D283 medulloblastoma cells treated with a histone deacetylase inhibitor combined with bombesin receptor antagonists.

    Science.gov (United States)

    Jaeger, Mariane; Ghisleni, Eduarda C; Fratini, Lívia; Brunetto, Algemir L; Gregianin, Lauro José; Brunetto, André T; Schwartsmann, Gilberto; de Farias, Caroline B; Roesler, Rafael

    2016-01-01

    Medulloblastoma (MB) comprises four distinct molecular subgroups, and survival remains particularly poor in patients with Group 3 tumors. Mutations and copy number variations result in altered epigenetic regulation of gene expression in Group 3 MB. Histone deacetylase inhibitors (HDACi) reduce proliferation, promote cell death and neuronal differentiation, and increase sensitivity to radiation and chemotherapy in experimental MB. Bombesin receptor antagonists potentiate the antiproliferative effects of HDACi in lung cancer cells and show promise as experimental therapies for several human cancers. Here, we examined the viability of D283 cells, which belong to Group 3 MB, treated with an HDACi alone or combined with bombesin receptor antagonists. D283 MB cells were treated with different doses of the HDACi sodium butyrate (NaB), the neuromedin B receptor (NMBR) antagonist BIM-23127, the gastrin releasing peptide receptor (GRPR) antagonist RC-3095, or combinations of NaB with each receptor antagonist. Cell viability was examined by cell counting. NaB alone or combined with receptor antagonists reduced cell viability at all doses tested. BIM-23127 alone did not affect cell viability, whereas RC-3095 at an intermediate dose significantly increased cell number. Although HDACi are promising agents to inhibit MB growth, the present results provide preliminary evidence that combining HDACi with bombesin receptor antagonists is not an effective strategy to improve the effects of HDACi against MB cells.

  16. New antagonist agents of neuropeptide y receptors

    Directory of Open Access Journals (Sweden)

    Ignacio Aldana

    2000-12-01

    Full Text Available In the CNS, NPY has been implicated in obesity and feeding, endocrine function and metabolism. Potent and selective rNPY antagonists will be able to probe the merits of this approach for the treatment of obesity. We report the synthesis and preliminary evaluation of some hydrazide derivatives as antagonists of rNPY.

  17. S179D prolactin: antagonistic agony!

    Science.gov (United States)

    Walker, Ameae M

    2007-09-30

    The aims of this review are three-fold: first, to collate what is known about the production and activities of phosphorylated prolactin (PRL), the latter largely, but not exclusively, as illustrated through the use of the molecular mimic, S179D PRL; second, to apply this and related knowledge to produce an updated model of prolactin-receptor interactions that may apply to other members of this cytokine super-family; and third, to promote a shift in the current paradigm for the development of clinically important growth antagonists. This third aim explains the title since, based on results with S179D PRL, it is proposed that agents which signal to antagonistic ends may be better therapeutics than pure antagonists-hence antagonistic agony. Since S179D PRL is not a pure antagonist, we have proposed the term selective prolactin receptor modulator (SPeRM) for this and like molecules.

  18. [Extracorporeal life support in calcium antagonist intoxication].

    Science.gov (United States)

    Groot, M W; Grewal, S; Meeder, H J; van Thiel, R J; den Uil, C A

    2017-01-01

    Intoxication with calcium antagonists is associated with poor outcome. Even mild calcium antagonist overdose may be fatal. A 51-year-old woman and a 51-year-old man came to the Accident and Emergency Department in severe shock after they had taken a calcium antagonist overdose. After extensive medicinal therapy had failed, they both needed extracorporeal life support (ECLS) as a bridge to recovery. In severe calcium antagonist overdose, the combination of vasoplegia and cardiac failure leads to refractory shock. ECLS temporarily supports the circulation and maintains organ perfusion. In this way ECLS functions as a bridge to recovery and may possibly save lives. Timely consultation with and referral to an ECLS centre is recommended in patients with calcium antagonist overdose.

  19. Peptide Based Radiopharmaceuticals: Specific Construct Approach

    Energy Technology Data Exchange (ETDEWEB)

    Som, P; Rhodes, B A; Sharma, S S

    1997-10-21

    RGD receptor with higher density. The results have indicated good diagnostic potential for their use in this clinical situation, as an imaging agent to diagnose ischemic renal injury and differentiate from other causes. Very promising results were obtained with newly developed tuftsin related metallopeptides. A number of these peptides displayed high potency (nM range) in imaging infection. Antagonists were successfully used to image experimentally induced abscesses in rodents. One of the antagonists, termed 99mTc-RMT-1, was evaluated in rabbits and dogs for its applicability as infection/inflammation imaging agent. Both in dog and rabbit infection/inflammation models 99mTc-RMT-1 could be used for rapid scintigraphic diagnosis. A very high and rapid uptake was observed in both soft tissue and bone infection providing a good target to background contrast. The agent also allowed distinction between bone fracture and osteomyelitis. All these results warrant human clinical trials with 99mTc-RMT-1 which may help replace hazardous ex-vivo WBC labeling procedures that are current clincial modality for imaging infection foci.

  20. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  1. Designer Natriuretic Peptides

    Science.gov (United States)

    Lee, Candace Y. W.; Lieu, Hsiao; Burnett, John C.

    2011-01-01

    Designer natriuretic peptides (NPs) are novel hybrid peptides that are engineered from the native NPs through addition, deletion, or substitution of amino acid(s) with a goal toward optimization of pharmacological actions while minimizing undesirable effects. In this article, selected peptides that were designed in our laboratory are reviewed, and future directions for research and development of designer NPs are discussed. PMID:19158603

  2. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  3. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  4. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  5. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  6. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  7. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  8. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  9. Switch from antagonist to agonist after addition of a DOTA chelator to a somatostatin analog

    International Nuclear Information System (INIS)

    Reubi, Jean Claude; Cescato, Renzo; Waser, Beatrice; Erchegyi, Judit; Rivier, Jean E.

    2010-01-01

    Peptide receptor targeting has become an increasingly attractive method to target tumors diagnostically and radiotherapeutically. Peptides linked to a variety of chelators have been developed for this purpose. They have, however, rarely been tested for their agonistic or antagonistic properties. We report here on a somatostatin antagonist that switched to an agonist upon coupling to a DOTA chelator. Two novel somatostatin analogs, 406-040-15 and its DOTA-coupled counterpart 406-051-20, with and without cold Indium labeling, were tested for their somatostatin receptor subtypes 1-5 (sst 1 -sst 5 ) binding affinity using receptor autoradiography. Moreover, they were tested functionally for their ability to affect sst 2 and sst 3 internalization in vitro in HEK293 cells stably expressing the human sst 2 or sst 3 receptor, using an immunofluorescence microscopy-based internalization assay. All three compounds were characterized as pan-somatostatin analogs having a high affinity for all five sst. In the sst 2 internalization assay, all three compounds showed an identical behavior, namely, a weak agonistic effect complemented by a weak antagonistic effect, compatible with the behavior of a partial agonist. Conversely, in the sst 3 internalization assay, 406-040-15 was a full antagonist whereas its DOTA-coupled counterpart, 406-051-20, with and without Indium labeling, switched to a full agonist. Adding the DOTA chelator to the somatostatin analog 406-040-15 triggers a switch at sst 3 receptor from an antagonist to an agonist. This indicates that potential radioligands for tumor targeting should always be tested functionally before further development, in particular if a chelator is added. (orig.)

  10. Opioid antagonists for alcohol dependence.

    Science.gov (United States)

    Rösner, Susanne; Hackl-Herrwerth, Andrea; Leucht, Stefan; Vecchi, Simona; Srisurapanont, Manit; Soyka, Michael

    2010-12-08

    Alcohol dependence belongs to the globally leading health risk factors. Therapeutic success of psychosocial programs for relapse prevention is moderate and could be increased by an adjuvant treatment with the opioid antagonists naltrexone and nalmefene. To determine the effectiveness and tolerability of opioid antagonists in the treatment of alcohol dependence. We searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE and CINAHL in January 2010 and inquired manufacturers and researchers for unpublished trials. All double-blind randomised controlled trials (RCTs) which compare the effects of naltrexone or nalmefene with placebo or active control on drinking-related outcomes. Two authors independently extracted outcome data. Trial quality was assessed by one author and cross-checked by a second author. Based on a total of 50 RCTs with 7793 patients, naltrexone reduced the risk of heavy drinking to 83% of the risk in the placebo group RR 0.83 (95% CI 0.76 to 0.90) and decreased drinking days by about 4%, MD -3.89 (95% CI -5.75 to -2.04). Significant effects were also demonstrated for the secondary outcomes of the review including heavy drinking days, MD - 3.25 (95% CI -5.51 to -0.99), consumed amount of alcohol, MD - 10.83 (95% CI -19.69 to -1.97) and gamma-glutamyltransferase, MD - 10.37 (95% CI -18.99 to -1.75), while effects on return to any drinking, RR 0.96 (95 CI 0.92 to 1.00) missed statistical significance. Side effects of naltrexone were mainly gastrointestinal problems (e.g. nausea: RD 0.10; 95% CI 0.07 to 0.13) and sedative effects (e.g. daytime sleepiness: RD 0.09; 95% CI 0.05 to 0.14). Based on a limited study sample, effects of injectable naltrexone and nalmefene missed statistical significance. Effects of industry-sponsored studies, RR 0.90 (95% CI 0.78 to 1.05) did not significantly differ from those of non-profit funded trials, RR 0.84 (95% CI 0.77 to 0.91) and the linear regression test did not indicate publication

  11. PXR antagonists and implication in drug metabolism

    Science.gov (United States)

    Mani, Sridhar; Dou, Wei; Redinbo, Matthew R.

    2013-01-01

    Adopted orphan nuclear receptor (NR), pregnane X receptor (PXR), plays a central role in the regulation of xeno- and endobiotic metabolism. Since the discovery of the functional role of PXR in 1998, there is evolving evidence for the role of PXR agonists in abrogating metabolic pathophysiology (e.g., cholestasis, hypercholesterolemia, and inflammation). However, more recently, it is clear that PXR is also an important mediator of adverse xeno- (e.g., enhances acetaminophen toxicity) and endobiotic (e.g., hepatic steatosis) metabolic phenotypes. Moreover, in cancer therapeutics, PXR activation can induce drug resistance, and there is growing evidence for tissue-specific enhancement of the malignant phenotype. Thus, in these instances, there may be a role for PXR antagonists. However, as opposed to the discovery efforts for PXR agonists, there are only a few antagonists described. The mode of action of these antagonists (e.g., sulforaphane) remains less clear. Our laboratory efforts have focused on this question. Since the original discovery of azoles analogs as PXR antagonists, we have preliminarily defined an important PXR antagonist pharmacophore and developed less-toxic PXR antagonists. In this review, we describe our published and unpublished findings on recent structure-function studies involving the azole chemical scaffold. Further work in the future is needed to fully define potent, more-selective PXR antagonists that may be useful in clinical application. PMID:23330542

  12. Preclinical development of a novel class of CXCR4 antagonist impairing solid tumors growth and metastases.

    Directory of Open Access Journals (Sweden)

    Luigi Portella

    Full Text Available The CXCR4/CXCL12 axis plays a role in cancer metastases, stem cell mobilization and chemosensitization. Proof of concept for efficient CXCR4 inhibition has been demonstrated in stem cell mobilization prior to autologous transplantation in hematological malignancies. Nevertheless CXCR4 inhibitors suitable for prolonged use as required for anticancer therapy are not available. To develop new CXCR4 antagonists a rational, ligand-based approach was taken, distinct from the more commonly used development strategy. A three amino acid motif (Ar-Ar-X in CXCL12, also found in the reverse orientation (X-Ar-Ar in the vMIP-II inhibitory chemokine formed the core of nineteen cyclic peptides evaluated for inhibition of CXCR4-dependent migration, binding, P-ERK1/2-induction and calcium efflux. Peptides R, S and I were chosen for evaluation in in vivo models of lung metastases (B16-CXCR4 and KTM2 murine osteosarcoma cells and growth of a renal cells xenograft. Peptides R, S, and T significantly reduced the association of the 12G5-CXCR4 antibody to the receptor and inhibited CXCL12-induced calcium efflux. The four peptides efficiently inhibited CXCL12-dependent migration at concentrations as low as 10 nM and delayed CXCL12-mediated wound healing in PES43 human melanoma cells. Intraperitoneal treatment with peptides R, I or S drastically reduced the number of B16-CXCR4-derived lung metastases in C57/BL mice. KTM2 osteosarcoma lung metastases were also reduced in Balb/C mice following CXCR4 inhibition. All three peptides significantly inhibited subcutaneous growth of SN12C-EGFP renal cancer cells. A novel class of CXCR4 inhibitory peptides was discovered. Three peptides, R, I and S inhibited lung metastases and primary tumor growth and will be evaluated as anticancer agents.

  13. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    to the harsh and selective gastrointestinal system, and development has lacked far behind injection therapy. Peptide acylation is a powerful tool to alter the pharmacokinetics, biophysical properties and chemical stability of injectable peptide drugs, primarily used to prolong blood circulation....... This work aims to characterize acylated analogues of two therapeutic peptides by systematically increasing acyl chain length in order to elucidate its influence on membrane interaction and intestinal cell translocation in vitro. The studied peptides are the 33 amino acid Glucagon-like peptide-2 (GLP-2...... peptides can increase in vitro intestinal permeability, modestly for GLP-2 and drastically for sCT, and might benefit oral delivery. GLP-2 results provide a well-founded predictive power for future peptide analogues, whereas sCT results hold great promise for future analogues, albeit with a larger...

  14. Activation of the insulin receptor (IR) by insulin and a synthetic peptide has different effects on gene expression in IR-transfected L6 myoblasts

    DEFF Research Database (Denmark)

    Jensen, M.; Palsgaard, J.; Borup, R.

    2008-01-01

    Single-chain peptides have been recently produced that display either mimetic or antagonistic properties against the insulin and IGF-1 (insulin-like growth factor 1) receptors. We have shown previously that the insulin mimetic peptide S597 leads to significant differences in receptor activation a...

  15. GABAA receptor partial agonists and antagonists

    DEFF Research Database (Denmark)

    Krall, Jacob; Balle, Thomas; Krogsgaard-Larsen, Niels

    2015-01-01

    to the local temporal pattern of GABA impact, enabling phasic or tonic inhibition. Specific GABAAR antagonists are essential tools for physiological and pharmacological elucidation of the different type of GABAAR inhibition. However, distinct selectivity among the receptor subtypes (populations) has been shown...... antagonists and describes the development of potent antagonists from partial agonists originally derived from the potent GABAAR agonist muscimol. In this process, several heterocyclic aromatic systems have been used in combination with structural models in order to map the orthosteric binding site...... and to reveal structural details to be used for obtaining potency and subtype selectivity. The challenges connected to functional characterization of orthosteric GABAAR partial agonists and antagonists, especially with regard to GABAAR stoichiometry and alternative binding sites are discussed. GABAAR...

  16. Calcium antagonists for aneurysmal subarachnoid haemorrhage

    NARCIS (Netherlands)

    Dorhout Mees, S. M.; Rinkel, G. J. E.; Feigin, V. L.; Algra, A.; van den Bergh, W. M.; Vermeulen, M.; van Gijn, J.

    2007-01-01

    BACKGROUND: Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has been incompletely elucidated, but vasospasm probably is a contributing factor. Experimental studies have suggested that calcium antagonists can prevent or reverse

  17. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    Science.gov (United States)

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  18. Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

    Energy Technology Data Exchange (ETDEWEB)

    Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, PO Box 62, Berne (Switzerland)

    2014-06-15

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the {sup 125}iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer {sup 125}I-GLP-1(7-36)amide. Receptor autoradiography studies with {sup 125}I-GLP-1(7-36)amide agonist or {sup 125}I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist {sup 125}I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer {sup 125}I-GLP-1(7-36)amide. For comparison, {sup 125}I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with {sup 125}I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

  19. Antagonist wear by polished zirconia crowns.

    Science.gov (United States)

    Hartkamp, Oliver; Lohbauer, Ulrich; Reich, Sven

    The aim of this in vivo study was to measure antagonist wear caused by polished monolithic posterior zirconia crowns over a 24-month period using the intraoral digital impression (IDI) technique. Thirteen zirconia crowns were placed in nine patients. The crowns and adjacent teeth were captured using an intraoral scanner (Lava C.O.S.). The corresponding antagonist teeth and the respective neighboring teeth were also scanned. Scanning was performed immediately after the restoration (baseline) as well as 12 and 24 months after crown placement. Geomagic Qualify software was used to superimpose the follow-up data sets onto the corresponding baseline data set, identify wear sites, and measure maximum vertical height loss in each individual wear site. Overall antagonist wear was then determined as the mean of wear rates measured in all of the individual antagonist units. In addition, wear rates in enamel and ceramic antagonists were analyzed as part of the scope of this study. The maximum mean wear with standard deviation (SD) in the overall sample with a total of nine patients, 13 antagonist units, and 98 evaluable wear sites was 86 ± 23 µm at 12 months, and 103 ± 39 µm at 24 months. The maximum mean wear in the enamel antagonist subgroup was 87 ± 41 µm at 12 months, and 115 ± 71 µm at 24 months; and in the ceramic antagonist subgroup 107 ± 22 µm at 12 months, and 120 ± 27 µm at 24 months. The wear rates determined in this study are comparable to those of existing studies. The IDI technique of wear analysis can be carried out in a practical manner and produces useful results.

  20. Breast Cancer Cells in Three-dimensional Culture Display an Enhanced Radioresponse after Coordinate Targeting of Integrin ?5?1 and Fibronectin

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin-Min; Onodera, Yasuhito; Bissell, Mina J; Park, Catherine C

    2010-04-07

    Tactics to selectively enhance cancer radioresponse are of great interest. Cancer cells actively elaborate and remodel their extracellular matrix (ECM) to aid in survival and progression. Previous work has shown that {beta}1-integrin inhibitory antibodies can enhance the growth-inhibitory and apoptotic responses of human breast cancer cell lines to ionizing radiation, either when cells are cultured in three-dimensional laminin-rich ECM (3D lrECM) or grown as xenografts in mice. Here, we show that a specific {alpha} heterodimer of {beta}1-integrin preferentially mediates a prosurvival signal in human breast cancer cells that can be specifically targeted for therapy. 3D lrECM culture conditions were used to compare {alpha}-integrin heterodimer expression in malignant and nonmalignant cell lines. Under these conditions, we found that expression of {alpha}5{beta}1-integrin was upregulated in malignant cells compared with nonmalignant breast cells. Similarly, we found that normal and oncofetal splice variants of fibronectin, the primary ECM ligand of {alpha}5{beta}1-integrin, were also strikingly upregulated in malignant cell lines compared with nonmalignant acini. Cell treatment with a peptide that disrupts the interactions of {alpha}5{beta}1-integrin with fibronectin promoted apoptosis in malignant cells and further heightened the apoptotic effects of radiation. In support of these results, an analysis of gene expression array data from breast cancer patients revealed an association of high levels of {alpha}5-integrin expression with decreased survival. Our findings offer preclinical validation of fibronectin and {alpha}5{beta}1-integrin as targets for breast cancer therapy.

  1. Plant peptide hormone signalling.

    Science.gov (United States)

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. © 2015 Authors; published by Portland Press Limited.

  2. Analogues of a potent oxytocin antagonist having a ureido group in the amino acid side chain in position 4 or 5

    Czech Academy of Sciences Publication Activity Database

    Flouret, G.; Chaloin, O.; Slaninová, Jiřina

    2004-01-01

    Roč. 10, Supplement (2004), s. 243 ISSN 1075-2617. [International /3./ and European Peptide Symposium /28./. 05.09.2004-10.09.2004, Praha] Institutional research plan: CEZ:AV0Z4055905 Keywords : oxytocin * antagonist * uterus in vitro Subject RIV: CE - Biochemistry

  3. Expression of complement C5a receptor and the viability of 4T1 tumor cells following agonist–antagonist treatment

    Directory of Open Access Journals (Sweden)

    Nurneqman Nashreq Kosni

    2016-01-01

    Conclusion: This experiment shows the presence of C5a receptor on 4T1 cell line. We believe that the antagonist peptide is eligible to be used widely in cancer immunotherapy field; but in vivo studies need to be carried out first in the future, as it will determine how these drugs affect the tumor cell growth.

  4. [Prediction of ETA oligopeptides antagonists from Glycine max based on in silico proteolysis].

    Science.gov (United States)

    Qiao, Lian-Sheng; Jiang, Lu-di; Luo, Gang-Gang; Lu, Fang; Chen, Yan-Kun; Wang, Ling-Zhi; Li, Gong-Yu; Zhang, Yan-Ling

    2017-02-01

    Oligopeptides are one of the the key pharmaceutical effective constituents of traditional Chinese medicine(TCM). Systematic study on composition and efficacy of TCM oligopeptides is essential for the analysis of material basis and mechanism of TCM. In this study, the potential anti-hypertensive oligopeptides from Glycine max and their endothelin receptor A (ETA) antagonistic activity were discovered and predicted based on in silico technologies.Main protein sequences of G. max were collected and oligopeptides were obtained using in silico gastrointestinal tract proteolysis. Then, the pharmacophore of ETA antagonistic peptides was constructed and included one hydrophobic feature, one ionizable negative feature, one ring aromatic feature and five excluded volumes. Meanwhile, three-dimensional structure of ETA was developed by homology modeling methods for further docking studies. According to docking analysis and consensus score, the key amino acid of GLN165 was identified for ETA antagonistic activity. And 27 oligopeptides from G. max were predicted as the potential ETA antagonists by pharmacophore and docking studies.In silico proteolysis could be used to analyze the protein sequences from TCM. According to combination of in silico proteolysis and molecular simulation, the biological activities of oligopeptides could be predicted rapidly based on the known TCM protein sequence. It might provide the methodology basis for rapidly and efficiently implementing the mechanism analysis of TCM oligopeptides. Copyright© by the Chinese Pharmaceutical Association.

  5. Peptide-Functionalized Luminescent Iridium Complexes for Lifetime Imaging of CXCR4 Expression

    NARCIS (Netherlands)

    Kuil, J.; Steunenberg, P.; Chin, P.T.K.; Oldenburg, J.; Jalink, K.; Velders, A.H.; Leeuwen, F.W.B. van

    2011-01-01

    The chemokine receptor 4 (CXCR4) is over-expressed in 23 types of cancer in which it plays a role in, among others, the metastatic spread. For this reason it is a potential biomarker for the field of diagnostic oncology. The antagonistic Ac-TZ14011 peptide, which binds to CXCR4, has been conjugated

  6. Antimicrobial Peptides in Reptiles

    Science.gov (United States)

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  7. Influence of the angiotensin II AT1 receptor antagonist irbesartan on ischemia/reperfusion injury in the dog heart

    NARCIS (Netherlands)

    Preckel, B.; Schlack, W.; Gonzàlez, M.; Obal, D.; Barthel, H.; Thämer, V.

    2000-01-01

    The aim of the present study was to investigate whether the non-peptide angiotensin II type 1 (AT1) receptor antagonist irbesartan (SR 47436, BMS 186295, 2-n-butyl-3 [2'-(1H-tetrazol-5-yl)-biphenyl-4-yl)methyl]-1,3-diaza-spiro [4,4]non-1-en-4-one) has myocardial protective effects during regional

  8. Calcitonin gene-related peptide antagonism and cluster headache

    DEFF Research Database (Denmark)

    Ashina, Håkan; Newman, Lawrence; Ashina, Sait

    2017-01-01

    Calcitonin gene-related peptide (CGRP) is a key signaling molecule involved in migraine pathophysiology. Efficacy of CGRP monoclonal antibodies and antagonists in migraine treatment has fueled an increasing interest in the prospect of treating cluster headache (CH) with CGRP antagonism. The exact...... role of CGRP and its mechanism of action in CH have not been fully clarified. A search for original studies and randomized controlled trials (RCTs) published in English was performed in PubMed and in ClinicalTrials.gov . The search term used was "cluster headache and calcitonin gene related peptide......" and "primary headaches and calcitonin gene related peptide." Reference lists of identified articles were also searched for additional relevant papers. Human experimental studies have reported elevated plasma CGRP levels during both spontaneous and glyceryl trinitrate-induced cluster attacks. CGRP may play...

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

    Directory of Open Access Journals (Sweden)

    J Lesitha Jeeva Kumari

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

  10. Coronary dilation with nitrocompounds and calcium antagonists.

    Science.gov (United States)

    Jost, S; Rafflenbeul, W; Lichtlen, P R

    1990-01-01

    The vasodilatory effects of nitrocompounds and calcium antagonists on epicardial coronary arteries represent substantial antianginal mechanisms in the presence of coronary vasospasm or eccentric coronary stenoses. With high doses of nitrocompounds, angiographically normal coronary segments can be dilated by an average of approx. 30%, some coronary stenoses even by up to 100%, usually without severe reduction of blood pressure. With calcium antagonists, a similar extent of dilation of normal coronary arteries and eccentric stenoses can be obtained. Our own group demonstrated an average dilation of normal coronary arteries of about 20% after intravenous administration of dihydropyridine calcium antagonists; however, the average systolic blood pressure dropped below 100 mmHg after these compounds. Hence, although in isolated human coronary arteries high concentrations of calcium antagonists were shown to induce a considerably greater vasodilation than nitrocompounds, the early drop in blood pressure prohibits a higher dosage of calcium antagonists in vivo. In the presence of coronary artery disease, particularly when associated with coronary vasospasm, a combination of the two groups of compounds might be recommendable, since an addition of the effects of coronary vasomotor tone is likely. Furthermore, the antianginal effects of a reduction of preload and afterload are complementary.

  11. Insulin C-peptide test

    Science.gov (United States)

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin the body produces and insulin someone injects ...

  12. The peptidomimetic Lau-(Lys-βNSpe)6-NH2 antagonizes formyl peptide receptor 2 expressed in mouse neutrophils

    DEFF Research Database (Denmark)

    Skovbakke, Sarah Line; Winther, Malene; Gabl, Michael

    2016-01-01

    /differences between the human and murine FPR family members is required. Compared to FPR1 and FPR2 expressed by human neutrophils, very little is known about agonist/antagonist recognition patterns for their murine orthologues, but now we have identified two potent and selective formylated peptide agonists (f...... to be devoid of effect on their murine orthologues as determined by their inability to inhibit superoxide release from murine neutrophils upon stimulation with receptor-specific agonists. The Boc-FLFLF peptide was found to be a selective antagonist for Fpr1, whereas the lipidated peptidomimetic Lau...

  13. The antiproliferative action of [D-Arg(1), D-Phe(5), D-Trp(7,9), LEU(11)] substance P analogue antagonist against small-cell- and non-small-cell lung cancer cells could be due to the pharmacological profile of its tachykinin receptor antagonist.

    Science.gov (United States)

    Munoz, M; Recio, S; Rosso, M; Redondo, M; Covenas, R

    2015-06-01

    It is known that in human lung cancer samples, both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cells express the neurokinin-1 (NK-1) receptor; that after binding to the NK-1 receptor the peptide substance P (SP) elicits tumour cell proliferation and an antiapoptotic effect. By contrast, it has been demonstrated that non-peptide NK-1 receptor antagonists, after binding to the NK-1 receptor and hence by blocking the SP action in SCLC/NSCLC, exert an antiproliferative action (inhibit lung cancer cell proliferation and induce the death of tumour cells by apoptosis). It is also known that SP peptide NK-1 receptor antagonists also called SP analogue antagonists (broad-spectrum GPCR antagonists, broad-spectrum neuropeptide antagonists or synthetic analogues of SP), also exert antiproliferative actions against SCLC/NSCLC. However, the underlying mechanisms involved in this antiproliferative action remain unknown. By using competition assays with SP, here we demonstrate that the antiproliferative action exerted by the [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)] SP analogue on human H-69 SCLC and COR-L23 NSCLC cell lines, occurs at least through the NK-1 receptor.

  14. Endothelin@25 – new agonists, antagonists, inhibitors and emerging research frontiers: IUPHAR Review 12

    Science.gov (United States)

    Maguire, J J; Davenport, A P

    2014-01-01

    Since the discovery of endothelin (ET)-1 in 1988, the main components of the signalling pathway have become established, comprising three structurally similar endogenous 21-amino acid peptides, ET-1, ET-2 and ET-3, that activate two GPCRs, ETA and ETB. Our aim in this review is to highlight the recent progress in ET research. The ET-like domain peptide, corresponding to prepro-ET-193–166, has been proposed to be co-synthesized and released with ET-1, to modulate the actions of the peptide. ET-1 remains the most potent vasoconstrictor in the human cardiovascular system with a particularly long-lasting action. To date, the major therapeutic strategy to block the unwanted actions of ET in disease, principally in pulmonary arterial hypertension, has been to use antagonists that are selective for the ETA receptor (ambrisentan) or that block both receptor subtypes (bosentan). Macitentan represents the next generation of antagonists, being more potent than bosentan, with longer receptor occupancy and it is converted to an active metabolite; properties contributing to greater pharmacodynamic and pharmacokinetic efficacy. A second strategy is now being more widely tested in clinical trials and uses combined inhibitors of ET-converting enzyme and neutral endopeptidase such as SLV306 (daglutril). A third strategy based on activating the ETB receptor, has led to the renaissance of the modified peptide agonist IRL1620 as a clinical candidate in delivering anti-tumour drugs and as a pharmacological tool to investigate experimental pathophysiological conditions. Finally, we discuss biased signalling, epigenetic regulation and targeting with monoclonal antibodies as prospective new areas for ET research. PMID:25131455

  15. Amelioration of cold injury-induced cortical brain edema formation by selective endothelin ETB receptor antagonists in mice.

    Science.gov (United States)

    Michinaga, Shotaro; Nagase, Marina; Matsuyama, Emi; Yamanaka, Daisuke; Seno, Naoki; Fuka, Mayu; Yamamoto, Yui; Koyama, Yutaka

    2014-01-01

    Brain edema is a potentially fatal pathological condition that often occurs in stroke and head trauma. Following brain insults, endothelins (ETs) are increased and promote several pathophysiological responses. This study examined the effects of ETB antagonists on brain edema formation and disruption of the blood-brain barrier in a mouse cold injury model (Five- to six-week-old male ddY mice). Cold injury increased the water content of the injured cerebrum, and promoted extravasation of both Evans blue and endogenous albumin. In the injury area, expression of prepro-ET-1 mRNA and ET-1 peptide increased. Intracerebroventricular (ICV) administration of BQ788 (ETB antagonist), IRL-2500 (ETB antagonist), or FR139317 (ETA antagonist) prior to cold injury significantly attenuated the increase in brain water content. Bolus administration of BQ788, IRL-2500, or FR139317 also inhibited the cold injury-induced extravasation of Evans blue and albumin. Repeated administration of BQ788 and IRL-2500 beginning at 24 h after cold injury attenuated both the increase in brain water content and extravasation of markers. In contrast, FR139317 had no effect on edema formation when administrated after cold injury. Cold injury stimulated induction of glial fibrillary acidic protein-positive reactive astrocytes in the injured cerebrum. Induction of reactive astrocytes after cold injury was attenuated by ICV administration of BQ788 or IRL-2500. These results suggest that ETB receptor antagonists may be an effective approach to ameliorate brain edema formation following brain insults.

  16. Anaphylactic shock: catecholamine actions in the responses to opioid antagonists.

    Science.gov (United States)

    Amir, S

    1988-01-01

    The pathophysiological consequences of endorphin release in anaphylactic shock were investigated through pharmacological studies using opiate antagonists (naloxone, naltrexone, natrexone methyl bromide) as well as agonists (morphine, beta-endorphin). These studies suggest that induction of anaphylaxis provokes the release of endogenous opioids, possibly from the hypothalamus, which contribute to the shock process by stimulating opiate receptors in the CNS. The mechanism of pathophysiologic action of endorphin in anaphylaxis involves, at least in part, inhibition of the central component of the sympatho-adrenalmedullary system. This results in reduced effectiveness of the sympathetic system to physiologically reverse the circulatory effects of the toxic mediators of anaphylaxis. Naloxone, by blocking endorphin action at CNS opiate receptors located at autonomic regulatory centers (e.g. hypothalamus), reverses the sympatho-inhibitory effect of the endorphin peptides. This results in increased central sympathetic outflow to peripheral sympathetic neuroeffector mechanisms; it affords improved sympathetic compensatory responses and increases survival. TRH and DT gamma E physiologically oppose the action of endorphins upon the autonomic system. They stimulate central sympathetic mechanisms through their own receptor systems and increase outflow to peripheral sympathetic effectors. This also results in improved circulatory function and survival.

  17. Nociceptin/orphanin FQ peptide receptors: pharmacology and clinical implications.

    Science.gov (United States)

    Chiou, L-C; Liao, Y-Y; Fan, P-C; Kuo, P-H; Wang, C-H; Riemer, C; Prinssen, E P

    2007-01-01

    The advance of functional genomics revealed the superfamily of G-protein coupled receptors (GPCRs). Hundreds of GPCRs have been cloned but many of them are orphan GPCRs with unidentified ligands. The first identified orphan GPCR is the opioid receptor like orphan receptor, ORL1. It was cloned in 1994 during the identification of opioid receptor subtypes and was de-orphanized in 1995 by the discovery of its endogenous ligand, nociceptin or orphanin FQ (N/OFQ). This receptor was renamed as N/OFQ peptide (NOP) receptor. Several selective ligands acting at NOP receptors or other anti-N/OFQ agents have been reported. These include N/OFQ-derived peptides acting as agonists (cyclo[Cys(10),Cys(14)]N/OFQ, [Arg(14), Lys(15)]N/OFQ, [pX]Phe(4)N/OFQ(1-13)-NH(2), UFP-102, [(pF)Phe(4),Aib(7), Aib(11),Arg(14),Lys(15)]N/OFQ-NH(2)) or antagonists (Phe(1)psi(CH(2)-NH)Gly(2)]N/OFQ(1-13)-NH(2), [Nphe(1)]N/OFQ(1-13)-NH(2), UFP-101, [Nphe(1), (pF)Phe(4),Aib(7),Aib(11),Arg(14),Lys(15)]N/OFQ-NH(2)), hexapeptides, other peptide derivatives (peptide III-BTD, ZP-120, OS-461, OS-462, OS-500), non-peptide agonists (NNC 63-0532, Ro 64-6198, (+)-5a compound, W-212393, 3-(4-piperidinyl)indoles, 3-(4-piperidinyl) pyrrolo[2,3-b]pyridines) and antagonists (TRK-820, J-113397, JTC-801, octahydrobenzimidazol-2-ones, 2-(1,2,4-oxadiazol-5-yl)-1 H-indole, N-benzyl-D-prolines, SB-612111), biostable RNA Spiegelmers specific against N/OFQ, and a functional antagonist, nocistatin. Buprenorphine and naloxone benzoylhydrazone are two opioid receptor ligands showing high affinity for NOP receptors. NOP receptor agonists might be beneficial in the treatment of pain, anxiety, stress-induced anorexia, cough, neurogenic bladder, edema, drug dependence, and, less promising, in cerebral ischemia and epilepsy, while antagonists might be of help in the management of pain, depression, dementia and Parkinsonism. N/OFQ is also involved in cardiovascular, gastrointestinal and immune regulation. Altered plasma levels of N

  18. CRTH2 antagonists in asthma: current perspectives

    Directory of Open Access Journals (Sweden)

    Singh D

    2017-12-01

    Full Text Available Dave Singh, Arjun Ravi, Thomas Southworth Division of Infection, Immunity and Respiratory Medicine, The Medicines Evaluation Unit, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, The University of Manchester, Manchester, UK Abstract: Chemoattractant receptor-homologous molecule expressed on TH2 cells (CRTH2 binds to prostaglandin D2. CRTH2 is expressed on various cell types including eosinophils, mast cells, and basophils. CRTH2 and prostaglandin D2 are involved in allergic inflammation and eosinophil activation. Orally administered CRTH2 antagonists are in clinical development for the treatment of asthma. The biology and clinical trial data indicate that CRTH2 antagonists should be targeted toward eosinophilic asthma. This article reviews the clinical evidence for CRTH2 involvement in asthma pathophysiology and clinical trials of CRTH2 antagonists in asthma. CRTH2 antagonists could provide a practical alternative to biological treatments for patients with severe asthma. Future perspectives for this class of drug are considered, including the selection of the subgroup of patients most likely to show a meaningful treatment response. Keywords: CRTH2, clinical trial, eosinophilic asthma, prostaglandin D2

  19. Carbon adaptation influence the antagonistic ability of ...

    African Journals Online (AJOL)

    Influences of carbon adaptation on antagonistic activities of three Pseudomonas aeruginosa strains V4, V7 and V10 against Fusarium oxysporum f. sp. melonis were determined in this study. Results from this study showed that the P. aeruginosa strains and their adapted strains significantly inhibited the growth of mycelium ...

  20. Calcium antagonists for aneurysmal subarachnoid haemorrhage

    NARCIS (Netherlands)

    Rinkel, G. J. E.; Feigin, V. L.; Algra, A.; van den Bergh, W. M.; Vermeulen, M.; van Gijn, J.

    2005-01-01

    BACKGROUND: Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has not been elucidated yet, but may be related to vasospasm. Experimental studies have indicated that calcium antagonists can prevent or reverse vasospasm and have

  1. Antagonistic properties of microogranisms associated with cassava ...

    African Journals Online (AJOL)

    The antagonistic properties of indigenous microflora from cassava starch, flour and grated cassava were investigated using the conventional streak, novel ring and well diffusion methods. Antagonism was measured by zone of inhibition between the fungal plug and bacterial streak/ring. Bacillus species were more effective ...

  2. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    Introduction: A frightening increase in the number of isolated multidrug resistant bacterial strains linked to the decline in novel antimicrobial drugs entering the market is a great cause for concern. Cationic antimicrobial peptides (AMPs) have lately been introduced as a potential new class...... of antimicrobial drugs, and computational methods utilizing molecular descriptors can significantly accelerate the development of new peptide drug candidates. Areas covered: This paper gives a broad overview of peptide and amino-acid scale descriptors available for AMP modeling and highlights which...

  3. The quantum chemical causality of pMHC-TCR biological avidity: Peptide atomic coordination data and the electronic state of agonist N termini

    Directory of Open Access Journals (Sweden)

    Georgios S.E. Antipas

    2015-06-01

    Full Text Available The quantum state of functional avidity of the synapse formed between a peptide-Major Histocompatibility Complex (pMHC and a T cell receptor (TCR is a subject not previously touched upon. Here we present atomic pair correlation meta-data based on crystalized tertiary structures of the Tax (HTLV-1 peptide along with three artificially altered variants, all of which were presented by the (Class I HLA-A201 protein in complexation with the human (CD8+ A6TCR. The meta-data reveal the existence of a direct relationship between pMHC-TCR functional avidity (agonist/antagonist and peptide pair distribution function (PDF. In this context, antagonist peptides are consistently under-coordinated in respect to Tax. Moreover, Density Functional Theory (DFT datasets in the BLYP/TZ2P level of theory resulting from relaxation of the H species on peptide tertiary structures reveal that the coordination requirement of agonist peptides is also expressed as a physical observable of the protonation state of their N termini: agonistic peptides are always found to retain a stable ammonium (NH3+ terminal group while antagonist peptides are not.

  4. Antagonist-Elicited Cannabis Withdrawal in Humans

    Science.gov (United States)

    Gorelick, David A.; Goodwin, Robert S.; Schwilke, Eugene; Schwope, David M.; Darwin, William D.; Kelly, Deanna L.; McMahon, Robert P.; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A.

    2013-01-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ9-tetrahydrocannabinol (THC) dosages (40–120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0–8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses. PMID:21869692

  5. Antagonist-elicited cannabis withdrawal in humans.

    Science.gov (United States)

    Gorelick, David A; Goodwin, Robert S; Schwilke, Eugene; Schwope, David M; Darwin, William D; Kelly, Deanna L; McMahon, Robert P; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A

    2011-10-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ⁹-tetrahydrocannabinol (THC) dosages (40-120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0-8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses.

  6. Identification and Characterization of a Novel IL-4 Receptor α Chain (IL-4Rα Antagonist to Inhibit IL-4 Signalling

    Directory of Open Access Journals (Sweden)

    Nayyar Ahmed

    2015-05-01

    Full Text Available Background/Aims: In recent times, allergy has become a financial, physical and psychological burden to the society as a whole. In allergic cascades, cytokine IL-4 binds to IL-4 receptor (IL-4R, consequently producing allergen-specific IgE antibodies by B cells. In addition, among other functions, IL-4 is also responsible for B and T cell proliferation and differentiation. Hence, characterization of novel antagonists that inhibit IL-4 signalling forms the overall aim of this study. Methods: Phage display was used to screen a random 12-mer synthetic peptide library with a human IL-4Rα to identify peptide candidates. Once identified, the peptides were commercially synthesized and used for in vitro immunoassays. Results: We have successfully used phage display to identify M13 phage clones that demonstrated specific binding to IL-4Rα. The peptide N1 was synthesized for use in ELISA, demonstrating significant binding to IL-4Rα and inhibiting interaction with cytokine IL-4. Furthermore, the peptide was tested in a transfected HEK-Blue IL-4 reporter cell line model, which produces alkaline phosphatase (AP. QUANTI-Blue, a substrate, breaks down in the presence of AP producing a blue coloration. Using this colorimetric analysis, >50% inhibition of IL-4 signalling was achieved. Conclusion: We have successfully identified and characterised a synthetic peptide antagonist against IL-4Rα, which effectively inhibits IL-4 interaction with the IL-4Rα in vitro. Since IL-4 interaction with IL-4Rα is a common pathway for many allergies, a prophylactic treatment can be devised by inhibiting this interaction for future treatment of allergies.

  7. Antimicrobial activity of extracellular metabolites from antagonistic bacteria isolated from potato (Solanum phureja crops

    Directory of Open Access Journals (Sweden)

    Sinar David Granada García

    2014-09-01

    Full Text Available Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.. Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.

  8. Similarities and differences between calcium antagonists: pharmacological aspects

    NARCIS (Netherlands)

    van Zwieten, P. A.; Pfaffendorf, M.

    1993-01-01

    Characteristics of three different calcium antagonist groups: Most important calcium antagonists used to treat cardiovascular disease belong to one of three main groups, phenylalkylamines, dihydropyridines and benzothiazepines. The best known drug in each group is verapamil, nifedipine and

  9. Protective effects of calcium antagonists in different organs and tissues

    NARCIS (Netherlands)

    van Zwieten, P. A.

    1993-01-01

    The therapeutic efficacy of calcium antagonists in ischemic disorders of various tissues is attributed to vasodilator and antivasoconstrictor activities. A direct, energy-conserving, antiischemic effect of certain calcium antagonists has been claimed repeatedly by basic scientists. The clinical

  10. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

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

  11. Tumor-Penetrating Peptides

    Science.gov (United States)

    Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

    2013-01-01

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

  12. Novel Endogenous Antimicrobial Peptides

    OpenAIRE

    Nordahl, Emma

    2009-01-01

    Antimicrobial peptides serve as a first line of defence against invading microorganisms and are an essential part of our fast innate immune system. They are ancient molecules found in all classes of life. Antimicrobial peptides rapidly kill a broad spectrum of microbes and are immunomodulatory, i.e. having additional actions influencing inflammation and other innate immune responses. Results presented in this thesis demonstrate that proteases of common human pathogens degrade and inactivate t...

  13. Discovery of Highly Potent Dual Orexin Receptor Antagonists via a Scaffold-Hopping Approach.

    Science.gov (United States)

    Heidmann, Bibia; Gatfield, John; Roch, Catherine; Treiber, Alexander; Tortoioli, Simone; Brotschi, Christine; Williams, Jodi T; Bolli, Martin H; Abele, Stefan; Sifferlen, Thierry; Jenck, François; Boss, Christoph

    2016-10-06

    Starting from suvorexant (trade name Belsomra), we successfully identified interesting templates leading to potent dual orexin receptor antagonists (DORAs) via a scaffold-hopping approach. Structure-activity relationship optimization allowed us not only to improve the antagonistic potency on both orexin 1 and orexin 2 receptors (Ox1 and Ox2, respectively), but also to increase metabolic stability in human liver microsomes (HLM), decrease time-dependent inhibition of cytochrome P450 (CYP) 3A4, and decrease P-glycoprotein (Pgp)-mediated efflux. Compound 80 c [{(1S,6R)-3-(6,7-difluoroquinoxalin-2-yl)-3,8-diazabicyclo[4.2.0]octan-8-yl}(4-methyl-[1,1'-biphenyl]-2-yl)methanone] is a potent and selective DORA that inhibits the stimulating effects of orexin peptides OXA and OXB at both Ox1 and Ox2. In calcium-release assays, 80 c was found to exhibit an insurmountable antagonistic profile at both Ox1 and Ox2, while displaying a sleep-promoting effect in rat and dog models, similar to that of the benchmark compound suvorexant. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Peptide aldehyde inhibitors of bacterial peptide deformylases.

    Science.gov (United States)

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

    1999-07-15

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

  15. In vitro pharmacological characterization of vorapaxar, a novel platelet thrombin receptor antagonist.

    Science.gov (United States)

    Hawes, Brian E; Zhai, Ying; Hesk, David; Wirth, Mark; Wei, Huijun; Chintala, Madhu; Seiffert, Dietmar

    2015-09-05

    Vorapaxar is a novel protease-activated receptor-1 (PAR1) antagonist recently approved for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction or with peripheral arterial disease. The present study provides a comprehensive in vitro pharmacological characterization of vorapaxar interaction with the PAR1 receptor on human platelets. Similar studies were performed with a metabolite of vorapaxar (M20). Vorapaxar and M20 were competitive PAR1 antagonists that demonstrated concentration-dependent, saturable, specific, and slowly reversible binding to the receptor present on intact human platelets. The affinities of vorapaxar and M20 for the PAR1 receptor were in the low nanomolar range, as determined by saturation-, kinetic- and competitive binding studies. The calculated Kd and Ki values for vorapaxar increased in the presence of plasma, indicating a decrease in the free fraction available for binding to the PAR1 receptor on human platelets. Vorapaxar was also evaluated in functional assays using thrombin or a PAR1 agonist peptide (SFLLRN). Vorapaxar and M20 completely blocked thrombin-stimulated PAR1/β-arrestin association in recombinant cells and abolished thrombin-stimulated calcium influx in washed human platelets and vascular smooth muscle cells. Moreover, vorapaxar and M20 inhibited PAR1 agonist peptide-mediated platelet aggregation in human platelet rich plasma with a steep concentration response relationship. Vorapaxar exhibited high selectivity for inhibition of PAR1 over other platelet GPCRs. In conclusion, vorapaxar is a potent PAR1 antagonist exhibiting saturable, reversible, selective binding with slow off-rate kinetics and effectively inhibits thrombin's PAR1-mediated actions on human platelets. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Granin-derived peptides.

    Science.gov (United States)

    Troger, Josef; Theurl, Markus; Kirchmair, Rudolf; Pasqua, Teresa; Tota, Bruno; Angelone, Tommaso; Cerra, Maria C; Nowosielski, Yvonne; Mätzler, Raphaela; Troger, Jasmin; Gayen, Jaur R; Trudeau, Vance; Corti, Angelo; Helle, Karen B

    2017-07-01

    The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Peptide Optical waveguides.

    Science.gov (United States)

    Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil

    2017-02-01

    Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  18. Antagonistic parent-offspring co-adaptation.

    Directory of Open Access Journals (Sweden)

    Mathias Kölliker

    2010-01-01

    Full Text Available In species across taxa, offspring have means to influence parental investment (PI. PI thus evolves as an interacting phenotype and indirect genetic effects may strongly affect the co-evolutionary dynamics of offspring and parental behaviors. Evolutionary theory focused on explaining how exaggerated offspring solicitation can be understood as resolution of parent-offspring conflict, but the evolutionary origin and diversification of different forms of family interactions remains unclear.In contrast to previous theory that largely uses a static approach to predict how "offspring individuals" and "parental individuals" should interact given conflict over PI, we present a dynamic theoretical framework of antagonistic selection on the PI individuals obtain/take as offspring and the PI they provide as parents to maximize individual lifetime reproductive success; we analyze a deterministic and a stochastic version of this dynamic framework. We show that a zone for equivalent co-adaptation outcomes exists in which stable levels of PI can evolve and be maintained despite fast strategy transitions and ongoing co-evolutionary dynamics. Under antagonistic co-adaptation, cost-free solicitation can evolve as an adaptation to emerging preferences in parents.We show that antagonistic selection across the offspring and parental life-stage of individuals favors co-adapted offspring and parental behavior within a zone of equivalent outcomes. This antagonistic parent-offspring co-adaptation does not require solicitation to be costly, allows for rapid divergence and evolutionary novelty and potentially explains the origin and diversification of the observed provisioning forms in family life.

  19. Antagonist potential of Trichoderma indigenous isolates for ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... Full Length Research Paper. Antagonist potential of Trichoderma indigenous isolates for biological control of Phytophthora palmivora the causative agent of black pod disease on cocoa (Theobroma cacao L.) in Côte d'Ivoire. J. Mpika1,4*, I. B. Kébé1, A. E. Issali2, F.K. N'Guessan1, S. Druzhinina3, ...

  20. Diversity-oriented peptide stapling

    DEFF Research Database (Denmark)

    Tran, Thu Phuong; Larsen, Christian Ørnbøl; Røndbjerg, Tobias

    2017-01-01

    The introduction of macrocyclic constraints in peptides (peptide stapling) is an important tool within peptide medicinal chemistry for stabilising and pre-organising peptides in a desired conformation. In recent years, the copper-catalysed azide-alkyne cycloaddition (CuAAC) has emerged as a power......The introduction of macrocyclic constraints in peptides (peptide stapling) is an important tool within peptide medicinal chemistry for stabilising and pre-organising peptides in a desired conformation. In recent years, the copper-catalysed azide-alkyne cycloaddition (CuAAC) has emerged...... incorporating two azide-modified amino acids with 1,3,5-triethynylbenzene efficiently provides (i, i+7)- and (i, i+9)-stapled peptides with a single free alkyne positioned on the staple, that can be further conjugated or dimerised. A unique feature of the present method is that it provides easy access...

  1. Substance P and Related Peptides: Cellular and Molecular Physiology. Annals of the New York Academy of Sciences. Volume 632

    Science.gov (United States)

    Peripheral Nervous System; Preprotachykinin Gene Expression in the Forebrain: Regulation by Dopamine; Differential Changes in Tachykinins in the Rat Brain... Tachykinin Receptors; Concepts in characterization of Tachykinin Receptors; Selective Neurokinin Receptor Radioligands; Myoinositol Uptake in Rat Parotid...Gland; Tachykinins in Autonomic Control Systems; Neurokinin Agonists and Antagonists; Tachykinins and Related Peptides in the Substantia Nigra and

  2. Medicinal Chemistry of Competitive Kainate Receptor Antagonists

    Science.gov (United States)

    2010-01-01

    Kainic acid (KA) receptors belong to the group of ionotropic glutamate receptors and are expressed throughout in the central nervous system (CNS). The KA receptors have been shown to be involved in neurophysiological functions such as mossy fiber long-term potentiation (LTP) and synaptic plasticity and are thus potential therapeutic targets in CNS diseases such as schizophrenia, major depression, neuropathic pain and epilepsy. Extensive effort has been made to develop subtype-selective KA receptor antagonists in order to elucidate the physiological function of each of the five subunits known (GluK1−5). However, to date only selective antagonists for the GluK1 subunit have been discovered, which underlines the strong need for continued research in this area. The present review describes the structure−activity relationship and pharmacological profile for 10 chemically distinct classes of KA receptor antagonists comprising, in all, 45 compounds. To the medicinal chemist this information will serve as reference guidance as well as an inspiration for future effort in this field. PMID:22778857

  3. The sexually antagonistic genes of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Paolo Innocenti

    2010-03-01

    Full Text Available When selective pressures differ between males and females, the genes experiencing these conflicting evolutionary forces are said to be sexually antagonistic. Although the phenotypic effect of these genes has been documented in both wild and laboratory populations, their identity, number, and location remains unknown. Here, by combining data on sex-specific fitness and genome-wide transcript abundance in a quantitative genetic framework, we identified a group of candidate genes experiencing sexually antagonistic selection in the adult, which correspond to 8% of Drosophila melanogaster genes. As predicted, the X chromosome is enriched for these genes, but surprisingly they represent only a small proportion of the total number of sex-biased transcripts, indicating that the latter is a poor predictor of sexual antagonism. Furthermore, the majority of genes whose expression profiles showed a significant relationship with either male or female adult fitness are also sexually antagonistic. These results provide a first insight into the genetic basis of intralocus sexual conflict and indicate that genetic variation for fitness is dominated and maintained by sexual antagonism, potentially neutralizing any indirect genetic benefits of sexual selection.

  4. Pharmacological analysis of calcium antagonist receptors

    International Nuclear Information System (INIS)

    Reynolds, I.J.

    1987-01-01

    This work focuses on two aspects of the action of calcium antagonist drugs, namely, the interaction of drugs with receptors for verapamil-like calcium antagonists, and the interactions of drugs with voltage-sensitive calcium fluxes in rat brain synaptosomes. From binding studies I have found that the ligand of choice for labeling the verapamil receptor is (-)[ 3 H]desmethoxy-verapamil. This drug labels potently, reversibly and stereoselectively two receptors in membranes prepared from rat brain and rabbit skeletal muscle tissues. In equilibrium studies dihydropyridine calcium antagonists interact in a non-competitive fashion, while many non-DHPs are apparently competitive. In-depth kinetic studies in skeletal muscle membranes indicate that the two receptors are linked in a negative heterotropic fashion, and that low-affinity binding of (-) [ 3 H]desmethoxy-verapamil may be to the diltiazem receptor. However, these studies were not able to distinguish between the hypothesis that diltiazem binds to spatially separate, allosterically coupled receptors, and the hypothesis that diltiazem binds to a subsite of the verapamil receptor

  5. NMDA Receptor Antagonists for Treatment of Depression

    Directory of Open Access Journals (Sweden)

    Zeynep Ates-Alagoz

    2013-04-01

    Full Text Available Depression is a psychiatric disorder that affects millions of people worldwide. Individuals battling this disorder commonly experience high rates of relapse, persistent residual symptoms, functional impairment, and diminished well-being. Medications have important utility in stabilizing moods and daily functions of many individuals. However, only one third of patients had considerable improvement with a standard antidepressant after 2 months and all patients had to deal with numerous side effects. The N-methyl-d-aspartate (NMDA receptor family has received special attention because of its critical role in psychiatric disorders. Direct targeting of the NMDA receptor could result in more rapid antidepressant effects. Antidepressant-like effects of NMDA receptor antagonists have been demonstrated in different animal models. MK-801 (a use-dependent channel blocker, and CGP 37849 (an NMDA receptor antagonist have shown antidepressant properties in preclinical studies, either alone or combined with traditional antidepressants. A recent development is use of ketamine clinically for refractory depression. The purpose of this review is to examine and analyze current literature on the role of NMDA receptor antagonists for treatment of depression and whether this is a feasible route in drug discovery.

  6. Peptide Integrated Optics.

    Science.gov (United States)

    Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

    2018-02-01

    Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The interleukin (IL)-1 cytokine family--Balance between agonists and antagonists in inflammatory diseases.

    Science.gov (United States)

    Palomo, Jennifer; Dietrich, Damien; Martin, Praxedis; Palmer, Gaby; Gabay, Cem

    2015-11-01

    The interleukin (IL)-1 family of cytokines comprises 11 members, including 7 pro-inflammatory agonists (IL-1α, IL-1β, IL-18, IL-33, IL-36α, IL-36β, IL-36γ) and 4 defined or putative antagonists (IL-1R antagonist (IL-1Ra), IL-36Ra, IL-37, and IL-38) exerting anti-inflammatory activities. Except for IL-1Ra, IL-1 cytokines do not possess a leader sequence and are secreted via an unconventional pathway. In addition, IL-1β and IL-18 are produced as biologically inert pro-peptides that require cleavage by caspase-1 in their N-terminal region to generate active proteins. N-terminal processing is also required for full activity of IL-36 cytokines. The IL-1 receptor (IL-1R) family comprises 10 members and includes cytokine-specific receptors, co-receptors and inhibitory receptors. The signaling IL-1Rs share a common structure with three extracellular immunoglobulin (Ig) domains and an intracellular Toll-like/IL-1R (TIR) domain. IL-1 cytokines bind to their specific receptor, which leads to the recruitment of a co-receptor and intracellular signaling. IL-1 cytokines induce potent inflammatory responses and their activity is tightly controlled at the level of production, protein processing and maturation, receptor binding and post-receptor signaling by naturally occurring inhibitors. Some of these inhibitors are IL-1 family antagonists, while others are IL-1R family members acting as membrane-bound or soluble decoy receptors. An imbalance between agonist and antagonist levels can lead to exaggerated inflammatory responses. Several genetic modifications or mutations associated with dysregulated IL-1 activity and autoinflammatory disorders were identified in mouse models and in patients. These findings paved the road to the successful use of IL-1 inhibitors in diseases that were previously considered as untreatable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. From the Cover: Glutamate antagonists limit tumor growth

    Science.gov (United States)

    Rzeski, Wojciech; Turski, Lechoslaw; Ikonomidou, Chrysanthy

    2001-05-01

    Neuronal progenitors and tumor cells possess propensity to proliferate and to migrate. Glutamate regulates proliferation and migration of neurons during development, but it is not known whether it influences proliferation and migration of tumor cells. We demonstrate that glutamate antagonists inhibit proliferation of human tumor cells. Colon adenocarcinoma, astrocytoma, and breast and lung carcinoma cells were most sensitive to the antiproliferative effect of the N-methyl-D-aspartate antagonist dizocilpine, whereas breast and lung carcinoma, colon adenocarcinoma, and neuroblastoma cells responded most favorably to the -amino-3-hydroxy-5-methyl-4-isoxazole-propionate antagonist GYKI52466. The antiproliferative effect of glutamate antagonists was Ca2+ dependent and resulted from decreased cell division and increased cell death. Morphological alterations induced by glutamate antagonists in tumor cells consisted of reduced membrane ruffling and pseudopodial protrusions. Furthermore, glutamate antagonists decreased motility and invasive growth of tumor cells. These findings suggest anticancer potential of glutamate antagonists.

  9. Synthetic antibiofilm peptides.

    Science.gov (United States)

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  11. Peptide Vaccine Against Paracoccidioidomycosis.

    Science.gov (United States)

    Taborda, Carlos P; Travassos, Luiz R

    2017-01-01

    The chapter reviews methods utilized for the isolation and characterization of a promising immunogen candidate, aiming at a human vaccine against paracoccidioidomycosis. Peptide P10 carries a T-CD4+ epitope and was identified as an internal sequence of the major diagnostic antigen known as gp43 glycoprotein. It successfully treated massive intratracheal infections by virulent Paracoccidioides brasiliensis in combination with chemotherapy.An introduction about the systemic mycosis was found essential to understand the various options that were considered to design prophylactic and therapeutic vaccine protocols using peptide P10.

  12. Antagonism of antiviral and allogeneic activity of a human public CTL clonotype by a single altered peptide ligand: implications for allograft rejection

    Energy Technology Data Exchange (ETDEWEB)

    Ely, Lauren K.; Green, Katherine J.; Beddoe, Travis; Clements, Craig S.; Miles, John J.; Bottomley, Stephen P.; Zernich, Danielle; Kjer-Nielsen, Lars; Purcell, Anthony W.; McCluskey, James; Rossjohn, Jamie; Burrows, Scott R. (Monash)

    2010-06-30

    Alloreactive T lymphocytes are central mediators of graft-versus-host disease and allograft rejection. A public CTL clonotype with specificity for the alloantigens HLA-B*4402 and B*4405 is often expanded to large numbers in healthy HLA-B*0801{sup +} individuals, driven by cross-reactive stimulation with the common, persistent herpesvirus EBV. Since such alloreactive memory CTL expansions have the potential to influence transplantation outcome, altered peptide ligands (APLs) of the target HLA-B*0801-binding EBV peptide, FLRGRAYGL, were screened as specific antagonists for this immunodominant clonotype. One APL, FLRGRFYGL, exerted powerful antagonism of a prototypic T cell clone expressing this immunodominant TCR when costimulated with target cells presenting HLA-B*0801{sup FLRGRAYGL}. Significantly, this APL also reduced the lysis of allogeneic target cells expressing HLA-B*4402 by up to 99%. The affinities of the agonist and antagonist complexes for the public TCR, measured using solution and solid-phase assays, were 8 and 138 {micro}M, respectively. Surprisingly, the half-life of the agonist and antagonist complexes was similar, yet the association rate for the antagonist complex was significantly slower. These observations were further supported by structural studies that suggested a large conformational hurdle was required to ligate the immunodominant TCR to the HLA-B*0801 antagonist complex. By defining an antagonist APL against an immunodominant alloreactive TCR, these findings raise the prospect of exploiting such peptides to inhibit clinical alloreactivity, particularly against clonal T cell expansions that react with alloantigens.

  13. Hepcidin antagonists for potential treatments of disorders with hepcidin excess

    Directory of Open Access Journals (Sweden)

    Poli eMaura

    2014-04-01

    Full Text Available The discovery of hepcidin clarified the basic mechanism of the control of systemic iron homeostasis. Hepcidin is mainly produced by the liver as a propeptide and processed by furin into the mature active peptide. Hepcidin binds ferroportin, the only cellular iron exporter, causing the internalization and degradation of both. Thus hepcidin blocks iron export from the key cells for dietary iron absorption (enterocytes, recycling of haemoglobin iron (the macrophages and the release of storage iron from hepatocytes, resulting in the reduction of systemic iron availability. The BMP/HJV/SMAD pathway is the major regulator of hepcidin expression that responds to iron status. Also inflammation stimulates hepcidin via the IL6/STAT3 pathway with a support of an active BMP/HJV/SMAD pathway. In some pathological conditions hepcidin level is inadequately elevated and reduces iron availability in the body, resulting in anemia. These conditions occur in the genetic Iron Refractory Iron Deficiency Anemia (IRIDA and the common Anemia of Chronic Disease (ACD or Anemia of Inflammation. Currently, there is no definite treatment for ACD. Erythropoiesis stimulating agents and intravenous iron have been proposed in some cases but they are scarcely effective and may have adverse effects. Alternative approaches aimed to a pharmacological control of hepcidin expression have been attempted, targeting different regulatory steps. They include hepcidin sequestering agents (antibodies, anticalins and aptamers, inhibitors of BMP/SMAD or of IL6/STAT3 pathway or of hepcidin transduction (siRNA/shRNA or ferroportin stabilizers. In this review we summarized the biochemical interactions of the proteins involved in the BMP/HJV/SMAD pathway and its natural inhibitors, the murine and rat models with high hepcidin levels currently available and finally the progresses in the development of hepcidin antagonists, with particular attention to the role of heparins and heparin sulphate

  14. Combination decongestion therapy in hospitalized heart failure: loop diuretics, mineralocorticoid receptor antagonists and vasopressin antagonists.

    Science.gov (United States)

    Vaduganathan, Muthiah; Mentz, Robert J; Greene, Stephen J; Senni, Michele; Sato, Naoki; Nodari, Savina; Butler, Javed; Gheorghiade, Mihai

    2015-01-01

    Congestion is the most common reason for admissions and readmissions for heart failure (HF). The vast majority of hospitalized HF patients appear to respond readily to loop diuretics, but available data suggest that a significant proportion are being discharged with persistent evidence of congestion. Although novel therapies targeting congestion should continue to be developed, currently available agents may be utilized more optimally to facilitate complete decongestion. The combination of loop diuretics, natriuretic doses of mineralocorticoid receptor antagonists and vasopressin antagonists represents a regimen of currently available therapies that affects early and persistent decongestion, while limiting the associated risks of electrolyte disturbances, hemodynamic fluctuations, renal dysfunction and mortality.

  15. Investigation of orexin-2 selective receptor antagonists: Structural modifications resulting in dual orexin receptor antagonists.

    Science.gov (United States)

    Skudlarek, Jason W; DiMarco, Christina N; Babaoglu, Kerim; Roecker, Anthony J; Bruno, Joseph G; Pausch, Mark A; O'Brien, Julie A; Cabalu, Tamara D; Stevens, Joanne; Brunner, Joseph; Tannenbaum, Pamela L; Wuelfing, W Peter; Garson, Susan L; Fox, Steven V; Savitz, Alan T; Harrell, Charles M; Gotter, Anthony L; Winrow, Christopher J; Renger, John J; Kuduk, Scott D; Coleman, Paul J

    2017-03-15

    In an ongoing effort to explore the use of orexin receptor antagonists for the treatment of insomnia, dual orexin receptor antagonists (DORAs) were structurally modified, resulting in compounds selective for the OX 2 R subtype and culminating in the discovery of 23, a highly potent, OX 2 R-selective molecule that exhibited a promising in vivo profile. Further structural modification led to an unexpected restoration of OX 1 R antagonism. Herein, these changes are discussed and a rationale for selectivity based on computational modeling is proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Helokinestatin-7 peptides from the venoms of Heloderma lizards.

    Science.gov (United States)

    Ma, Chengbang; Wang, Hui; Wu, Yuxin; Zhou, Mei; Lowe, Gemma; Wang, Lei; Zhang, Yingqi; Chen, Tianbao; Shaw, Chris

    2012-06-01

    Helokinestatins 1-6 constitute a family of bradykinin antagonist peptides originally isolated from the venoms of the Gila Monster, Heloderma suspectum and the Mexican beaded lizard, Heloderma horridum. Here we report the identification, isolation and preliminary pharmacological characterization of two novel tridecapeptides, named helokinestatin-7S (FDDDSTELILEPR - 1550 Da) and helokinestatin-7H (FDDDSRKLILEPR - 1604 Da), whose primary structures were predicted from cDNAs cloned from venom libraries of respective Heloderma lizards. Computed molecular masses of putative helokinestatin-7 peptides were used as tools to locate these peptides in archived LC/MS fractions from respective venoms and sequences were confirmed by MS/MS fragmentation. A synthetic replicate of helokinestatin-7H was found to antagonize the relaxation effect of bradykinin on rat arterial smooth muscle but to have no measurable effects alone. In contrast, synthetic helokinestatin-7S was found to directly contract this preparation. Studies on related natural peptides with subtle differences in primary structure can provide the tools for structure/activity studies in pharmacological investigations directed toward unraveling the molecular basis of venom toxicity and for the evaluation of potential therapeutic leads. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Reduction of periodontal pathogens adhesion by antagonistic strains.

    Science.gov (United States)

    Van Hoogmoed, C G; Geertsema-Doornbusch, G I; Teughels, W; Quirynen, M; Busscher, H J; Van der Mei, H C

    2008-02-01

    Periodontitis results from a shift in the subgingival microflora into a more pathogenic direction with Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans considered as periodontopathogens. In many cases, treatment procures only a temporary shift towards a less pathogenic microflora. An alternative treatment could be the deliberate colonization of pockets with antagonistic microorganisms to control the adhesion of periodontopathogens. The aim of this study was to identify bacterial strains that reduce adhesion of periodontopathogens to surfaces. Streptococcus sanguinis, Streptococcus crista, Streptococcus salivarius, Streptococcus mitis, Actinomyces naeslundii, and Haemophilus parainfluenzae were evaluated as potential antagonists against P. gingivalis ATCC 33277, P. intermedia ATCC 49046, and A. actinomycetemcomitans ATCC 43718 as periodontopathogens. Adhesion of periodontopathogens to the bottom plate of a parallel plate flow chamber was studied in the absence (control) and the presence of pre-adhering antagonistic strains up to a surface coverage of 5%. The largest reduction caused by antagonistic strains was observed for P. gingivalis. All antagonistic strains except S. crista ATCC 49999 inhibited the adhesion of P. gingivalis by at least 1.6 cells per adhering antagonist, with the largest significant reduction observed for A. naeslundii ATCC 51655 (3.8 cells per adhering antagonist). Adhering antagonists had a minimal effect on the adhesion of A. actinomycetemcomitans ATCC 43718. Intermediate but significant reductions were perceived for P. intermedia, most notably caused by S. mitis BMS. The adhesion of P. gingivalis was inhibited best by antagonistic strains, while S. mitis BMS appeared to be the most successful antagonist.

  18. Development of second generation peptides modulating cellular adiponectin receptor responses

    Directory of Open Access Journals (Sweden)

    Laszlo eOtvos

    2014-10-01

    Full Text Available The adipose tissue participates in the regulation of energy homeostasis as an important endocrine organ that secretes a number of biologically active adipokines, including adiponectin. Recently we developed and characterized a first-in-class peptide-based adiponectin receptor agonist by using in vitro and in vivo models of glioblastoma and breast cancer (BC. In the current study, we further explored the effects of peptide ADP355 in additional cellular models and found that ADP355 inhibited chronic myeloid leukemia (CML cell proliferation and renal myofibroblast differentiation with mid-nanomolar IC50 values. According to molecular modeling calculations, ADP355 was remarkably flexible in the global minimum with a turn present in the middle of the peptide. Considering these structural features of ADP355 and the fact that adiponectin normally circulates as multimeric complexes, we developed and tested the activity of a linear branched dimer (ADP399. The dimer exhibited approximately 20-fold improved cellular activity inhibiting K562 CML and MCF-7 cell growth with high pM - low nM relative IC50 values. Biodistribution studies suggested superior tissue dissemination of both peptides after subcutaneous administration relative to intraperitoneal inoculation. After screening of a 397-member adiponectin active site library, a novel octapeptide (ADP400 was designed that counteracted 10-1000 nM ADP355- and ADP399-mediated effects on CML and BC cell growth at nanomolar concentrations. ADP400 induced mitogenic effects in MCF-7 BC cells perhaps due to antagonizing endogenous adiponectin actions or acting as an inverse agonist. While the linear dimer agonist ADP399 meets pharmacological criteria of a contemporary peptide drug lead, the peptide showing antagonist activity (ADP400 at similar concentrations will be an important target validation tool to study adiponectin functions.

  19. Molecular characterization of the gerbil C5a receptor and identification of a transmembrane domain V amino acid that is crucial for small molecule antagonist interaction.

    Science.gov (United States)

    Waters, Stephen M; Brodbeck, Robbin M; Steflik, Jeremy; Yu, Jianying; Baltazar, Carolyn; Peck, Amy E; Severance, Daniel; Zhang, Lu Yan; Currie, Kevin; Chenard, Bertrand L; Hutchison, Alan J; Maynard, George; Krause, James E

    2005-12-09

    Anaphylatoxin C5a is a potent inflammatory mediator associated with pathogenesis and progression of several inflammation-associated disorders. Small molecule C5a receptor (C5aR) antagonist development is hampered by species-specific receptor biology and the associated inability to use standard rat and mouse in vivo models. Gerbil is one rodent species reportedly responsive to small molecule C5aR antagonists with human C5aR affinity. We report the identification of the gerbil C5aR cDNA using a degenerate primer PCR cloning strategy. The nucleotide sequence revealed an open reading frame encoding a 347-amino acid protein. The cloned receptor (expressed in Sf9 cells) bound recombinant human C5a with nanomolar affinity. Alignment of the gerbil C5aR sequence with those from other species showed that a Trp residue in transmembrane domain V is the only transmembrane domain amino acid unique to small molecule C5aR antagonist-responsive species (i.e. gerbil, human, and non-human primate). Site-directed mutagenesis was used to generate human and mouse C5aRs with a residue exchange of this Trp residue. Mutation of Trp to Leu in human C5aR completely eliminated small molecule antagonist-receptor interaction. In contrast, mutation of Leu to Trp in mouse C5aR enabled small molecule antagonist-receptor interaction. This crucial Trp residue is located deeper within transmembrane domain V than residues reportedly involved in C5a- and cyclic peptide C5a antagonist-receptor interaction, suggesting a novel interaction site(s) for small molecule antagonists. These data provide insight into the basis for small molecule antagonist species selectivity and further define sites critical for C5aR activation and function.

  20. NCAM Mimetic Peptides: An Update

    DEFF Research Database (Denmark)

    Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    of combinatorial peptide libraries. The C3 and NBP10 peptides target the first Ig module whereas the ENFIN2 and ENFIN11 peptides target fibronectin type III (FN3) modules of NCAM. A number of NCAM mimetics can induce neurite outgrowth and exhibit neuroprotective and synaptic plasticity modulating properties...

  1. brain natriuretic peptide

    African Journals Online (AJOL)

    Background: Recently brain natriuretic peptide (BNP) level has been introduced as a screening test for congestive heart failure (CHF) in children. The current CHF assessment scores are not satisfactory as they use a large number of variables. Objective: To evaluate two CHF scores: a modified clinical score and an echo-.

  2. Brain Peptides and Psychopharmacology

    Science.gov (United States)

    Arehart-Treichel, Joan

    1976-01-01

    Proteins isolated from the brain and used as drugs can improve and apparently even transfer mental states and behavior. Much of the pioneering work and recent research with humans and animals is reviewed and crucial questions that are being posed about the psychologically active peptides are related. (BT)

  3. Distinct functions of opioid-related peptides and gastrin-releasing peptide in regulating itch and pain in the spinal cord of primates.

    Science.gov (United States)

    Lee, Heeseung; Ko, Mei-Chuan

    2015-06-29

    How neuropeptides in the primate spinal cord regulate itch and pain is largely unknown. Here we elucidate the sensory functions of spinal opioid-related peptides and gastrin-releasing peptide (GRP) in awake, behaving monkeys. Following intrathecal administration, β-endorphin (10-100 nmol) and GRP (1-10 nmol) dose-dependently elicit the same degree of robust itch scratching, which can be inhibited by mu-opioid peptide (MOP) receptor and GRP receptor (BB2) antagonists, respectively. Unlike β-endorphin, which produces itch and attenuates inflammatory pain, GRP only elicits itch without affecting pain. In contrast, enkephalins (100-1000 nmol) and nociceptin-orphanin FQ (3-30 nmol) only inhibit pain without eliciting itch. More intriguingly, dynorphin A(1-17) (10-100 nmol) dose-dependently attenuates both β-endorphin- and GRP-elicited robust scratching without affecting pain processing. The anti-itch effects of dynorphin A can be reversed by a kappa-opioid peptide (KOP) receptor antagonist nor-binaltorphimine. These nonhuman primate behavioral models with spinal delivery of ligands advance our understanding of distinct functions of neuropeptides for modulating itch and pain. In particular, we demonstrate causal links for itch-eliciting effects by β-endorphin-MOP receptor and GRP-BB2 receptor systems and itch-inhibiting effects by the dynorphin A-KOP receptor system. These studies will facilitate transforming discoveries of novel ligand-receptor systems into future therapies as antipruritics and/or analgesics in humans.

  4. [Biosynthesis of opioid peptides].

    Science.gov (United States)

    Rossier, J

    1988-01-01

    The endogenous opioid peptides all contain the enkephalin sequence Tyr-Gly-Gly-Phe-Met and Tyr-Gly-Gly-Phe-Leu at their aminoterminus. Three distinct families of these peptides (endorphins, enkephalins and dynorphins) are present in different neuronal pathways within the central nervous system. Molecular genetics have shown that these three families of opioid peptides are derived from three distinct precursors. Pro-opiomelanocortin gives rise to the endorphins, as well as adrenocorticotropic hormone (ACTH) and the melanotropic hormones (MSH's). [Met] enkephalin, [Leu] enkephalin and the related heptapeptide [Met] enkephalin-Arg6-Phe7 and octapeptide [Met] enkephalin-Arg6-Gly7-Leu8 are derived from proenkephalin. The third family is derived from prodynorphin and includes dynorphin A, dynorphin B (also known as rimorphin) and alpha- and beta-neo-endorphin. The structure of the genes coding for these precursors are similar, suggesting the possibility of one common ancestral gene. The most common scheme for enzymatic maturation of precursors proposes the action of a trypsin-like endopeptidase followed by a carboxypeptidase B-like exopeptidase. However, we have provided evidence that this combination of trypsin-like and carboxypeptidase B-like enzymes may not be the only mechanism for liberating enkephalin from low molecular weight enkephalin-containing peptides. Indeed, endo-oligopeptidase A, an enzyme, known to hydrolyze the Phe5-Ser6 bond of bradykinin and the Arg8-Arg9 bond of neurotensin, has been shown to produce, by a single cleavage, [Leu] enkephalin or [Met] enkephalin from small enkephalin-containing peptides, (Camargo et al., 1987, J. Neurochem. 48, 1258-1263).(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Biochemical functionalization of peptide nanotubes with phage displayed peptides

    Science.gov (United States)

    Swaminathan, Swathi; Cui, Yue

    2016-09-01

    The development of a general approach for the biochemical functionalization of peptide nanotubes (PNTs) could open up existing opportunities in both fundamental studies as well as a variety of applications. PNTs are spontaneously assembled organic nanostructures made from peptides. Phage display has emerged as a powerful approach for identifying selective peptide binding motifs. Here, we demonstrate for the first time the biochemical functionalization of PNTs via peptides identified from a phage display peptide library. The phage-displayed peptides are shown to recognize PNTs. These advances further allow for the development of bifunctional peptides for the capture of bacteria and the self-assembly of silver particles onto PNTs. We anticipate that these results could provide significant opportunities for using PNTs in both fundamental studies and practical applications, including sensors and biosensors nanoelectronics, energy storage devices, drug delivery, and tissue engineering.

  6. Neuropeptide FF analog RF9 is not an antagonist of NPFF receptor and decreases food intake in mice after its central and peripheral administration.

    Science.gov (United States)

    Maletínská, Lenka; Tichá, Anežka; Nagelová, Veronika; Spolcová, Andrea; Blechová, Miroslava; Elbert, Tomáš; Zelezná, Blanka

    2013-03-01

    Neuropeptide FF (NPFF) belongs to the RF-amide family of peptides bearing the identical C-terminal amino acid sequence (R-F-NH2). In addition to NPFF, prolactin-releasing peptide (PrRP), another RF-amide, binds to NPFF receptors with high affinity. A selective antagonist of PrRP has not yet been identified, but a selective antagonist of NPFF, 1-adamantanecarbonyl-RF-NH2 (RF9), was recently reported to antagonize the hyperalgesic effect of NPFF after central administration to mice. In the present study, RF9 competed with NPFF analog D-Y-L-(N-Me)-F-Q-P-Q-R-F-NH2 (1DMe) in binding to CHO-K1 cell membranes transfected with the human NPFF2 receptor. In rat pituitary RC-4B/C cells, where the expression of the NPFF2 receptor was proved by immunodetection, RF9 did not reverse the phosphorylation of MAPK/ERK1/2 induced by [Tyr(1)]NPFF. In vivo experiments with fasted mice confirmed that centrally injected [Tyr(1)]NPFF significantly lowered food intake. However, RF9, a putative NPFF2 antagonist, did not reverse the anorectic effect of [Tyr(1)]NPFF. Paradoxically, RF9 itself exhibited an anorectic effect in fasted mice not only after intracerebroventricular but also after subcutaneous administration. This finding casts doubt on claims that RF9 is an NPFF antagonist. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Diphenyl Purine Derivatives as Peripherally Selective Cannabinoid Receptor 1 Antagonists

    Science.gov (United States)

    Fulp, Alan; Bortoff, Katherine; Zhang, Yanan; Seltzman, Herbert; Mathews, James; Snyder, Rodney; Fennell, Tim; Maitra, Rangan

    2015-01-01

    Cannabinoid receptor 1 (CB1) antagonists are potentially useful for the treatment of several diseases. However, clinical development of several CB1 antagonists was halted due to central nervous system (CNS)-related side effects including depression and suicidal ideation in some users. Recently, studies have indicated that selective regulation of CB1 receptors in the periphery is a viable strategy for treating several important disorders. Past efforts to develop peripherally selective antagonists of CB1 have largely targeted rimonabant, an inverse agonist of CB1. Reported here are our efforts toward developing a peripherally selective CB1 antagonist based on the otenabant scaffold. Even though otenabant penetrates the CNS, it is unique among CB1 antagonists that have been clinically tested because it has properties that are normally associated with peripherally selective compounds. Our efforts have resulted in an orally absorbed compound that is a potent and selective CB1 antagonist with limited penetration into the CNS. PMID:23098108

  8. Hypocretin antagonists in insomnia treatment and beyond.

    Science.gov (United States)

    Ruoff, Chad; Cao, Michelle; Guilleminault, Christian

    2011-01-01

    Hypocretin neuropeptides have been shown to regulate transitions between wakefulness and sleep through stabilization of sleep promoting GABAergic and wake promoting cholinergic/monoaminergic neural pathways. Hypocretin also influences other physiologic processes such as metabolism, appetite, learning and memory, reward and addiction, and ventilatory drive. The discovery of hypocretin and its effect upon the sleep-wake cycle has led to the development of a new class of pharmacologic agents that antagonize the physiologic effects of hypocretin (i.e. hypocretin antagonists). Further investigation of these agents may lead to novel therapies for insomnia without the side-effect profile of currently available hypnotics (e.g. impaired cognition, confusional arousals, and motor balance difficulties). However, antagonizing a system that regulates the sleep-wake cycle while also influencing non-sleep physiologic processes may create an entirely different but equally concerning side-effect profile such as transient loss of muscle tone (i.e. cataplexy) and a dampened respiratory drive. In this review, we will discuss the discovery of hypocretin and its receptors, hypocretin and the sleep-wake cycle, hypocretin antagonists in the treatment of insomnia, and other implicated functions of the hypocretin system.

  9. Sexually antagonistic selection in human male homosexuality.

    Directory of Open Access Journals (Sweden)

    Andrea Camperio Ciani

    Full Text Available Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling 'Darwinian paradox'. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness, accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait.

  10. Sexually Antagonistic Selection in Human Male Homosexuality

    Science.gov (United States)

    Camperio Ciani, Andrea; Cermelli, Paolo; Zanzotto, Giovanni

    2008-01-01

    Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling ‘Darwinian paradox’. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait. PMID:18560521

  11. A CD36 synthetic peptide inhibits silica-induced lung fibrosis in the mice.

    Science.gov (United States)

    Wang, Xin; Lv, Lina; Chen, Ying; Chen, Jie

    2010-02-01

    Silicosis is a kind of pneumoconiosis caused by inhalation of silica dust, which is characterized by lung fibrosis. The biologically active form of transforming growth factor-beta1 (TGF-beta1) plays a key role in the development of lung fibrosis. CD36 is involved in the transformation of latent TGF-beta1 (L-TGF-beta1) to active TGF-beta1. The antagonistic effect of the synthetic peptide was analyzed by the administration of CD36 (93-110) synthetic peptide to the silicosis model of mice. The hydroxyproline content of the silica + CD36 (93-110) synthetic peptide group was significantly lower than that of the other experimental groups [silica and silica + CD36 (208-225) synthetic peptide groups] (p synthetic peptide group were less than those of the other experimental groups. The expressions of collagen I and III of the silica + CD36 (93-110) synthetic peptide group were significantly lower than those of the other experimental groups (p synthetic peptide reduced the tissue fibrotic pathologies and collagen accumulation in the silicosis model of mice, resulting in the decreased severity of silica-induced lung fibrosis.

  12. Improving the Fmoc Solid Phase Synthesis of the Cyclic Hexapeptide Complement C5a Antagonist, PMX205

    OpenAIRE

    deLisle Milton, R. C.; Milton, S. C.; Chamberlin, A. R.

    2011-01-01

    The anti-inflammatory drug, PMX205, is an antagonist of the C5a complement receptor and has been shown to be effective in rodent models of amyotrophic lateral sclerosis and Alzheimer’s disease. This cyclic hexapeptide (c[Arg-Trp-D-Cha-Pro-Orn]-Hca) has been reported to produce relatively low yields for both the linear peptide assembly and the cyclization reaction in solution and solid phase syntheses. During attempts to reproduce the solid phase methodology, a catastrophic loss of substitutio...

  13. Antibody Production with Synthetic Peptides.

    Science.gov (United States)

    Lee, Bao-Shiang; Huang, Jin-Sheng; Jayathilaka, Lasanthi P; Lee, Jenny; Gupta, Shalini

    2016-01-01

    Peptides (usually 10-20 amino acid residues in length) can be used as effectively as proteins in raising antibodies producing both polyclonal and monoclonal antibodies routinely with titers higher than 20,000. Peptide antigens do not function as immunogens unless they are conjugated to proteins. Production of high quality antipeptide antibodies is dependent upon peptide sequence selection, the success of peptide synthesis, peptide-carrier protein conjugation, the humoral immune response in the host animal, the adjuvant used, the peptide dose administered, the injection method, and the purification of the antibody. Peptide sequence selection is probably the most critical step in the production of antipeptide antibodies. Although the process for designing peptide antigens is not exact, several guidelines and computational B-cell epitope prediction methods can help maximize the likelihood of producing antipeptide antibodies that recognize the protein. Antibodies raised by peptides have become essential tools in life science research. Virtually all phospho-specific antibodies are now produced using phosphopeptides as antigens. Typically, 5-20 mg of peptide is enough for antipeptide antibody production. It takes 3 months to produce a polyclonal antipeptide antibody in rabbits that yields ~100 mL of serum which corresponds to ~8-10 mg of the specific antibody after affinity purification using a peptide column.

  14. Design of a novel cyclotide-based CXCR4 antagonist with anti-human immunodeficiency virus (HIV)-1 activity

    Science.gov (United States)

    Aboye, Teshome L.; Ha, Helen; Majumber, Subhabrata; Christ, Frauke; Debyser, Zeger; Shekhtman, Alexander; Neamati, Nouri; Camarero, Julio A.

    2012-01-01

    Herein, we report for the first time the design and synthesis of a novel cyclotide able to efficiently inhibit HIV-1 viral replication by selectively targeting cytokine receptor CXCR4. This was accomplished by grafting a series of topologically modified CVX15 based peptides onto the loop 6 of cyclotide MCoTI-I. The most active compound produced in this study was a potent CXCR4 antagonist (EC50 ≈ 20 nM) and an efficient HIV-1 cell-entry blocker (EC50 ≈ 2 nM). This cyclotide also showed high stability in human serum thereby providing a promising lead compound for the design of a novel type of peptide-based anti-cancer and anti-HIV-1 therapeutics. PMID:23151033

  15. US -endorphin-(1-27) is a naturally occurring antagonist to etorphine-induced analgesia

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, P.; Li, C.H.

    1985-05-01

    The potent opioid peptide US -endorphin is found in the brain and pituitary with two related fragments, US -endorphin-(1-27) and US -endorphin-(1-26). The fragments, retain substantial opioid-receptor binding activity but are virtually inactive analgesically. US -Endorphin-(1-27) inhibits US -endorphin-induced and etorphine-induced analgesia when coinjected intracerebroventricularly into mice. Antagonism by competition at the same site(s) is suggested from parallel shifts of the dose-response curves of etorphine or US -endorphin in the presence of US -endorphin-(1-27). Its potency is 4-5 times greater than that of the opiate antagonist naloxone. US -Endorphin-(1-26) does not antagonize the antinociceptive action of etorphine or US -endorphin in doses up to 500 pmol per animal.

  16. Antimicrobial Peptides (AMPs

    Directory of Open Access Journals (Sweden)

    Mehrzad Sadredinamin

    2016-04-01

    Full Text Available Antimicrobial peptides (AMPs are extensive group of molecules that produced by variety tissues of invertebrate, plants, and animal species which play an important role in their immunity response. AMPs have different classifications such as; biosynthetic machines, biological sources, biological functions, molecular properties, covalent bonding patterns, three dimensional structures, and molecular targets.These molecules have multidimensional properties including antimicrobial activity, antiviral activity, antifungal activity, anti-parasite activity, biofilm control, antitumor activity, mitogens activity and linking innate to adaptive immunity that making them promising agents for therapeutic drugs. In spite of this advantage of AMPs, their clinical developments have some limitation for commercial development. But some of AMPs are under clinical trials for the therapeutic purpose such as diabetic foot ulcers, different bacterial infections and tissue damage. In this review, we emphasized on the source, structure, multidimensional properties, limitation and therapeutic applications of various antimicrobial peptides.

  17. Radiolabelled peptides vs. nanoparticle-peptide complexes for medical applications

    International Nuclear Information System (INIS)

    Ferro F, G.

    2007-01-01

    Full text: The principle that peptide receptors can be used successfully for in vivo targeting of human cancers has been provided and the peptide-receptor radionuclide therapy for malignant tumors is a real treatment option. Targeted entry into cells is an increasingly important area of research. The diagnoses and treatment of disease by novel methods would be enhanced greatly by the efficient transport of materials to living cell nuclei. Membrane-trans locating peptides complexed to nanoparticles are small enough (30 nm) to cross the nuclear membrane and to enter the cell via receptor-mediated endocytosis, emerging as a new type of pharmaceuticals. Pharmacokinetic properties and molecular specificity of iron or gold nanoparticle-peptide complexes that do not induce biological toxicity is a topic of world interest in current and future medical investigations. Some perspectives and achievements on the preparation, pharmacokinetics and dosimetry of radiolabelled peptides versus nanoparticle-peptide complexes for medical applications are presented. (Author)

  18. The Attractiveness of Opposites: Agonists and Antagonists.

    LENUS (Irish Health Repository)

    O'Brien, Tony

    2015-02-02

    ABSTRACT Opioid-induced bowel dysfunction, of which constipation is the most common aspect, is a major limiting factor in the use of opioids for pain management. The availability of an oral, long-acting formulation of oxycodone and naloxone represents a highly significant development in pain management. The combination of an opioid analgesic with an opioid antagonist offers reliable pain control with a significant reduction in the burden of opioid-induced constipation. This report is adapted from paineurope 2014; Issue 3, ©Haymarket Medical Publications Ltd, and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, LTD and is distributed free of charge to healthcare professionals in Europe. Archival issues can be accessed via the website: http:\\/\\/www.paineurope.com at which European health professionals can register online to receive copies of the quarterly publication.

  19. Antiallergic effects of H1-receptor antagonists.

    Science.gov (United States)

    Baroody, F M; Naclerio, R M

    2000-01-01

    The primary mechanism of antihistamine action in the treatment of allergic diseases is believed to be competitive antagonism of histamine binding to cellular receptors (specifically, the H1-receptors), which are present on nerve endings, smooth muscles, and glandular cells. This notion is supported by the fact that structurally unrelated drugs antagonize the H1-receptor and provide clinical benefit. However, H1-receptor antagonism may not be their sole mechanism of action in treating allergic rhinitis. On the basis of in vitro and animal experiments, drugs classified as H1-receptor antagonists have long been recognized to have additional pharmacological properties. Most first-generation H1-antihistamines have anticholinergic, sedative, local anaesthetic, and anti-5-HT effects, which might favourably affect the symptoms of the allergic response but also contribute to side-effects. These additional properties are not uniformly distributed among drugs classified as H1-receptor antagonists. Azatadine, for example, inhibits in vitro IgE-mediated histamine and leukotriene (LT) release from mast cells and basophils. In human challenge models, terfenadine, azatadine, and loratadine reduce IgE-mediated histamine release. Cetirizine reduces eosinophilic infiltration at the site of antigen challenge in the skin, but not the nose. In a nasal antigen challenge model, cetirizine pretreatment did not affect the levels of histamine and prostaglandin D2 recovered in postchallenge lavages, whereas the levels of albumin, N-tosyl-L-arginine methyl ester (TAME) esterase activity, and LTs were reduced. Terfenadine, cetirizine, and loratadine blocked allergen-induced hyperresponsiveness to methacholine. In view of the complexity of the pathophysiology of allergy, a number of H1 antagonists with additional properties are currently under development for allergic diseases. Mizolastine, a new H1-receptor antagonist, has been shown to have additional actions that should help reduce the

  20. Calcium antagonists and the diabetic hypertensive patient

    DEFF Research Database (Denmark)

    Parving, H H; Rossing, P

    1993-01-01

    reduces albuminuria, delays the progression of nephropathy, and postpones renal insufficiency in diabetic nephropathy. Calcium antagonists and angiotensin converting enzyme inhibitors induce an acute increase in the glomerular filtration rate, renal plasma flow, and renal sodium excretion......Roughly 40% of all diabetic patients, whether insulin dependent or not, develop persistent albuminuria (over 300 mg/24 hr), a decrease in the glomerular filtration rate, and elevated blood pressure, ie, diabetic nephropathy. Diabetic nephropathy is the single most important cause of end stage renal...... disease in the Western world, and accounts for over a quarter of all end stage renal disease. It also is a major cause of the increased morbidity and mortality seen in diabetic patients; for example, the cost of end stage renal care in the United States currently exceeds +1.8 billion per year for diabetic...

  1. Assay method for organic calcium antagonist drugs and a kit for such an assay

    International Nuclear Information System (INIS)

    Snyder, S. H.; Gould, R. J.

    1985-01-01

    A method for measuring the level of organic calcium antagonist drug in a body fluid comprises preparing a mixture of a radioactive calcium antagonist drug, a body fluid containing a calcium antagonist drug and a calcium antagonist receptor material, measuring the radioactivity of the radioactive calcium antagonist drug bound to said calcium antagonist receptor material and deriving the concentration of the calcium antagonist drug in the body fluid from a standard curve indicating the concentration of calcium antagonist drug versus inhibition of binding of said radioactive calcium antagonist drug to said receptor sites caused by the calcium antagonist drug in said body fluid. A kit for measuring the level of an organic calcium drug comprises a receptacle containing a radioactive calcium antagonist drug, a calcium antagonist receptor material and a standard amount of a nonradioactive calcium antagonist drug

  2. Antagonistic activity of marine sponges associated Actinobacteria

    Directory of Open Access Journals (Sweden)

    Selvakumar Dharmaraj

    2016-06-01

    Full Text Available Objective: To focus on the isolation and preliminary characterization of marine sponges associated Actinobacteria particularly Streptomyces species and also their antagonistic activities against bacterial and fungal pathogens. Methods: The sponges were collected from Kovalam and Vizhinjam port of south-west coast of Kerala, India. Isolation of strains was carried out from sponge extracts using international Streptomyces project media. For preliminary identification of the strains, morphological (mycelial colouration, soluble pigments, melanoid pigmentation, spore morphology, nutritional uptake (carbon utilisation, amonoacids influence, sodium chloride tolerance, physiological (pH, temperature and chemotaxonomical characterization were done. Antimicrobial studies were also carried out for the selected strains. Results: With the help of the spicule structures, the collected marine sponges were identified as Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Nearly 94 strains were primarily isolated from these sponges and further they were sub-cultured using international Streptomyces project media. The strains exhibited different mycelial colouration (aerial and substrate, soluble and melanoid pigmentations. The strains possessed three types of sporophore morphology namely rectus flexibilis, spiral and retinaculiaperti. Among the 94 isolates, seven exhibited antibacterial and antifungal activities with maximal zone of inhibition of 30 mm. The nutritional, physiological and chemotaxonomical characteristic study helped in the conventional identification of the seven strains and they all suggest that the strains to be grouped under the genus Streptomyces. Conclusions: The present study clearly helps in the preliminary identification of the isolates associated with marine sponges. Antagonistic activities prove the production of antimicrobial metabolites against the pathogens. Marine sponges associated Streptomyces are

  3. Preliminary Molecular Dynamic Simulations of the Estrogen Receptor Alpha Ligand Binding Domain from Antagonist to Apo

    Directory of Open Access Journals (Sweden)

    Adrian E. Roitberg

    2008-06-01

    Full Text Available Estrogen receptors (ER are known as nuclear receptors. They exist in the cytoplasm of human cells and serves as a DNA binding transcription factor that regulates gene expression. However the estrogen receptor also has additional functions independent of DNA binding. The human estrogen receptor comes in two forms, alpha and beta. This work focuses on the alpha form of the estrogen receptor. The ERα is found in breast cancer cells, ovarian stroma cells, endometrium, and the hypothalamus. It has been suggested that exposure to DDE, a metabolite of DDT, and other pesticides causes conformational changes in the estrogen receptor. Before examining these factors, this work examines the protein unfolding from the antagonist form found in the 3ERT PDB crystal structure. The 3ERT PDB crystal structure has the estrogen receptor bound to the cancer drug 4-hydroxytamoxifen. The 4-hydroxytamoxifen ligand was extracted before the simulation, resulting in new conformational freedom due to absence of van der Waals contacts between the ligand and the receptor. The conformational changes that result expose the binding clef of the co peptide beside Helix 12 of the receptor forming an apo conformation. Two key conformations in the loops at either end of the H12 are produced resulting in the antagonist to apo conformation transformation. The results were produced over a 42ns Molecular Dynamics simulation using the AMBER FF99SB force field.

  4. GLP-1 receptor antagonist as a potential probe for pancreatic β-cell imaging

    International Nuclear Information System (INIS)

    Mukai, Eri; Toyoda, Kentaro; Kimura, Hiroyuki; Kawashima, Hidekazu; Fujimoto, Hiroyuki; Ueda, Masashi; Temma, Takashi; Hirao, Konomu; Nagakawa, Kenji; Saji, Hideo; Inagaki, Nobuya

    2009-01-01

    We examined exendin(9-39), an antagonist of glucagon-like peptide-1 (GLP-1) receptor (GLP-1R), as a potential probe for imaging of pancreatic β-cells. To evaluate in vitro receptor specificity, binding assay was performed using dispersed mouse islet cells. Binding assay showed competitive inhibition of [ 125 I]BH-exendin(9-39) binding by non-radioactive exendin(9-39). To assess in vivo selectivity, the biodistribution was evaluated by intravenous administration of [ 125 I]BH-exendin(9-39) to mice. Radioactivity of harvested pancreas reached highest levels at 60 and 120 min among organs examined except lung. Pre-administration of excess non-radioactive exendin(9-39) remarkably and specifically blocked the radioactivity of pancreas. After [ 125 I]BH-exendin(9-39) injection into transgenic mice with pancreatic β-cells expressing GFP, fluorescent and radioactive signals of sections of pancreas were evaluated with an image analyzer. Imaging analysis showed that the fluorescent GFP signals and the radioactive signals were correspondingly located. Thus, the GLP-1R antagonist exendin(9-39) may serve as a useful probe for pancreatic β-cell imaging.

  5. Peptide-enhanced oral delivery of therapeutic peptides and proteins

    DEFF Research Database (Denmark)

    Kristensen, Mie; Foged, Camilla; Berthelsen, Jens

    2013-01-01

    Systemic therapy upon oral delivery of biologics, such as peptide and protein drugs is limited due to their large molecular size, their low enzymatic stability and their inability to cross the intestinal epithelium. Ways to overcome the epithelial barrier include the use of peptide-based excipients...... throughout the gastrointestinal (GI) tract, chemical stability is an inherent challenge when employing amino acid-based excipients for oral delivery, and multiple approaches have been investigated to improve this. The exact mechanisms of transepithelial translocation are discussed, and it is believed...... for oral delivery of peptide and protein drugs highlighting recent studies and the most promising compounds from these classes of peptide excipients....

  6. Effect of a Hypocretin/Orexin Antagonist on Neurocognitive Performance

    Science.gov (United States)

    2013-12-18

    Effectiveness Directorate, Biosciences and Protection Division, Warfighter Fatigue Countermeasures Branch. 35. Golden, C.J. (1978). Stroop Color and Word Test: A...0080 TITLE: Effect of a Hypocretin/Orexin Antagonist on Neurocognitive Performance PRINCIPAL INVESTIGATOR: Dr. Thomas Neylan...31August2013 4. TITLE AND SUBTITLE Effect of a Hypocretin/Orexin Antagonist on Neurocognitive Performance 5a. CONTRACT NUMBER W81XWH

  7. Using waste of Tofu production improved antagonistic activities of a ...

    African Journals Online (AJOL)

    Mrs. Hoa

    2012-10-04

    Oct 4, 2012 ... screened for their antagonistic activity against 10 races of Xoo causing rice bacterial blight disease. Three actinomycete strains ... antagonistic activity of VN10-A-44 against the Xoo pathogen and to make use of tofu waste for large- ..... vitamins and some essential amino acids which are very important for ...

  8. Thrombin-receptor antagonist vorapaxar in acute coronary syndromes

    DEFF Research Database (Denmark)

    Tricoci, Pierluigi; Huang, Zhen; Held, Claes

    2012-01-01

    Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation.......Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation....

  9. Evaluation of antagonistic fungi against charcoal rot of sunflower ...

    African Journals Online (AJOL)

    In vitro, sensitivity of Macrophomina phaseolina (Tassi) Goid determined through inhibition zone technique to various antagonistic fungi viz., Aspergillus niger, Aspergillus flavus, Trichoderma viride, Trichoderma harzianum and Penicillium capsulatum amended into PDA medium. All the antagonists reduced the colony ...

  10. Calcium antagonists for ischemic stroke: a systematic review

    NARCIS (Netherlands)

    Horn, J.; Limburg, M.

    2001-01-01

    BACKGROUND AND PURPOSE: Stroke is a common disease, and many trials with calcium antagonists as possible neuroprotective agents have been conducted. The aim of this review is to determine whether calcium antagonists reduce the risk of death or dependency after acute ischemic stroke. METHODS: Acute

  11. Antagonistic and Bargaining Games in Optimal Marketing Decisions

    Science.gov (United States)

    Lipovetsky, S.

    2007-01-01

    Game theory approaches to find optimal marketing decisions are considered. Antagonistic games with and without complete information, and non-antagonistic games techniques are applied to paired comparison, ranking, or rating data for a firm and its competitors in the market. Mix strategy, equilibrium in bi-matrix games, bargaining models with…

  12. Biochemical and pharmacological characterization of three opioid-nociceptin hybrid peptide ligands reveals substantially differing modes of their actions.

    Science.gov (United States)

    Erdei, Anna I; Borbély, Adina; Magyar, Anna; Taricska, Nóra; Perczel, András; Zsíros, Ottó; Garab, Győző; Szűcs, Edina; Ötvös, Ferenc; Zádor, Ferenc; Balogh, Mihály; Al-Khrasani, Mahmoud; Benyhe, Sándor

    2018-01-01

    In an attempt to design opioid-nociceptin hybrid peptides, three novel bivalent ligands, H-YGGFGGGRYYRIK-NH 2 , H-YGGFRYYRIK-NH 2 and Ac-RYYRIKGGGYGGFL-OH were synthesized and studied by biochemical, pharmacological, biophysical and molecular modelling tools. These chimeric molecules consist of YGGF sequence, a crucial motif in the N-terminus of natural opioid peptides, and Ac-RYYRIK-NH 2, which was isolated from a combinatorial peptide library as an antagonist or partial agonist that inhibits the biological activity of the endogenously occurring heptadecapeptide nociceptin. Solution structures for the peptides were studied by analysing their circular dichroism spectra. Receptor binding affinities were measured by equilibrium competition experiments using four highly selective radioligands. G-protein activating properties of the multitarget peptides were estimated in [ 35 S]GTPγS binding tests. The three compounds were also measured in electrically stimulated mouse vas deferens (MVD) bioassay. H-YGGFGGGRYYRIK-NH 2 (BA55), carrying N-terminal opioid and C-terminal nociceptin-like sequences interconnected with GGG tripeptide spacer displayed a tendency of having either unordered or β-sheet structures, was moderately potent in MVD and possessed a NOP/KOP receptor preference. A similar peptide without spacer H-YGGFRYYRIK-NH 2 (BA62) exhibited the weakest effect in MVD, more α-helical periodicity was present in its structure and it exhibited the most efficacious agonist actions in the G-protein stimulation assays. The third hybrid peptide Ac-RYYRIKGGGYGGFL-OH (BA61) unexpectedly displayed opioid receptor affinities, because the opioid message motif is hidden within the C-terminus. The designed chimeric peptide ligands presented in this study accommodate well into a group of multitarget opioid compounds that include opioid-non-opioid peptide dimer analogues, dual non-peptide dimers and mixed peptide- non-peptide bifunctional ligands. Copyright © 2017 Elsevier Inc

  13. Interaction between Antagonist of Cannabinoid Receptor and Antagonist of Adrenergic Receptor on Anxiety in Male Rat

    Directory of Open Access Journals (Sweden)

    Alireza Komaki

    2014-07-01

    Full Text Available Introduction: Anxiety is among the most common and treatable mental disorders. Adrenergic and cannabinoid systems have an important role in the neurobiology of anxiety. The elevated plus-maze (EPM has broadly been used to investigate anxiolytic and anxiogenic compounds. The present study investigated the effects of intraperitoneal (IP injection of cannabinoid CB1 receptor antagonist (AM251 in the presence of alpha-1 adrenergic antagonist (Prazosin on rat behavior in the EPM. Methods: In this study, the data were obtained from male Wistar rat, which weighing 200- 250 g. Animal behavior in EPM were videotaped and saved in computer for 10 min after IP injection of saline, AM251 (0.3 mg/kg, Prazosin (0.3 mg/kg and AM251 + Prazosin, subsequently scored for conventional indices of anxiety. During the test period, the number of open and closed arms entries, the percentage of entries into the open arms of the EPM, and the spent time in open and closed arms were recorded. Diazepam was considered as a positive control drug with anxiolytic effect (0.3, 0.6, 1.2 mg/kg. Results: Diazepam increased the number of open arm entries and the percentage of spent time on the open arms. IP injection of AM251 before EPM trial decreased open arms exploration and open arm entry. Whereas, Prazosin increased open arms exploration and open arm entry. This study showed that both substances in simultaneous injection have conflicting effects on the responses of each of these two compounds in a single injection. Discussion: Injection of CB1 receptor antagonist may have an anxiogenic profile in rat, whereas adrenergic antagonist has an anxiolytic effect. Further investigations are essential for better understanding of anxiolytic and anxiogenic properties and neurobiological mechanisms of action and probable interactions of the two systems.

  14. Peptide Signals Encode Protein Localization▿

    OpenAIRE

    Russell, Jay H.; Keiler, Kenneth C.

    2007-01-01

    Many bacterial proteins are localized to precise intracellular locations, but in most cases the mechanism for encoding localization information is not known. Screening libraries of peptides fused to green fluorescent protein identified sequences that directed the protein to helical structures or to midcell. These peptides indicate that protein localization can be encoded in 20-amino-acid peptides instead of complex protein-protein interactions and raise the possibility that the location of a ...

  15. The Equine PeptideAtlas

    DEFF Research Database (Denmark)

    Bundgaard, Louise; Jacobsen, Stine; Sorensen, Mette A.

    2014-01-01

    Equine PeptideAtlas encompassing high-resolution tandem MS analyses of 51 samples representing a selection of equine tissues and body fluids from healthy and diseased animals. The raw data were processed through the Trans-Proteomic Pipeline to yield high quality identification of proteins and peptides...... analyses, and emphasizes the value of the Equine PeptideAtlas as a resource for the design of targeted quantitative proteomic studies....

  16. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    The role of proteins as very effective immunogens for the generation of antibodies is indisputable. Nevertheless, cases in which protein usage for antibody production is not feasible or convenient compelled the creation of a powerful alternative consisting of synthetic peptides. Synthetic peptides...... can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery...

  17. The metabolite generated by dipeptidyl-peptidase 4 metabolism of glucagon-like peptide-1 has no influence on plasma glucose levels in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Zander, M; Madsbad, S; Deacon, C F

    2006-01-01

    AIM/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) is metabolised by the enzyme dipeptidyl-peptidase 4 (DPP-4), generating a metabolite with potential antagonistic properties. This study was conducted to evaluate the effect of that metabolite on plasma glucose levels in patients with type 2 diabetes...

  18. One Hundred Years of Peptide Chemistry

    Indian Academy of Sciences (India)

    thus a chiral center. Today, 20 amino acids are known as genetically encoded as building blocks of peptides and proteins. Almost all of them present in peptides have L-configura- tion. D-amino acids have been found only in small peptides of bacterial cell walls, peptide antibiotics and peptides in South American frog skin.

  19. Localization of receptors for bombesin-like peptides in the rat brain

    International Nuclear Information System (INIS)

    Moody, T.W.; Getz, R.; O'Donohue, T.L.; Rosenstein, J.M.

    1988-01-01

    BN-like peptides and receptors are present in discrete areas of the mammalian brain. By radioimmunoassay, endogenous BN/GRP, neuromedin B, and ranatensin-like peptides are present in the rat brain. High-to-moderate concentrations of BN/GRP are present in the rat hypothalamus and thalamus, whereas moderate-to-high densities of neuromedin B and ranatensin-like peptides are present in the olfactory bulb and hippocampus, as well as in the hypothalamus and thalamus. While the distribution of neuromedin B and ranatensin-like peptides appears similar, it is distinct from that of BN/GRP. When released from CNS neurons, these peptides may interact with receptors for BN-like peptides. BN, GRP, ranatensin, and neuromedin B inhibit specific [ 125 I-Tyr4]BN binding with high affinity. By use of in vitro autoradiographic techniques to detect binding of [ 125 I-Tyr4]BN to receptors for BN-like peptides, high grain densities were found in the olfactory bulb and tubercle, the nucleus accumbens, the suprachiasmatic and paraventricular nucleus of the hypothalamus, the central medial and paraventricular thalamic nuclei, the hippocampus, the dentate gyrus, and the amygdala of the rat brain. Some of these receptors may be biologically active and mediate the biological effects of BN-like peptides. For example, when BN is directly injected into the nucleus accumbens, pronounced grooming results and the effects caused by BN are reversed by spantide and [D-Phe12]BN. Thus, the putative BN receptor antagonists may serve as useful agents to investigate the biological significance of BN-like peptides in the CNS

  20. Current position of 5HT3 antagonists and the additional value of NK1 antagonists; a new class of antiemetics

    NARCIS (Netherlands)

    R. de Wit (Ronald)

    2003-01-01

    textabstractThe advent of the 5HT3 receptor antagonists (5HT3 antagonists) in the 1990s and the combination with dexamethasone has resulted in acute emesis protection in 70% of patients receiving highly emetogenic chemotherapy. Despite complete protection in the acute phase, however, 40% of patients

  1. Head-to-tail macrocyclization of cysteine-free peptides using an o-aminoanilide linker.

    Science.gov (United States)

    Ohara, Takumi; Kaneda, Masato; Saito, Tomo; Fujii, Nobutaka; Ohno, Hiroaki; Oishi, Shinya

    2018-05-01

    A head-to-tail macrocyclization protocol for the preparation of cysteine-free cyclic peptides was investigated. The o-aminoanilide linker constructed in the peptide sequence by a standard Fmoc-based peptide synthesis procedure was subjected to nitrite-mediated activation under acidic conditions toward N-acyl benzotriazole as the active ester species. The subsequent cyclization smoothly proceeded by neutralization in the presence of additives such as 1-hydroxybenzotriazole (HOBt) and 1-hydroxy-7-azabenzotriazole (HOAt) to afford the expected cyclic pentapeptide, a CXCR4 antagonist. The cyclization efficiencies were dependent on the precursor open-chain sequence. The application of this step-wise activation-cyclization protocol to microflow reaction systems is also described. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Analysis of binding centers in nicotinic receptors with the aid of synthetic peptides.

    Science.gov (United States)

    Kasheverov, I E; Kryukova, E V; Kudryavtsev, D S; Ivanov, I A; Egorova, N V; Zhmak, M N; Spirova, E N; Shelukhina, I V; Odinokov, A V; Alfimov, M V; Tsetlin, V I

    2016-09-01

    We studies the receptor-binding specificity of the synthetic peptide HAP (High Affinity Peptide) and its analogues, which are regarded as a model of the orthosteric site nicotinic acetylcholine receptors (nAChR). Using radioligand analysis, electrophysiology tests, and calcium imaging, we assessed the ability of HAP to interact with nAChR antagonists: long α-neurotoxins and α-conotoxins. A high affinity of HAP for α-bungarotoxin and the absence of its interaction with α-cobratoxin and α-conotoxins was found. The synthesized analogues of HAP in general retained the properties of the original peptide. Thus, HAP cannot be a model of a ligand-binding site.

  3. RFamide Peptides: Structure, Function, Mechanisms and Pharmaceutical Potential

    Directory of Open Access Journals (Sweden)

    Maria Findeisen

    2011-09-01

    Full Text Available Different neuropeptides, all containing a common carboxy-terminal RFamide sequence, have been characterized as ligands of the RFamide peptide receptor family. Currently, five subgroups have been characterized with respect to their N-terminal sequence and hence cover a wide pattern of biological functions, like important neuroendocrine, behavioral, sensory and automatic functions. The RFamide peptide receptor family represents a multiligand/multireceptor system, as many ligands are recognized by several GPCR subtypes within one family. Multireceptor systems are often susceptible to cross-reactions, as their numerous ligands are frequently closely related. In this review we focus on recent results in the field of structure-activity studies as well as mutational exploration of crucial positions within this GPCR system. The review summarizes the reported peptide analogs and recently developed small molecule ligands (agonists and antagonists to highlight the current understanding of the pharmacophoric elements, required for affinity and activity at the receptor family. Furthermore, we address the biological functions of the ligands and give an overview on their involvement in physiological processes. We provide insights in the knowledge for the design of highly selective ligands for single receptor subtypes to minimize cross-talk and to eliminate effects from interactions within the GPCR system. This will support the drug development of members of the RFamide family.

  4. Identification of an endogenous alpha-adrenergic receptor antagonist: studies on its possible role in endocrine and cardiovascular function

    International Nuclear Information System (INIS)

    Dunbar, J.C.; Wider, M.; House, F.; Campbell, R.

    1986-01-01

    The concept of α and β adrenergic receptors that are regulated by epinephrine or norepinephrine (NE) is well established. The reported receptor antagonists have been synthetic. A peptide extracted from the duodenal mucosa with α-2 antagonist properties has been identified. It specifically inhibits 3 H-yohimbine binding (α-2) but not 3 H dihydroalprenolol (β) binding in whole brain membranes. Partially purified preparations of the alpha receptor binding inhibitor (ABI) were tested for endocrine pancreatic and cardiovascular effects. When isolated islets were incubated in the presence of ABI with and without NE, ABI along did not alter insulin secretion but completely reversed the NE suppression of glucose stimulated insulin release. Glucagon secretion by these same islets was enhanced by ABI and augmented the stimulatory effect of NE. Intravenous (I.V.) infusion of ABI increased serum insulin in the presence of NE and decreased the serum glucose response to a glucose load. Infusion of ABI into the 4th ventricle, or I.V. resulted in a decrease (50-60%) in systolic and diastolic blood pressure as well as a decrease (10-20%) in heart rate. From these studies the authors conclude that a duodenal peptide with the capacity to inhibit α-2 agonist binding may play a role in endocrine and cardiovascular functions

  5. 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.

  6. Peptide Vaccines for Cancer

    Directory of Open Access Journals (Sweden)

    Kono K

    2013-10-01

    Full Text Available Background: In general, the preferable characteristic of the target molecules for development of cancer vaccines are high immunogenicity, very common expression in cancer cells, specific expression in cancer cells and essential molecules for cell survival (to avoid loss of expression. We previously reported that three novel HLA-A24-restricted immunodominant peptides, which were derived from three different oncoantigens, TTK, LY6K, and IMP-3,were promising targets for cancer vaccination for esophageal squamous cell carcinoma (ESCCpatients. Then, we had performed a phase I clinical trial using three HLA-A24-binding peptides and the results had been shown to be promising for ESCC. Therefore, we further performed a multicenter, non-randomized phase II clinical trial. Patients and Methods: Sixty ESCC patients were enrolled to evaluate OS, PFS, immunological response employing ELISPOT and pentamer assays. Each of the three peptides was administered with IFA weekly. All patients received the vaccination without knowing an HLA-A type, and the HLA types were key-opened at the analysis point. Hence, the endpoints were set to evaluate differences between HLA-A*2402-positive (24(+ and -negative (24(- groups. Results: The OS in the 24 (+ group (n=35 tended to be better than that in the 24(- group (n=25 (MST 4.6 vs. 2.6 month, respectively, p = 0.121, although the difference was not statistically significant. However, the PFS in the 24(+ group was significantly better than that in the 24(- group (p = 0.032. In the 24(+ group, ELISPOT assay indicated that the LY6K-, TTK-, and IMP3-specific CTL responses were observed after the vaccination in 63%, 45%, and 60% of the 24(+ group, respectively. The patients having LY6K-, TTK-, and IMP3-specific CTL responses revealed the better OS than those not having CTL induction, respectively. The patients showing the CTL induction for multiple peptides have better clinical responses. Conclusion: The immune response induced

  7. In vitro and in vivo pharmacological characterization of Pronetupitant, a prodrug of the neurokinin 1 receptor antagonist Netupitant.

    Science.gov (United States)

    Ruzza, Chiara; Rizzi, Anna; Malfacini, Davide; Molinari, Stefano; Giuliano, Claudio; Lovati, Emanuela; Pietra, Claudio; Calo', Girolamo

    2015-07-01

    The aim of the present study was to investigate the pharmacological activity of Pronetupitant, a novel compound designed to act as prodrug of the NK1 antagonist Netupitant. In receptor binding experiments Pronetupitant displayed high selectivity for the NK1 receptor. In a calcium mobilization assay performed on CHONK1 cells Pronetupitant (100 nM, 15 min preincubation) behaved as an NK1 antagonist more potent than Netupitant (pK(B) 8.72 and 7.54, respectively). In the guinea pig ileum bioassay Pronetupitant antagonized the contractile effect of SP showing a similar potency as Netupitant (pK(B)≈9). Similar results were obtained with 5 min preincubation time while at 2 min only Pronetupitant produced significant effects. In vivo in mice the intrathecal injection of 0.1 nmol SP elicited the typical scratching, biting and licking (SBL) nociceptive response. This effect of SP was dose dependently (0.1-10 mg/kg) antagonized by Pronetupitant given intravenously 2 h before the peptide. Superimposable results were obtained using Netupitant. Pharmacokinetic studies performed in rats demonstrate that Pronetupitant, after i.v. administration, is quickly (few minutes) and completely converted to Netupitant. Collectively the present results indicated that Pronetupitant acts in vitro as selective NK1 antagonist more potent than Netupitant. However based on the short half-life measured for Pronetupitant in rats, the in vivo action of Pronetupitant can be entirely interpreted as due to its conversion to Netupitant. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Natriuretic peptides in cardiometabolic regulation and disease

    DEFF Research Database (Denmark)

    Zois, Nora E; Bartels, Emil D; Hunter, Ingrid

    2014-01-01

    these conditions can coexist and potentially lead to heart failure, a syndrome associated with a functional natriuretic peptide deficiency despite high circulating concentrations of immunoreactive peptides. Therefore, dysregulation of the natriuretic peptide system, a 'natriuretic handicap', might be an important...

  9. Radiolabeling of methionine containing proteins and peptides

    International Nuclear Information System (INIS)

    Garlick, R.K.; Jirousek, L.

    1986-01-01

    A process for radiolabeling methionine-containing peptides and proteins is disclosed. The process comprises the steps of oxidizing the protein or peptide, radiolabeling and reducing the radiolabeled protein or peptide. (author)

  10. PEG spacers of different length influence the biological profile of bombesin-based radiolabeled antagonists

    International Nuclear Information System (INIS)

    Jamous, Mazen; Tamma, Maria L.; Gourni, Eleni; Waser, Beatrice; Reubi, Jean C.; Maecke, Helmut R.; Mansi, Rosalba

    2014-01-01

    Introduction: The gastrin-releasing peptide receptor (GRPR) was shown to be expressed with high density on several types of cancers. Radiolabeled peptides for imaging and targeted radionuclide therapy have been developed. In this study, we evaluated the potential of statine-based bombesin antagonists, conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) through oligoethyleneglycol spacers, labeled with 177 Lu and we determined the effect of polyethyleneglycol (PEG) spacer length on in vitro and in vivo properties. Methods: The bombesin antagonists were synthesized on solid phase using Fmoc chemistry; the spacers Fmoc-dPEG x -OH (x = 2, 4, 6 and 12) and the DOTA(tBu) 3 were coupled using a standard procedure. The peptides were labeled with 177 Lu and evaluated in vitro (lipophilicity, serum stability, internalization and binding affinity assays). Biodistribution studies were performed in PC-3 tumor-bearing nude mice. Results: The solid-phase synthesis was straightforward with an overall yield ranging from 30% to 35% based on the first Fmoc cleavage. The hydrophilicity increased with spacer length (logD: − 1.95 vs − 2.22 of PEG 2 and PEG 12 analogs, respectively). There is a tendency of increased serum stability by increasing the spacer length (T 1/2 = 246 ± 4 and 584 ± 20 for PEG 2 and PEG 6 analogs, respectively) which seems to reverse with the PEG 12 analog. The IC 50 values are similar with the only significant difference of the PEG 12 analog. The 177 Lu-labeled PEG 4 and PEG 6 conjugates showed similar pharmacokinetic with high tumor uptake and excellent tumor-to-kidney ratios (7.8 and 9.7 at 4 h for the PEG 4 and PEG 6 derivatives, respectively). The pancreas uptake was relatively high at 1 h but it shows fast washout (0.46% ± 0.02% IA/g and 0.29% ± 0.08% IA/g already at 4 h). Conclusion: Among all the studied analogs the PEG 4 and PEG 6 showed significantly better properties. The very high tumor-to-non-target organ ratios, in

  11. Antagonistic neural networks underlying differentiated leadership roles

    Science.gov (United States)

    Boyatzis, Richard E.; Rochford, Kylie; Jack, Anthony I.

    2014-01-01

    The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950s. Recent research in neuroscience suggests that the division between task-oriented and socio-emotional-oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks – the task-positive network (TPN) and the default mode network (DMN). Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task-oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions, and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success. PMID:24624074

  12. Antagonistic Neural Networks Underlying Differentiated Leadership Roles

    Directory of Open Access Journals (Sweden)

    Richard Eleftherios Boyatzis

    2014-03-01

    Full Text Available The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950’s. Recent research in neuroscience suggests that the division between task oriented and socio-emotional oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks -- the Task Positive Network (TPN and the Default Mode Network (DMN. Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success.

  13. Antagonistic neural networks underlying differentiated leadership roles.

    Science.gov (United States)

    Boyatzis, Richard E; Rochford, Kylie; Jack, Anthony I

    2014-01-01

    The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950s. Recent research in neuroscience suggests that the division between task-oriented and socio-emotional-oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks - the task-positive network (TPN) and the default mode network (DMN). Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task-oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions, and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success.

  14. Cannabinoid receptor antagonists: pharmacological opportunities, clinical experience, and translational prognosis.

    Science.gov (United States)

    Janero, David R; Makriyannis, Alexandros

    2009-03-01

    The endogenous cannabinoid (CB) (endocannabinoid) signaling system is involved in a variety of (patho)physiological processes, primarily by virtue of natural, arachidonic acid-derived lipids (endocannabinoids) that activate G protein-coupled CB1 and CB2 receptors. A hyperactive endocannabinoid system appears to contribute to the etiology of several disease states that constitute significant global threats to human health. Consequently, mounting interest surrounds the design and profiling of receptor-targeted CB antagonists as pharmacotherapeutics that attenuate endocannabinoid transmission for salutary gain. Experimental and clinical evidence supports the therapeutic potential of CB1 receptor antagonists to treat overweight/obesity, obesity-related cardiometabolic disorders, and substance abuse. Laboratory data suggest that CB2 receptor antagonists might be effective immunomodulatory and, perhaps, anti-inflammatory drugs. One CB1 receptor antagonist/inverse agonist, rimonabant, has emerged as the first-in-class drug approved outside the United States for weight control. Select follow-on agents (taranabant, otenabant, surinabant, rosonabant, SLV-319, AVE1625, V24343) have also been studied in the clinic. However, rimonabant's market withdrawal in the European Union and suspension of rimonabant's, taranabant's, and otenabant's ongoing development programs have highlighted some adverse clinical side effects (especially nausea and psychiatric disturbances) of CB1 receptor antagonists/inverse agonists. Novel CB1 receptor ligands that are peripherally directed and/or exhibit neutral antagonism (the latter not affecting constitutive CB1 receptor signaling) may optimize the benefits of CB1 receptor antagonists while minimizing any risk. Indeed, CB1 receptor-neutral antagonists appear from preclinical data to offer efficacy comparable to or better than that of prototype CB1 receptor antagonists/inverse agonists, with less propensity to induce nausea. Continued

  15. Peptide radiopharmaceuticals in nuclear medicine

    International Nuclear Information System (INIS)

    Blok, D.; Vermeij, P.; Feitsma, R.I.J.; Pauwels, E.J.K.

    1999-01-01

    This article reviews the labelling of peptides that are recognised to be of interest for nuclear medicine or are the subject of ongoing nuclear medicine research. Applications and approaches to the labelling of peptide radiopharmaceuticals are discussed, and drawbacks in their development considered. (orig.)

  16. Antimicrobial peptides in the airway.

    Science.gov (United States)

    Laube, D M; Yim, S; Ryan, L K; Kisich, K O; Diamond, G

    2006-01-01

    The airway provides numerous defense mechanisms to prevent microbial colonization by the large numbers of bacteria and viruses present in ambient air. An important component of this defense is the antimicrobial peptides and proteins present in the airway surface fluid (ASF), the mucin-rich fluid covering the respiratory epithelium. These include larger proteins such as lysozyme and lactoferrin, as well as the cationic defensin and cathelicidin peptides. While some of these peptides, such as human beta-defensin (hBD)-1, are present constitutively, others, including hBD2 and -3 are inducible in response to bacterial recognition by Toll-like receptor-mediated pathways. These peptides can act as microbicides in the ASF, but also exhibit other activities, including potent chemotactic activity for cells of the innate and adaptive immune systems, suggesting they play a complex role in the host defense of the airway. Inhibition of antimicrobial peptide activity or gene expression can result in increased susceptibility to infections. This has been observed with cystic fibrosis (CF), where the CF phenotype leads to reduced antimicrobial capacity of peptides in the airway. Pathogenic virulence factors can inhibit defensin gene expression, as can environmental factors such as air pollution. Such an interference can result in infections by airway-specific pathogens including Bordetella bronchiseptica, Mycobacterium tuberculosis, and influenza virus. Research into the modulation of peptide gene expression in animal models, as well as the optimization of peptide-based therapeutics shows promise for the treatment and prevention of airway infectious diseases.

  17. 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...

  18. Chemical Synthesis of Antimicrobial Peptides.

    Science.gov (United States)

    Münzker, Lena; Oddo, Alberto; Hansen, Paul R

    2017-01-01

    Solid-phase peptide synthesis (SPPS) is the method of choice for chemical synthesis of peptides. In this nonspecialist review, we describe commonly used resins, linkers, protecting groups, and coupling reagents in 9-fluorenylmethyloxycarbonyl (Fmoc) SPPS. Finally, a detailed protocol for manual Fmoc SPPS is presented.

  19. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    N.D. Zegers (Netty)

    1995-01-01

    textabstractSynthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps

  20. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the

  1. Urinary Peptides in Rett Syndrome.

    Science.gov (United States)

    Solaas, K. M.; Skjeldal, O.; Gardner, M. L. G.; Kase, B. F.; Reichelt, K. L.

    2002-01-01

    A study found a significantly higher level of peptides in the urine of 53 girls with Rett syndrome compared with controls. The elevation was similar to that in 35 girls with infantile autism. Levels of peptides were lower in girls with classic Rett syndrome than those with congenital Rett syndrome. (Contains references.) (Author/CR)

  2. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  3. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Mohammad eKhanfar

    2016-05-01

    Full Text Available With the very recent market approval of pitolisant (Wakix®, the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures.

  4. 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.

  5. In vitro and in vivo effects of kisspeptin antagonists p234, p271, p354, and p356 on GPR54 activation.

    Directory of Open Access Journals (Sweden)

    C H J Albers-Wolthers

    Full Text Available Kisspeptins (KPs and their receptor (GPR54 or KiSS1R play a key-role in regulation of the hypothalamic-pituitary-gonadal axis and are therefore interesting targets for therapeutic interventions in the field of reproductive endocrinology. As dogs show a rapid and robust LH response after the administration of KP10, they can serve as a good animal model for research concerning KP signaling. The aims of the present study were to test the antagonistic properties of KP analogs p234, p271, p354, and p356 in vitro, by determining the intracellular Ca2+ response of CHEM1 cells that stably express human GPR54, and to study the in vivo effects of these peptides on basal plasma LH concentration and the KP10-induced LH response in female dogs. Exposure of the CHEM1 cells to KP-10 resulted in a clear Ca2+ response. P234, p271, p354, and p356 did not prevent or lower the KP10-induced Ca2+ response. Moreover, the in vivo studies in the dogs showed that none of these supposed antagonists lowered the basal plasma LH concentration and none of the peptides lowered the KP10-induced LH response. In conclusion, p234, p271, p354, and p356 had no antagonistic effects in vitro nor any effect on basal and kisspeptin-stimulated plasma LH concentration in female dogs.

  6. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  7. Purification and use of E. coli peptide deformylase for peptide deprotection in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia; Sonke, Theo; Quaedflieg, Peter J.; Janssen, Dick B.

    Peptide deformylases (PDFs) catalyze the removal of the formyl group from the N-terminal methionine residue in nascent polypeptide chains in prokaryotes. Its deformylation activity makes PDF an attractive candidate for the biocatalytic deprotection of formylated peptides that are used in

  8. Practical recommendations for calcium channel antagonist poisoning.

    Science.gov (United States)

    Rietjens, S J; de Lange, D W; Donker, D W; Meulenbelt, J

    2016-02-01

    Calcium channel antagonists (CCAs) are widely used for different cardiovascular disorders. At therapeutic doses, CCAs have a favourable side effect profile. However, in overdose, CCAs can cause serious complications, such as severe hypotension and bradycardia. Patients in whom a moderate to severe intoxication is anticipated should be observed in a monitored setting for at least 12 hours if an immediate-release formulation is ingested, and at least 24 hours when a sustained-release formulation (or amlodipine) is involved, even if the patient is asymptomatic. Initial treatment is aimed at gastrointestinal decontamination and general supportive care, i.e., fluid resuscitation and correction of metabolic acidosis and electrolyte disturbances. In moderate to severe CCA poisoning, a combined medical strategy might be indispensable, such as administration of vasopressors, intravenous calcium and hyperinsulinaemia/euglycaemia therapy. Especially hyperinsulinaemia/euglycaemia therapy is an important first-line treatment in CCA-overdosed patients in whom a large ingestion is suspected. High-dose insulin, in combination with glucose, seems to be most effective when used early in the intoxication phase, even when the patient shows hardly any haemodynamic instability. Intravenous lipid emulsion therapy should only be considered in patients with life-threatening cardiovascular toxicity, such as refractory shock, which is unresponsive to conventional therapies. When supportive and specific pharmacological measures fail to adequately reverse refractory conditions in CCA overdose, the use of extracorporeal life support should be considered. The efficacy of these pharmacological and non-pharmacological interventions generally advocated in CCA poisoning needs further in-depth mechanistic foundation, in order to improve individualised treatment of CCA-overdosed patients.

  9. Characterization and design of antagonistic shape memory alloy actuators

    International Nuclear Information System (INIS)

    Georges, T; Brailovski, V; Terriault, P

    2012-01-01

    Antagonistic shape memory actuators use opposing shape memory alloy (SMA) elements to create devices capable of producing differential motion paths and two-way mechanical work in a very efficient manner. There is no requirement for additional bias elements to ‘re-arm’ the actuators and allow repetitive actuation. The work generation potential of antagonistic shape memory actuators is determined by specific SMA element characteristics and their assembly conditions. In this study, the selected SMA wires are assembled in antagonistic configuration and characterized using a dedicated test bench to evaluate their stress–strain characteristics as a function of the number of cycles. Using these functional characteristics, a so-called ‘working envelope’ is built to assist in the design of such an actuator. Finally, the test bench is used to simulate a real application of an antagonistic actuator (case study). (paper)

  10. A SELECTIVE ANTAGONIST OF MINERALOCORTICOID RECEPTOR EPLERENONE IN CARDIOLOGY PRACTICE

    Directory of Open Access Journals (Sweden)

    B. B. Gegenava

    2015-01-01

    Full Text Available The role of aldosterone in pathophysiological processes is considered. The effects of the selective antagonist of mineralocorticoid receptor eplerenone are analyzed. The advantages of eplerenone compared with spironolactone are discussed.

  11. Complications of TNF-α antagonists and iron homeostasis

    Science.gov (United States)

    TNF-α is a central regulator of inflammation and its blockade downregulates other proinflammatory cytokines, chemokines, and growth factors. Subsequently, TNF-α antagonists are currently used in treatment regimens directed toward several inflammatory diseases. Despite a beneficia...

  12. Oral antiplatelet efficacy and specificity of a novel nonpeptide platelet GPIIb/IIIa receptor antagonist, DMP 802.

    Science.gov (United States)

    Mousa, S A; Olson, R E; Bozarth, J M; Lorelli, W; Forsythe, M S; Racanelli, A; Gibbs, S; Schlingman, K; Bozarth, T; Kapil, R; Wityak, J; Sielecki, T M; Wexler, R R; Thoolen, M J; Slee, A; Reilly, T M; Anderson, P S; Friedman, P A

    1998-08-01

    This study was undertaken to define the platelet glycoprotein alphaIIb beta3 integrin (GPII/IIIa) affinity, specificity, and oral antiplatelet efficacy of DMP 802, a small-molecule nonpeptide antiplatelet agent. Platelet GPIIb/IIIa integrin binding affinity and specificity for DMP 802 were determined by using binding and adhesion assays with cells from various species, including human. DMP 802 demonstrated a potent antiplatelet efficacy [median inhibitory concentration (IC50), 0.029 +/- 0.0042 microM] in inhibiting human platelet aggregation induced by 10 microM adenosine diphosphate (ADP), as assessed by light-transmittance aggregometry. DMP 802 inhibited 125I-fibrinogen binding to activated (ADP, epinephrine, and arachidonic acid at 100 microM each) gel purified human platelets with an IC50 of 0.012 +/- 0.003 microM. DMP 802 demonstrated tight association with unactivated human, baboon, or canine platelets (t(1/2) of dissociation, 32 +/- 2, 32 +/- 13, and 11 +/- 1 min, respectively). DMP 802 binds with high affinity to both unactivated and activated human platelets (Kd = 0.61 +/- 0.17, 0.57 +/- 0.21 nM, respectively). DMP 802 demonstrated species specificity in inhibiting platelet aggregation with IC50 values ranging from 0.025 to 0.092 microM (human, guinea pig, dog, swine, hamster) and 0.88-1.0 microM (rabbit and rat) in platelets obtained from these various species. DMP 802 demonstrated a high degree of specificity for platelet GPIIb/IIIa (alphaIIb/beta3) as compared with other integrins including alpha(v)beta3 (IC50, >10 microM), alpha(v)beta5 (IC50, >100 microM), alpha4beta1 (IC50, >100 microM), and alpha5beta1 (IC50, >10 microM). Oral antiplatelet efficacy of DMP 802 was examined after single oral (0.05-0.20 mg/kg) and after repeated oral dosing at 0.05 mg/kg daily for 5 days in mongrel dogs. Dose-dependent antiplatelet efficacy with an extended duration of antiplatelet efficacy was demonstrated based on ex vivo inhibition of platelet aggregation induced by

  13. Enhanced Chronic Pain Management Utilizing Chemokine Receptor Antagonists

    Science.gov (United States)

    2016-08-01

    AWARD NUMBER: W81XWH-15 1-0252 TITLE: Enhanced Chronic Pain Management Utilizing Chemokine Receptor Antagonists PRINCIPAL INVESTIGATOR...14 Jul 2016 4. TITLE AND SUBTITLE Enhanced Chronic Pain Management Utilizing Chemokine Receptor Antagonists 5a. CONTRACT NUMBER 5b. GRANT...Center for Substance Abuse Research Lewis Katz School of Medicine at Temple University 3500 N, Broad Street Philadelphia, PA 19140 AND ADDRESS(ES) 8

  14. Interleukin-2 receptor antagonists as induction therapy after heart transplantation

    DEFF Research Database (Denmark)

    Møller, Christian H; Gustafsson, Finn; Gluud, Christian

    2008-01-01

    About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras.......About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras....

  15. Value of the radiolabelled GLP-1 receptor antagonist exendin(9-39) for targeting of GLP-1 receptor-expressing pancreatic tissues in mice and humans

    International Nuclear Information System (INIS)

    Waser, Beatrice; Reubi, Jean Claude

    2011-01-01

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. Moreover, it was recently reported that antagonist tracers were superior to agonist tracers for somatostatin and gastrin-releasing peptide receptor targeting of tumours. The present preclinical study determines therefore the value of an established GLP-1 receptor antagonist for the in vitro visualization of GLP-1 receptor-expressing tissues in mice and humans. Receptor autoradiography studies with 125 I-GLP-1(7-36)amide agonist or 125 I-Bolton-Hunter-exendin(9-39) antagonist radioligands were performed in mice pancreas and insulinomas as well as in human insulinomas; competition experiments were performed in the presence of increasing concentration of GLP-1(7-36)amide or exendin(9-39). The antagonist 125 I-Bolton-Hunter-exendin(9-39) labels mouse pancreatic β-cells and mouse insulinomas, but it does not label human pancreatic β-cells and insulinomas. High affinity displacement (IC 50 approximately 2 nM) is observed in mouse β-cells and insulinomas with either the exendin(9-39) antagonist or GLP-1(7-36)amide agonist. For comparison, the agonist 125 I-GLP-1(7-36)amide intensively labels mouse pancreatic β-cells, mouse insulinoma and human insulinomas; high affinity displacement is observed for the GLP-1(7-36)amide in all tissues; however, a 5 and 20 times lower affinity is found for exendin(9-39) in the mouse and human tissues, respectively. This study reports a species-dependent behaviour of the GLP-1 receptor antagonist exendin(9-39) that can optimally target GLP-1 receptors in mice but not in human tissue. Due to its overly low binding affinity, this antagonist is an inadequate targeting agent for human GLP-1 receptor-expressing tissues, as opposed to the GLP-1 receptor agonist, GLP-1(7-36)amide. (orig.)

  16. Value of the radiolabelled GLP-1 receptor antagonist exendin(9-39) for targeting of GLP-1 receptor-expressing pancreatic tissues in mice and humans

    Energy Technology Data Exchange (ETDEWEB)

    Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, P.O. Box 62, Bern (Switzerland)

    2011-06-15

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. Moreover, it was recently reported that antagonist tracers were superior to agonist tracers for somatostatin and gastrin-releasing peptide receptor targeting of tumours. The present preclinical study determines therefore the value of an established GLP-1 receptor antagonist for the in vitro visualization of GLP-1 receptor-expressing tissues in mice and humans. Receptor autoradiography studies with {sup 125}I-GLP-1(7-36)amide agonist or {sup 125}I-Bolton-Hunter-exendin(9-39) antagonist radioligands were performed in mice pancreas and insulinomas as well as in human insulinomas; competition experiments were performed in the presence of increasing concentration of GLP-1(7-36)amide or exendin(9-39). The antagonist {sup 125}I-Bolton-Hunter-exendin(9-39) labels mouse pancreatic {beta}-cells and mouse insulinomas, but it does not label human pancreatic {beta}-cells and insulinomas. High affinity displacement (IC{sub 50} approximately 2 nM) is observed in mouse {beta}-cells and insulinomas with either the exendin(9-39) antagonist or GLP-1(7-36)amide agonist. For comparison, the agonist {sup 125}I-GLP-1(7-36)amide intensively labels mouse pancreatic {beta}-cells, mouse insulinoma and human insulinomas; high affinity displacement is observed for the GLP-1(7-36)amide in all tissues; however, a 5 and 20 times lower affinity is found for exendin(9-39) in the mouse and human tissues, respectively. This study reports a species-dependent behaviour of the GLP-1 receptor antagonist exendin(9-39) that can optimally target GLP-1 receptors in mice but not in human tissue. Due to its overly low binding affinity, this antagonist is an inadequate targeting agent for human GLP-1 receptor-expressing tissues, as opposed to the GLP-1 receptor agonist, GLP-1(7-36)amide. (orig.)

  17. Platelet-activating factor (PAF)-antagonists of natural origin.

    Science.gov (United States)

    Singh, Preeti; Singh, Ishwari Narayan; Mondal, Sambhu Charan; Singh, Lubhan; Garg, Vipin Kumar

    2013-01-01

    Presently herbal medicines are being used by about 80% of the world population for primary health care as they stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. The discovery of platelet activating factor antagonists (PAF antagonists) during these decades are going on with different framework, but the researchers led their efficiency in studying in vitro test models. Since it is assumed that PAF play a central role in etiology of many diseases in humans such as asthma, neuronal damage, migraine, cardiac diseases, inflammatory, headache etc. Present days instinctively occurring PAF antagonist exists as a specific grade of therapeutic agents for the humans against these and different diseases either laid hold of immunological or non-immunological types. Ginkgolide, cedrol and many other natural PAF antagonists such as andrographolide, α-bulnesene, cinchonine, piperine, kadsurenone, different Piper species' natural products and marine origin plants extracts or even crude drugs having PAF antagonist properties are being used currently against different inflammatory pathologies. This review is an attempt to summarize the data on PAF and action of natural PAF antagonists on it, which were evaluated by in vivo and in vitro assays. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Identification and functional analysis of a novel bradykinin inhibitory peptide in the venoms of New World Crotalinae pit vipers

    International Nuclear Information System (INIS)

    James Graham, Robert Leslie; Graham, Ciaren; McClean, Stephen; Chen, Tianbao; O'Rourke, Martin; Hirst, David; Theakston, David; Shaw, Chris

    2005-01-01

    A novel undecapeptide has been isolated and structurally characterized from the venoms of three species of New World pit vipers from the subfamily, Crotalinae. These include the Mexican moccasin (Agkistrodon bilineatus), the prairie rattlesnake (Crotalus viridis viridis), and the South American bushmaster (Lachesis muta). The peptide was purified from all three venoms using a combination of gel permeation chromatography and reverse-phase HPLC. Automated Edman degradation sequencing and MALDI-TOF mass spectrometry established its peptide primary structure as: Thr-Pro-Pro-Ala-Gly-Pro-Asp-Val-Gly-Pro-Arg-OH, with a non-protonated molecular mass of 1063.18 Da. A synthetic replicate of the peptide was found to be an antagonist of bradykinin action at the rat vascular B2 receptor. This is the first bradykinin inhibitory peptide isolated from snake venom. Database searching revealed the peptide to be highly structurally related (10/11 residues) with a domain residing between the bradykinin-potentiating peptide and C-type natriuretic peptide domains of a recently cloned precursor from tropical rattlesnake (Crotalus durissus terrificus) venom gland. BIP thus represents a novel biological entity from snake venom

  19. Delivery systems for antimicrobial peptides

    DEFF Research Database (Denmark)

    Nordström, Randi; Malmsten, Martin

    2017-01-01

    on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems......, or through achieving co-localization with intracellular pathogens. Here, an overview is provided of the current understanding of delivery systems for antimicrobial peptides, with special focus on AMP-carrier interactions, as well as consequences of these interactions for antimicrobial and related biological...

  20. alpha2-Adrenoceptor antagonists reverse the 5-HT2 receptor antagonist suppression of head-twitch behavior in mice.

    Science.gov (United States)

    Matsumoto, K; Mizowaki, M; Thongpraditchote, S; Murakami, Y; Watanabe, H

    1997-03-01

    The alpha2-adrenoceptor agonist clonidine, as well as 5-HT2 receptor antagonists, reportedly suppress 5-HT2 receptor-mediated head-twitch behavior. We investigated the effect of alpha2-adrenoceptor antagonists on the suppressive action of 5-HT2 receptor antagonists in mice pretreated with the noradrenaline toxin 6-hydroxydopamine (6-OHDA) or the 5-HT synthesis inhibitor p-chlorophenylalanine (p-CPA). In normal mice, idazoxan (0.08-0.2 mg/kg, IP) or yohimbine (0.2-2.0 mg/kg, IP), both alpha2-adrenoceptor antagonists, had no effect on the head-twitch response caused by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT; 16 mg/kg, IP), but idazoxan significantly enhanced the response at 0.5 mg/kg. On the other hand, these alpha2-adrenoceptor antagonists, at doses that had no effect on the basal number of head-twitches (idazoxan 0.2 mg/kg and yohimbine 0.5 mg/kg), significantly attenuated not only the suppressive effect of clonidine (0.01 mg/kg, IP) on head-twitch response but also that of the 5-HT2 receptor antagonist ritanserin (0.03 mg/kg, IP). Moreover, idazoxan (0.2 mg/kg) also significantly reversed the inhibition by 0.01 mg/kg (IP) ketanserin, a selective 5-HT2 receptor antagonist. Pretreatment with 6-OHDA plus nomifensine but not with p-CPA significantly attenuated the effect of idazoxan (0.2-0.5 mg/kg) on the ritanserin inhibition of the head-twitch response. Prazosin, an alpha1-adrenoceptor antagonist, dose-dependently suppressed the response, and the effect of prazosin (1.25 mg/kg) was significantly attenuated by 0.5 mg/kg idazoxan. These results indicate that endogenous noradrenaline is involved in the apparent antagonistic interaction between selective alpha2-adrenoceptor antagonists and 5-HT2 receptor antagonists in the head-twitch response, and suggest that noradrenaline stimulation of alpha1-adrenoceptors may be involved in this apparent antagonism.

  1. Novel peptides with tyrosinase inhibitory activity

    NARCIS (Netherlands)

    Schurink, M.; Berkel, van W.J.H.; Wichers, H.J.; Boeriu, C.G.

    2007-01-01

    Tyrosinase inhibition by peptides may find its application in food, cosmetics or medicine. In order to identify novel tyrosinase inhibitory peptides, protein-based peptide libraries made by SPOT synthesis were used to screen for peptides that show direct interaction with tyrosinase. One of the

  2. Characterization of Synthetic Peptides by Mass Spectrometry.

    Science.gov (United States)

    Prabhala, Bala K; Mirza, Osman; Højrup, Peter; Hansen, Paul R

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI-TOF-MS and LC-MS of synthetic peptides.

  3. Structure of the nociceptin/orphanin FQ receptor in complex with a peptide mimetic

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Aaron A.; Liu, Wei; Chun, Eugene; Katritch, Vsevolod; Wu, Huixian; Vardy, Eyal; Huang, Xi-Ping; Trapella, Claudio; Guerrini, Remo; Calo, Girolamo; Roth, Bryan L.; Cherezov, Vadim; Stevens, Raymond C. (Ferrara); (Scripps); (UNC)

    2012-07-11

    Members of the opioid receptor family of G-protein-coupled receptors (GPCRs) are found throughout the peripheral and central nervous system, where they have key roles in nociception and analgesia. Unlike the 'classical' opioid receptors, {delta}, {kappa} and {mu} ({delta}-OR, {kappa}-OR and {mu}-OR), which were delineated by pharmacological criteria in the 1970s and 1980s, the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP, also known as ORL-1) was discovered relatively recently by molecular cloning and characterization of an orphan GPCR. Although it shares high sequence similarity with classical opioid GPCR subtypes ({approx}60%), NOP has a markedly distinct pharmacology, featuring activation by the endogenous peptide N/OFQ, and unique selectivity for exogenous ligands. Here we report the crystal structure of human NOP, solved in complex with the peptide mimetic antagonist compound-24 (C-24) (ref. 4), revealing atomic details of ligand-receptor recognition and selectivity. Compound-24 mimics the first four amino-terminal residues of the NOP-selective peptide antagonist UFP-101, a close derivative of N/OFQ, and provides important clues to the binding of these peptides. The X-ray structure also shows substantial conformational differences in the pocket regions between NOP and the classical opioid receptors {kappa} (ref. 5) and {mu} (ref. 6), and these are probably due to a small number of residues that vary between these receptors. The NOP-compound-24 structure explains the divergent selectivity profile of NOP and provides a new structural template for the design of NOP ligands.

  4. Vitamin K antagonist use and mortality in dialysis patients.

    Science.gov (United States)

    Voskamp, Pauline W M; Rookmaaker, Maarten B; Verhaar, Marianne C; Dekker, Friedo W; Ocak, Gurbey

    2018-01-01

    The risk-benefit ratio of vitamin K antagonists for different CHA2DS2-VASc scores in patients with end-stage renal disease treated with dialysis is unknown. The aim of this study was to investigate the association between vitamin K antagonist use and mortality for different CHA2DS2-VASc scores in a cohort of end-stage renal disease patients receiving dialysis treatment. We prospectively followed 1718 incident dialysis patients. Hazard ratios were calculated for all-cause and cause-specific (stroke, bleeding, cardiovascular and other) mortality associated with vitamin K antagonist use. Vitamin K antagonist use as compared with no vitamin K antagonist use was associated with a 1.2-fold [95% confidence interval (95% CI) 1.0-1.5] increased all-cause mortality risk, a 1.5-fold (95% CI 0.6-4.0) increased stroke mortality risk, a 1.3-fold (95% CI 0.4-4.2) increased bleeding mortality risk, a 1.2-fold (95% CI 0.9-1.8) increased cardiovascular mortality risk and a 1.2-fold (95% CI 0.8-1.6) increased other mortality risk after adjustment. Within patients with a CHA2DS2-VASc score ≤1, vitamin K antagonist use was associated with a 2.8-fold (95% CI 1.0-7.8) increased all-cause mortality risk as compared with no vitamin K antagonist use, while vitamin K antagonist use within patients with a CHA2DS2-VASc score ≥2 was not associated with an increased mortality risk after adjustment. Vitamin K antagonist use was not associated with a protective effect on mortality in the different CHA2DS2-VASc scores in dialysis patients. The lack of knowledge on the indication for vitamin K antagonist use could lead to confounding by indication. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  5. Dissociative effects of CNS peptides with some unusual applications of RIA

    International Nuclear Information System (INIS)

    Kastin, A.J.; Banks, W.A.; Olson, D.

    1981-01-01

    The central effects of many peripherally administered peptides provide strong evidence for the dissociative aspects of their multiple, independent actions. The actions of MSH and MIF-1 on the brain are not mediated by the pituitary gland or the skin. The actions of the opiate peptides on behaviour do not require analgesia. In addition to supporting these observations by demonstrating the presence of peptides in brain tissue, radioimmunological techniques have provided two unusual approaches for the field. In one of them, an antibody generated against the tripeptide MIF-1 was found to have a greater affinity for the tetrapeptide Tyr-MIF-1 than MIF-1. This permitted description of the presence of a novel peptide in the pineal gland. MIF-1 may also represent a class of naturally occurring opiate antagonists since its administration results in naloxone-like activity in many, but not all, test situations. In the second unusual application of RIA, an antibody against the nonapeptide DSIP was generated that required almost the entire molecule for immunoreactivity. This was used to demonstrate the passage of intact DSIP into the CSF of dogs and, in very small amounts, brain tissue of rats after peripheral administration. It is expected that radioimmunological techniques will continue to be useful in explaining the dissociative aspects of brain peptides. (Auth.)

  6. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents

    Directory of Open Access Journals (Sweden)

    Julio Valdivia-Silva

    2015-06-01

    Full Text Available Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/ chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer.

  7. Neoglycolipidation for modulating peptide properties

    DEFF Research Database (Denmark)

    van Witteloostuijn, Søren Blok

    regulation of appetite, food intake, and glucose homeostasis, and many of these peptides display a signicant potential for treatment of obesity and/or type 2 diabetes. This Ph.D. thesis describes three novel approaches for utilizing gut peptides as the starting point for developing obesity and diabetes drugs....... Subsequent stereological analyses of the pancreata showed that chronic treatment with GUB06-046 led to increased cell mass in db/db mice. The results of projects I and II clearly illustrate how chemical modications can improve the pharmacological properties of native peptides. Collectively, the ndings...... of this thesis contribute to emphasize the tremendous therapeutic potential of gut peptides for treatment of obesity and diabetes....

  8. New vasoactive peptides in cirrhosis

    DEFF Research Database (Denmark)

    Kimer, Nina; Goetze, Jens Peter; Bendtsen, Flemming

    2014-01-01

    BACKGROUND: Patients with cirrhosis have substantial circulatory imbalance between vasoconstrictive and vasodilating forces. The study of circulatory vasoactive peptides may provide important pathophysiological information. This study aimed to assess concentrations, organ extraction and relations...

  9. Moonlighting peptides with emerging function.

    Directory of Open Access Journals (Sweden)

    Jonathan G Rodríguez Plaza

    Full Text Available Hunter-killer peptides combine two activities in a single polypeptide that work in an independent fashion like many other multi-functional, multi-domain proteins. We hypothesize that emergent functions may result from the combination of two or more activities in a single protein domain and that could be a mechanism selected in nature to form moonlighting proteins. We designed moonlighting peptides using the two mechanisms proposed to be involved in the evolution of such molecules (i.e., to mutate non-functional residues and the use of natively unfolded peptides. We observed that our moonlighting peptides exhibited two activities that together rendered a new function that induces cell death in yeast. Thus, we propose that moonlighting in proteins promotes emergent properties providing a further level of complexity in living organisms so far unappreciated.

  10. Early Illustrations of Geste Antagoniste in Cervical and Generalized Dystonia

    Directory of Open Access Journals (Sweden)

    Emmanuel Broussolle

    2015-09-01

    Full Text Available Background: Geste antagoniste, or sensory trick, is a voluntary maneuver that temporarily reduces the severity of dystonic postures or movements. We present a historical review of early reports and illustrations of geste antagoniste.Results: In 1894, Brissaud described this phenomenon in Paris in patients with torticollis. He noted that a violent muscular contraction could be reversed by a minor voluntary action. He considered the improvement obtained by what he called “simple mannerisms, childish behaviour or fake pathological movements” was proof of the psychogenic origin of what he named mental torticollis. This concept was supported by photographical illustrations of the patients. The term geste antagoniste was used by Brissaud’s pupils, Meige and Feindel, in their 1902 monograph on movement disorders. Other reports and illustrations of this sign were published in Europe between 1894 and 1906. Although not mentioned explicitly, geste antagoniste was also illustrated in a case report of generalized dystonia in Oppenheim’s 1911 seminal description of dystonia musculorum deformans in Berlin.Discussion: Brissaud-Meige’s misinterpretation of the geste antagoniste unfortunately anchored the psychogenic origin of dystonia for decades. In New York, Herz brought dystonia back into the realm of organic neurology in 1944. Thereafter, it was given prominence by other authors, notably Fahn and Marsden in the 1970–1980s. Nowadays, neurologists routinely investigate for geste antagoniste when a dystonic syndrome is suspected, because it provides a further argument in favor of dystonia. The term alleviating maneuver was proposed in 2014 to replace sensory trick or geste antagoniste. This major sign is now part of the motor phenomenology of the 2013 Movement Disorder Society’s classification of dystonia.

  11. Matrix-assisted peptide synthesis on nanoparticles.

    Science.gov (United States)

    Khandadash, Raz; Machtey, Victoria; Weiss, Aryeh; Byk, Gerardo

    2014-09-01

    We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides. The matrix-assisted synthesis on nanoparticles was proved by generating various biologically relevant peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  12. Material Binding Peptides for Nanotechnology

    Directory of Open Access Journals (Sweden)

    Urartu Ozgur Safak Seker

    2011-02-01

    Full Text Available Remarkable progress has been made to date in the discovery of material binding peptides and their utilization in nanotechnology, which has brought new challenges and opportunities. Nowadays phage display is a versatile tool, important for the selection of ligands for proteins and peptides. This combinatorial approach has also been adapted over the past decade to select material-specific peptides. Screening and selection of such phage displayed material binding peptides has attracted great interest, in particular because of their use in nanotechnology. Phage display selected peptides are either synthesized independently or expressed on phage coat protein. Selected phage particles are subsequently utilized in the synthesis of nanoparticles, in the assembly of nanostructures on inorganic surfaces, and oriented protein immobilization as fusion partners of proteins. In this paper, we present an overview on the research conducted on this area. In this review we not only focus on the selection process, but also on molecular binding characterization and utilization of peptides as molecular linkers, molecular assemblers and material synthesizers.

  13. Purification and sequencing of radish seed calmodulin antagonists phosphorylated by calcium-dependent protein kinase.

    Science.gov (United States)

    Polya, G M; Chandra, S; Condron, R

    1993-02-01

    A family of radish (Raphanus sativus) calmodulin antagonists (RCAs) was purified from seeds by extraction, centrifugation, batch-wise elution from carboxymethyl-cellulose, and high performance liquid chromatography (HPLC) on an SP5PW cation-exchange column. This RCA fraction was further resolved into three calmodulin antagonist polypeptides (RCA1, RCA2, and RCA3) by denaturation in the presence of guanidinium HCl and mercaptoethanol and subsequent reverse-phase HPLC on a C8 column eluted with an acetonitrile gradient in the presence of 0.1% trifluoroacetic acid. The RCA preparation, RCA1, RCA2, RCA3, and other radish seed proteins are phosphorylated by wheat embryo Ca(2+)-dependent protein kinase (CDPK). The RCA preparation contains other CDPK substrates in addition to RCA1, RCA2, and RCA3. The RCA preparation, RCA1, RCA2, and RCA3 inhibit chicken gizzard calmodulin-dependent myosin light chain kinase assayed with a myosin-light chain-based synthetic peptide substrate (fifty percent inhibitory concentrations of RCA2 and RCA3 are about 7 and 2 microM, respectively). N-terminal sequencing by sequential Edman degradation of RCA1, RCA2, and RCA3 revealed sequences having a high homology with the small subunit of the storage protein napin from Brassica napus and with related proteins. The deduced amino acid sequences of RCA1, RCA2, RCA3, and RCA3' (a subform of RCA3) have agreement with average molecular masses from electrospray mass spectrometry of 4537, 4543, 4532, and 4560 kD, respectively. The only sites for serine phosphorylation are near or at the C termini and hence adjacent to the sites of proteolytic precursor cleavage.

  14. Advances in Peptide Receptor Radionuclide Therapy.

    Science.gov (United States)

    Sabet, Amir; Biersack, Hans-Jürgen; Ezziddin, Samer

    2016-01-01

    Peptide receptor radionuclide therapy (PRRT) is a very effective treatment modality for advanced neuroendocrine tumors (NETs), representing a teaching model for truly targeted antitumor therapy. With the growing cumulative evidence of PRRT in various treatment settings, we are witnessing increased perception of this modality as a potent treatment option in advanced disease. Although most data derives from retrospective analyses, results from prospective comparative evaluations, such as the NETTER-1 trial, are eagerly awaited and should help to raise PRRT to a higher level of evidence. At the same time, as increased levels of evidence are anticipated by prospective evaluations, further methodological improvements are going on in different ways and aspects of radionuclide therapy, mainly regarding the radiopharmaceuticals, the combination with other radionuclides or cytotoxic drugs, and the route of administration. Although diversity of PRRT increases-not supporting cumulative evidence as opposed to uniform treatment-it is very likely to achieve significant increase of efficacy by these efforts in the near future. As the intraarterial administration of PRRT agents in liver-dominant metastatic disease has the potential to improve outcome, it would have to be shown as to which patients would benefit from this approach, to what extent the benefit would be, and to when it would justify the increased efforts for patients and treating institutes. The approach of combining cytotoxic or radiosensitizing drugs with the PRRT agents seems to trigger a major boost of efficacy in pancreatic NET. The midterm future would show the extent of benefit in terms of long-term outcome and would probably lead to inclusion into clinical routine for this particular NET entity. The translation of somatostatin-receptor antagonists into human application represents another major source of significant improvement in terms of PRRT's benefit-toxicity ratio. Eventually, it may not be completely

  15. A rapid and clean synthetic approach to cyclic peptides via micro-flow peptide chain elongation and photochemical cyclization: synthesis of a cyclic RGD peptide.

    Science.gov (United States)

    Mifune, Yuto; Nakamura, Hiroyuki; Fuse, Shinichiro

    2016-11-29

    A cyclic RGD peptide was efficiently synthesized based on micro-flow, triphosgene-mediated peptide chain elongation and micro-flow photochemical macrolactamization. Our approach enabled a rapid (amidation for peptide chain elongation peptide.

  16. [Octarphin--Nonopioid Peptide of the Opioid Origin].

    Science.gov (United States)

    Navolotskaya, E V

    2015-01-01

    The data on the properties and mechanism of action of the peptide octarphin (TPLVTLFK, the fragment 12-19 of β-endorphin)--a selective agonist of nonopioid (insensitive to the action of the opioid antagonist naloxone) β-endorphin receptor found on n immune cells (peritoneal macrophages, T and B lymphocytes of spleen and blood), endocrine (adrenal cortex, hypothalamus), cardiovascular (cardiomyocytes) systems are analyzed and systematized. Binding to the receptor octarphin increases increases the mitogen-induced pro- liferation of human and mouse T and B lymphocytes in vitro, activates murine peritoneal macrophages in vitro and in vivo, stimulates growth of human T-lymphoblast cell lines Jurkat and MT-4, inhibits adenylate cyclase activity of rat adrenal cortex membranes and suppresses the secretion of glucocorticoids from the adrenal gland into the blood. It was shown that in a concentration range of 1-1000 nM the peptide increases the activity of inducible NO-synthase (iNOS), and the content of NO and cGMP in lipopolysaccharide-activated murine peritoneal macrophages. Taking into account that NO acts as a primary activator of soluble guanylate cyclase (sGC), it can be assumed that the activating effect of octarphin on macrophages is realized in the following way: increase in th iNOS expression --> increase in the NO production --> increase in the sGC activity --> increase in intracellular levels of cGMP.

  17. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  18. Peptides and Food Intake

    Directory of Open Access Journals (Sweden)

    Carmen Sobrino Crespo

    2014-04-01

    Full Text Available Nutrients created by the digestion of food are proposed to active G protein coupled receptors on the luminal side of enteroendocrine cells e.g. the L-cell. This stimulates the release of gut hormones. Hormones released from the gut and adipose tissue play an important rol in the regulation of food intake and energy expenditure (1.Many circulating signals, including gut hormones, can influence the activity of the arcuate nucleus (ARC neurons directly, after passing across the median eminence. The ARC is adjacent to the median eminence, a circumventricular organ with fenestrated capillaries and hence an incomplete blood-brain barrier (2. The ARC of the hypothalamus is believed to play a crucial role in the regulation of food intake and energy homeostasis. The ARC contains two populations of neurons with opposing effect on food intake (3. Medially located orexigenic neurons (i.e those stimulating appetite express neuropeptide Y (NPY and agouti-related protein (AgRP (4-5. Anorexigenic neurons (i.e. those inhibiting appetite in the lateral ARC express alpha-melanocyte stimulating hormone (α-MSH derived from pro-opiomelanocortin (POMC and cocaine and amphetamine-regulated transcript (CART (6. The balance between activities of these neuronal circuits is critical to body weight regulation.In contrast, other peripheral signals influence the hypothalamus indirectly via afferent neuronal pathway and brainstem circuits. In this context gastrointestinal’s vagal afferents are activated by mechanoreceptors and chemoreceptors, and converge in the nucleus of the tractus solitaries (NTS of the brainstem. Neuronal projections from the NTS, in turn, carry signals to the hypotalamus (1, 7. Gut hormones also alter the activity of the ascending vagal pathway from the gut to the brainstem. In the cases of ghrelin and Peptide tyrosine tyrosine (PYY, there are evidences for both to have a direct action on the arcuate nucleus and an action via the vagus nerve a

  19. Exploration of the Medicinal Peptide Space.

    Science.gov (United States)

    Gevaert, Bert; Stalmans, Sofie; Wynendaele, Evelien; Taevernier, Lien; Bracke, Nathalie; D'Hondt, Matthias; De Spiegeleer, Bart

    2016-01-01

    The chemical properties of peptide medicines, known as the 'medicinal peptide space' is considered a multi-dimensional subset of the global peptide space, where each dimension represents a chemical descriptor. These descriptors can be linked to biofunctional, medicinal properties to varying degrees. Knowledge of this space can increase the efficiency of the peptide-drug discovery and development process, as well as advance our understanding and classification of peptide medicines. For 245 peptide drugs, already available on the market or in clinical development, multivariate dataexploration was performed using peptide relevant physicochemical descriptors, their specific peptidedrug target and their clinical use. Our retrospective analysis indicates that clusters in the medicinal peptide space are located in a relatively narrow range of the physicochemical space: dense and empty regions were found, which can be explored for the discovery of novel peptide drugs.

  20. 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.

  1. Perspectives and Peptides of the Next Generation

    Science.gov (United States)

    Brogden, Kim A.

    Shortly after their discovery, antimicrobial peptides from prokaryotes and eukaryotes were recognized as the next potential generation of pharmaceuticals to treat antibiotic-resistant bacterial infections and septic shock, to preserve food, or to sanitize surfaces. Initial research focused on identifying the spectrum of antimicrobial agents, determining the range of antimicrobial activities against bacterial, fungal, and viral pathogens, and assessing the antimicrobial activity of synthetic peptides versus their natural counterparts. Subsequent research then focused on the mechanisms of antimicrobial peptide activity in model membrane systems not only to identify the mechanisms of antimicrobial peptide activity in microorganisms but also to discern differences in cytotoxicity for prokaryotic and eukaryotic cells. Recent, contemporary work now focuses on current and future efforts to construct hybrid peptides, peptide congeners, stabilized peptides, peptide conjugates, and immobilized peptides for unique and specific applications to control the growth of microorganisms in vitro and in vivo.

  2. Emerging role of orexin antagonists in insomnia therapeutics: An update on SORAs and DORAs.

    Science.gov (United States)

    Kumar, Anil; Chanana, Priyanka; Choudhary, Supriti

    2016-04-01

    The pharmacological management of insomnia has lately become a challenge for researchers worldwide. As per the third International Classification of Sleep disorders (ICSD-3) insomnia can be defined as a state with repeated difficulty in sleep initiation, duration, consolidation, or quality that occurs despite adequate opportunity and circumstances for sleep, and results in some form of daytime impairment. The conventional treatments approved for management of insomnia were benzodiazepines (BZDs) (estazolam, quazepam, triazolam, flurazepam and temazepam) and non-BZDs, also known as z-drugs (zaleplon, zolpidem, and eszopiclone), tricyclic antidepressant (TCA) doxepin as well as melatonin agonists, e.g. ramelteon. But the potential of these agents to address sleep problems has been limited due to substantial side effects associated with them like hangover, dependence and tolerance, rebound insomnia, muscular atonia, inhibition of respiratory system, cognitive dysfunctions, and increased anxiety. Recently, orexin neuropeptides have been identified as regulators of transition between wakefulness and sleep and documented to aid an initial transitory effect towards wakefulness by activating cholinergic/monoaminergic neural pathways of the ascending arousal system. This has led to the development of orexin peptides and receptors, as possible therapeutic targets for the treatment of sleep disorders with the advantage of having lesser side effects as compared to conventional treatments. The present review focuses on the orexin peptides and receptors signifying their physiological profile as well as the development of orexin receptor antagonists as novel strategies in sleep medicine. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  3. First Irish birth following IVF therapy using antagonist protocol.

    LENUS (Irish Health Repository)

    Mocanu, E V

    2012-02-01

    BACKGROUND: During in vitro fertilization (IVF), the prevention of a premature LH surge was traditionally achieved using a gonadotrophin releasing hormone agonist (GnRH-a), and more recently, a GnRH antagonist. AIMS: We report a case of a 37 year old treated using the GnRH antagonist in a second completed cycle of IVF. METHODS: IVF was performed for primary infertility of 5-year duration due to frozen pelvis secondary to endometriosis. RESULTS: Following controlled ovarian hyperstimulation, oocyte recovery and fertilization, cleavage and transfer of two zygotes, a pregnancy established. A twin gestation was diagnosed at 7-weeks scan and pregnancy ended with the delivery of twin girls by emergency caesarean section. CONCLUSION: This is a first report of a delivery following IVF using the antagonist protocol in Ireland. Such therapy is patient friendly and its use should be introduced on a larger scale in clinical practice.

  4. Histamine-2 receptor antagonists as immunomodulators: new therapeutic views?

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen

    1996-01-01

    of proliferation and angiogenesis. Specific histamine receptors have been identified on the surface of bone marrow cells, immune competent cells, endothelial cells, fibroblasts, and also on malignant cells. This has prompted research in regulation by specific histamine receptor agonists and antagonists. Results...... from such studies are currently accumulating and suggest that the histamine-2 receptor antagonists have potential beneficial effects in the treatment of certain malignant, autoimmune and skin diseases, either alone or in combination with other drugs. The beneficial effect of histamine-2 receptor...... antagonists as adjuvant single drugs to reduce trauma-, blood transfusion- and sepsis-induced immunosuppression has led to research in combined treatment regimens in major surgery, particularly, of patients operated on for malignant diseases....

  5. GnRH antagonist versus long agonist protocols in IVF

    DEFF Research Database (Denmark)

    Lambalk, C B; Banga, F R; Huirne, J A

    2017-01-01

    was not the only variable between the compared study arms. OBJECTIVE AND RATIONALE: The aim of the current study was to compare GnRH antagonist protocols versus standard long agonist protocols in couples undergoing IVF or ICSI, while accounting for various patient populations and treatment schedules. SEARCH......BACKGROUND: Most reviews of IVF ovarian stimulation protocols have insufficiently accounted for various patient populations, such as ovulatory women, women with polycystic ovary syndrome (PCOS) or women with poor ovarian response, and have included studies in which the agonist or antagonist...... METHODS: The Cochrane Menstrual Disorders and Subfertility Review Group specialized register of controlled trials and Pubmed and Embase databases were searched from inception until June 2016. Eligible trials were those that compared GnRH antagonist protocols and standard long GnRH agonist protocols...

  6. ANTAGONISTIC BACTERIA AGAINST SCHIZOPHYLLUM COMMUNE FR. IN PENINSULAR MALAYSIA

    Directory of Open Access Journals (Sweden)

    ANTARJO DIKIN

    2006-01-01

    Full Text Available Schizophyllum commune Fr., is one of the important fungi, causes brown germ and seed rot of oil palm. Biodiversity of antagonistic bacteria from oil palm plantations in Peninsular Malaysia is expected to support in development of biopesticide. Isolation with liquid assay and screening antagonistic bacteria using dual culture assay were carried out in the bioexploration. A total of 265 bacterial isolates from plant parts of oil palm screened 52 antagonistic bacterial isolates against 5. commune. Bacterial isolates were identified by using Biolog* Identification System i.e. Bacillus macroccanus, B. thermoglucosidasius, Burkholderia cepacia, B. gladioli, B. multivorans, B pyrrocinia, B. spinosa, Corynebacterium agropyri, C. misitidis, Enterobacter aerogenes, Microbacterium testaceum, Pseudomonas aeruginosa, P. citronellolis, Rhodococcus rhodochrous, Serratia ficaria, Serratia sp., S. marcescens, Staphylococcus sciuri, Sternotrophomonas maltophilia.

  7. Histamine H4 receptor antagonists: the new antihistamines?

    Science.gov (United States)

    Fung-Leung, Wai-Ping; Thurmond, Robin L; Ling, Ping; Karlsson, Lars

    2004-11-01

    Antihistamines (histamine H1 receptor antagonists) are a mainstay treatment for atopic allergy, yet they are only partially effective in relieving the symptoms of the disease. They also have very limited value for the treatment of asthma, despite the well-characterized bronchoconstrictory effects of histamine. The recent discovery of a fourth histamine receptor (H4), and the realization that it is exclusively expressed on hematopoietic cell types that are most implicated in the development and symptomatology of allergy and asthma, suggests that pharmacological targeting of the H4 receptor, either alone or in combination with H1 receptor antagonists, may prove useful for treating both allergy and asthma. Here we review the known biology associated with the H4 receptor, as well the effects of a highly selective H1 receptor antagonist.

  8. Calcitonin gene-related peptide does not cause the familial hemiplegic migraine phenotype

    DEFF Research Database (Denmark)

    Hansen, J.M.; Thomsen, L.L.; Olesen, J.

    2008-01-01

    Objective: The neuropeptide calcitonin gene-related peptide (CGRP) is a migraine trigger that plays a crucial role in migraine pathophysiology, and CGRP antagonism is efficient in the treatment of migraine attacks. Familial hemiplegic migraine (FHM) is a dominantly inherited subtype of migraine w...... without aura. This indicates that the pathophysiologic pathways underlying migraine headache in FHM may be different from the common types of migraine and questions whether CGRP antagonists would be effective in the treatment of FHM patients Udgivelsesdato: 2008/9/9...

  9. Spadin, a Sortilin-derived peptide: a new concept in the antidepressant drug design

    Directory of Open Access Journals (Sweden)

    Heurteaux Catherine

    2011-07-01

    Full Text Available Depression is the most common of psychiatric illnesses. The design of effective treatments for this disorder is a challenging process. Recently, the two-pore domain potassium channel TREK-1 has been identified as a new target in depression, and its antagonists might become effective antidepressants. Deletion of TREK-1 gene results in a depression-resistant phenotype that mimics antidepressant treatments. Here, we validate the fast antidepressant effects of spadin, a secreted peptide derived from the propeptide generated by the maturation of the sortilin receptor and acting through TREK-1 inhibition.

  10. Clinical Development of Histamine H4Receptor Antagonists.

    Science.gov (United States)

    Thurmond, Robin L; Venable, Jennifer; Savall, Brad; La, David; Snook, Sandra; Dunford, Paul J; Edwards, James P

    2017-01-01

    The discovery of the histamine H 4 receptor (H 4 R) provided a new avenue for the exploration of the physiological role of histamine, as well as providing a new drug target for the development of novel antihistamines. The first step in this process was the identification of selective antagonists to help unravel the pharmacology of the H 4 R relative to other histamine receptors. The discovery of the selective H 4 R antagonist JNJ 7777120 was vital for showing a role for the H 4 R in inflammation and pruritus. While this compound has been very successful as a tool for understanding the function of the receptor, it has drawbacks, including a short in vivo half-life and hypoadrenocorticism toxicity in rats and dogs, that prevented advancing it into clinical studies. Further research let to the discovery of JNJ 39758979, which, similar to JNJ 7777120, was a potent and selective H 4 R antagonist and showed anti-inflammatory and anti-pruritic activity preclinically. JNJ 39758979 advanced into human clinical studies and showed efficacy in reducing experimental pruritus and in patients with atopic dermatitis. However, development of this compound was terminated due to the occurrence of drug-induced agranulocytosis. This was overcome by developing another H 4 R antagonist with a different chemical structure, toreforant, that does not appear to have this side effect. Toreforant has been tested in clinical studies in patients with rheumatoid arthritis, asthma, or psoriasis. In conclusions there have been many H 4 R antagonists reported in the literature, but only a few have been studied in humans underscoring the difficulty in finding ligands with all of the properties necessary for testing in the clinic. Nevertheless, the clinical data to date suggests that H 4 R antagonists can be beneficial in treating atopic dermatitis and pruritus.

  11. Progesterone receptor isoforms, agonists and antagonists differentially reprogram estrogen signaling.

    Science.gov (United States)

    Singhal, Hari; Greene, Marianne E; Zarnke, Allison L; Laine, Muriel; Al Abosy, Rose; Chang, Ya-Fang; Dembo, Anna G; Schoenfelt, Kelly; Vadhi, Raga; Qiu, Xintao; Rao, Prakash; Santhamma, Bindu; Nair, Hareesh B; Nickisch, Klaus J; Long, Henry W; Becker, Lev; Brown, Myles; Greene, Geoffrey L

    2018-01-12

    Major roadblocks to developing effective progesterone receptor (PR)-targeted therapies in breast cancer include the lack of highly-specific PR modulators, a poor understanding of the pro- or anti-tumorigenic networks for PR isoforms and ligands, and an incomplete understanding of the cross talk between PR and estrogen receptor (ER) signaling. Through genomic analyses of xenografts treated with various clinically-relevant ER and PR-targeting drugs, we describe how the activation or inhibition of PR differentially reprograms estrogen signaling, resulting in the segregation of transcriptomes into separate PR agonist and antagonist-mediated groups. These findings address an ongoing controversy regarding the clinical utility of PR agonists and antagonists, alone or in combination with tamoxifen, for breast cancer management. Additionally, the two PR isoforms PRA and PRB, bind distinct but overlapping genomic sites and interact with different sets of co-regulators to differentially modulate estrogen signaling to be either pro- or anti-tumorigenic. Of the two isoforms, PRA inhibited gene expression and ER chromatin binding significantly more than PRB. Differential gene expression was observed in PRA and PRB-rich patient tumors and PRA-rich gene signatures had poorer survival outcomes. In support of antiprogestin responsiveness of PRA-rich tumors, gene signatures associated with PR antagonists, but not PR agonists, predicted better survival outcomes. The better patient survival associated with PR antagonists versus PR agonists treatments was further reflected in the higher in vivo anti-tumor activity of therapies that combine tamoxifen with PR antagonists and modulators. This study suggests that distinguishing common effects observed due to concomitant interaction of another receptor with its ligand (agonist or antagonist), from unique isoform and ligand-specific effects will inform the development of biomarkers for patient selection and translation of PR

  12. Progesterone receptor isoforms, agonists and antagonists differentially reprogram estrogen signaling

    Science.gov (United States)

    Singhal, Hari; Greene, Marianne E.; Zarnke, Allison L.; Laine, Muriel; Al Abosy, Rose; Chang, Ya-Fang; Dembo, Anna G.; Schoenfelt, Kelly; Vadhi, Raga; Qiu, Xintao; Rao, Prakash; Santhamma, Bindu; Nair, Hareesh B.; Nickisch, Klaus J.; Long, Henry W.; Becker, Lev; Brown, Myles; Greene, Geoffrey L.

    2018-01-01

    Major roadblocks to developing effective progesterone receptor (PR)-targeted therapies in breast cancer include the lack of highly-specific PR modulators, a poor understanding of the pro- or anti-tumorigenic networks for PR isoforms and ligands, and an incomplete understanding of the cross talk between PR and estrogen receptor (ER) signaling. Through genomic analyses of xenografts treated with various clinically-relevant ER and PR-targeting drugs, we describe how the activation or inhibition of PR differentially reprograms estrogen signaling, resulting in the segregation of transcriptomes into separate PR agonist and antagonist-mediated groups. These findings address an ongoing controversy regarding the clinical utility of PR agonists and antagonists, alone or in combination with tamoxifen, for breast cancer management. Additionally, the two PR isoforms PRA and PRB, bind distinct but overlapping genomic sites and interact with different sets of co-regulators to differentially modulate estrogen signaling to be either pro- or anti-tumorigenic. Of the two isoforms, PRA inhibited gene expression and ER chromatin binding significantly more than PRB. Differential gene expression was observed in PRA and PRB-rich patient tumors and PRA-rich gene signatures had poorer survival outcomes. In support of antiprogestin responsiveness of PRA-rich tumors, gene signatures associated with PR antagonists, but not PR agonists, predicted better survival outcomes. The better patient survival associated with PR antagonists versus PR agonists treatments was further reflected in the higher in vivo anti-tumor activity of therapies that combine tamoxifen with PR antagonists and modulators. This study suggests that distinguishing common effects observed due to concomitant interaction of another receptor with its ligand (agonist or antagonist), from unique isoform and ligand-specific effects will inform the development of biomarkers for patient selection and translation of PR

  13. Endothelin receptor antagonists influence cardiovascular morphology in uremic rats.

    Science.gov (United States)

    Nabokov, A V; Amann, K; Wessels, S; Münter, K; Wagner, J; Ritz, E

    1999-02-01

    In is generally held that renal failure results in blood pressure (BP)-independent structural changes of the myocardium and the vasculature. The contribution, if any, of endothelin (ET) to these changes has been unknown. We morphometrically studied random samples of the left ventricle myocardium and small intramyocardial arteries in subtotally (5/6) nephrectomized (SNx) male Sprague-Dawley rats treated with either the selective ETA receptor antagonist BMS182874 (30 mg/kg/day) or the nonselective ETA/ETB receptor antagonist Ro46-2005 (30 mg/kg/day) in comparison with either sham-operated rats, untreated SNx, or SNx rats treated with the angiotensin-converting enzyme inhibitor trandolapril (0.1 mg/kg/day). Eight weeks later, systolic BP was lower in trandolapril-treated SNx compared with untreated SNx animals. No decrease in BP was seen following either ET receptor antagonist at the dose used. A significantly increased volume density of the myocardial interstitium was found in untreated SNx rats as compared with sham-operated controls. Such interstitial expansion was prevented by trandolapril and either ET receptor antagonist. SNx caused a substantial increase in the wall thickness of small intramyocardial arteries. The increase was prevented by trandolapril or BMS182874 treatment. The arteriolar wall:lumen ratio was significantly lower in all treated groups when compared with untreated SNx. In contrast, only trandolapril, but not the ET receptor antagonists, attenuated thickening of the aortic media in SNx animals. The ETA-selective and ETA/ETB-nonselective receptor antagonists appear to prevent development of myocardial fibrosis and structural changes of small intramyocardial arteries in experimental chronic renal failure. This effect is independent of systemic BP.

  14. Improving the Fmoc Solid Phase Synthesis of the Cyclic Hexapeptide Complement C5a Antagonist, PMX205.

    Science.gov (United States)

    Delisle Milton, R C; Milton, S C; Chamberlin, A R

    2011-12-01

    The anti-inflammatory drug, PMX205, is an antagonist of the C5a complement receptor and has been shown to be effective in rodent models of amyotrophic lateral sclerosis and Alzheimer's disease. This cyclic hexapeptide (c[Arg-Trp-D-Cha-Pro-Orn]-Hca) has been reported to produce relatively low yields for both the linear peptide assembly and the cyclization reaction in solution and solid phase syntheses. During attempts to reproduce the solid phase methodology, a catastrophic loss of substitution was encountered which could be avoided or reduced by the use of 2-chlorotrityl resin. Likewise, the cyclization reaction could be significantly improved by the use of FDPP (pentafluorophenyl diphenylphosphinate) at high dilution (up to 80% purified yield). Both improvements are accomplished with commercially available products.

  15. Discovery of Tertiary Sulfonamides as Potent Liver X Receptor Antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Zuercher, William J.; Buckholz†, Richard G.; Campobasso, Nino; Collins, Jon L.; Galardi, Cristin M.; Gampe, Robert T.; Hyatt, Stephen M.; Merrihew, Susan L.; Moore, John T.; Oplinger, Jeffrey A.; Reid, Paul R.; Spearing, Paul K.; Stanley, Thomas B.; Stewart, Eugene L.; Willson, Timothy M. (GSKNC)

    2010-08-12

    Tertiary sulfonamides were identified in a HTS as dual liver X receptor (LXR, NR1H2, and NR1H3) ligands, and the binding affinity of the series was increased through iterative analogue synthesis. A ligand-bound cocrystal structure was determined which elucidated key interactions for high binding affinity. Further characterization of the tertiary sulfonamide series led to the identification of high affinity LXR antagonists. GSK2033 (17) is the first potent cell-active LXR antagonist described to date. 17 may be a useful chemical probe to explore the cell biology of this orphan nuclear receptor.

  16. Interleukin-1-receptor antagonist in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Larsen, Claus M; Faulenbach, Mirjam; Vaag, Allan

    2007-01-01

    BACKGROUND: The expression of interleukin-1-receptor antagonist is reduced in pancreatic islets of patients with type 2 diabetes mellitus, and high glucose concentrations induce the production of interleukin-1beta in human pancreatic beta cells, leading to impaired insulin secretion, decreased cell...... proliferation, and apoptosis. METHODS: In this double-blind, parallel-group trial involving 70 patients with type 2 diabetes, we randomly assigned 34 patients to receive 100 mg of anakinra (a recombinant human interleukin-1-receptor antagonist) subcutaneously once daily for 13 weeks and 36 patients to receive...

  17. Characterization of Synthetic Peptides by Mass Spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala K; Mirza, Osman; Højrup, Peter

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI-TOF-MS an......Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI...

  18. Pituitary adenylate cyclase-activating peptide stimulates neurite growth in PC12 cells.

    Science.gov (United States)

    Hernandez, A; Kimball, B; Romanchuk, G; Mulholland, M W

    1995-01-01

    The ability of PACAP-38 to stimulate morphological development was studied using rat pheochromocytoma PC12 cells. PACAP-38 produced concentration-dependent increases in percentage of cells exhibiting neurite extension. Similar increases were produced by forskolin (28 +/- 2% at 96 h) and 8-bromo cAMP (30 +/- 2%). Vasoactive intestinal peptide and alpha-calcitonin gene-related peptide were without effect. PACAP-38 produced significant increases in PC12 cell cAMP content and inositol phosphate turnover. Intracellular [Ca2+] increased from 169 +/- 14 nM to 560 +/- 58 nM in response to 1 microM PACAP-38. PACAP-stimulated neurite outgrowth was abolished by RpcAMPS, an inhibitor of cAMP-dependent kinases but was unaffected by the protein kinase C antagonist H7.

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

    Directory of Open Access Journals (Sweden)

    Francis S. Willard

    2012-01-01

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

  20. Peptides identify multiple hotspots within the ligand binding domain of the TNF receptor 2

    Directory of Open Access Journals (Sweden)

    Lennick Michael

    2003-01-01

    Full Text Available Abstract Background Hotspots are defined as the minimal functional domains involved in protein:protein interactions and sufficient to induce a biological response. Results Here we describe the use of complex and high diversity phage display libraries to isolate peptides (called Hotspot Ligands or HSPLs which sub-divide the ligand binding domain of the tumor necrosis factor receptor 2 (TNFR2; p75 into multiple hotspots. We have shown that these libraries could generate HSPLs which not only subdivide hotspots on protein and non-protein targets but act as agonists or antagonists. Using this approach, we generated peptides which were specific for human TNFR2, could be competed by the natural ligands, TNFα and TNFβ and induced an unexpected biological response in a TNFR2-specific manner. Conclusions To our knowledge, this is the first report describing the dissection of the TNFR2 into biologically active hotspots with the concomitant identification of a novel and unexpected biological activity.

  1. Antiviral active peptide from oyster

    Science.gov (United States)

    Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

    2008-08-01

    An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

  2. Dietary bioactive peptides: Human studies.

    Science.gov (United States)

    Bouglé, Dominique; Bouhallab, Saïd

    2017-01-22

    Current opinion strongly links nutrition and health. Among nutrients, proteins, and peptides which are encrypted in their sequences and released during digestion could play a key role in improving health. These peptides have been claimed to be active on a wide spectrum of biological functions or diseases, including blood pressure and metabolic risk factors (coagulation, obesity, lipoprotein metabolism, and peroxidation), gut and neurological functions, immunity, cancer, dental health, and mineral metabolism. A majority of studies involved dairy peptides, but the properties of vegetal, animal, and sea products were also assessed. However, these allegations are mainly based on in vitro and experimental studies which are seldom confirmed in humans. This review focused on molecules which were tested in humans, and on the mechanisms explaining discrepancies between experimental and human studies.

  3. S961, an insulin receptor antagonist causes hyperinsulinemia, insulin-resistance and depletion of energy stores in rats

    Energy Technology Data Exchange (ETDEWEB)

    Vikram, Ajit [Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, Mohali, Punjab 160 062 (India); Jena, Gopabandhu, E-mail: gbjena@gmail.com [Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, Mohali, Punjab 160 062 (India)

    2010-07-23

    Research highlights: {yields}Insulin receptor antagonist S961 causes hyperglycemia, hyperinsulinemia and insulin resistance in rats. {yields}Peroxysome-proliferator-activated-receptor-gamma agonist pioglitazone improves S961 induced hyperglycemia and glucose intolerance. {yields}Long term treatment with insulin receptor antagonist S961 results in the decreased adiposity and hepatic glycogen content. {yields}Improvement in the hyperglycemia and glucose intolerance by pioglitazone clearly demonstrates that S961 treated rats can be successfully used to screen the novel therapeutic interventions having potential to improve glucose disposal through receptor independent mechanisms. -- Abstract: Impairment in the insulin receptor signaling and insulin mediated effects are the key features of type 2 diabetes. Here we report that S961, a peptide insulin receptor antagonist induces hyperglycemia, hyperinsulinemia ({approx}18-fold), glucose intolerance and impairment in the insulin mediated glucose disposal in the Sprague-Dawley rats. Further, long-term S961 treatment (15 day, 10 nM/kg/day) depletes energy storage as evident from decrease in the adiposity and hepatic glycogen content. However, peroxysome-proliferator-activated-receptor-gamma (PPAR{gamma}) agonist pioglitazone significantly (P < 0.001) restored S961 induced hyperglycemia (196.73 {+-} 16.32 vs. 126.37 {+-} 27.07 mg/dl) and glucose intolerance ({approx}78%). Improvement in the hyperglycemia and glucose intolerance by pioglitazone clearly demonstrates that S961 treated rats can be successfully used to screen the novel therapeutic interventions having potential to improve glucose disposal through receptor independent mechanisms. Further, results of the present study reconfirms and provide direct evidence to the crucial role of insulin receptor signaling in the glucose homeostasis and fuel metabolism.

  4. S961, an insulin receptor antagonist causes hyperinsulinemia, insulin-resistance and depletion of energy stores in rats

    International Nuclear Information System (INIS)

    Vikram, Ajit; Jena, Gopabandhu

    2010-01-01

    Research highlights: →Insulin receptor antagonist S961 causes hyperglycemia, hyperinsulinemia and insulin resistance in rats. →Peroxysome-proliferator-activated-receptor-gamma agonist pioglitazone improves S961 induced hyperglycemia and glucose intolerance. →Long term treatment with insulin receptor antagonist S961 results in the decreased adiposity and hepatic glycogen content. →Improvement in the hyperglycemia and glucose intolerance by pioglitazone clearly demonstrates that S961 treated rats can be successfully used to screen the novel therapeutic interventions having potential to improve glucose disposal through receptor independent mechanisms. -- Abstract: Impairment in the insulin receptor signaling and insulin mediated effects are the key features of type 2 diabetes. Here we report that S961, a peptide insulin receptor antagonist induces hyperglycemia, hyperinsulinemia (∼18-fold), glucose intolerance and impairment in the insulin mediated glucose disposal in the Sprague-Dawley rats. Further, long-term S961 treatment (15 day, 10 nM/kg/day) depletes energy storage as evident from decrease in the adiposity and hepatic glycogen content. However, peroxysome-proliferator-activated-receptor-gamma (PPARγ) agonist pioglitazone significantly (P < 0.001) restored S961 induced hyperglycemia (196.73 ± 16.32 vs. 126.37 ± 27.07 mg/dl) and glucose intolerance (∼78%). Improvement in the hyperglycemia and glucose intolerance by pioglitazone clearly demonstrates that S961 treated rats can be successfully used to screen the novel therapeutic interventions having potential to improve glucose disposal through receptor independent mechanisms. Further, results of the present study reconfirms and provide direct evidence to the crucial role of insulin receptor signaling in the glucose homeostasis and fuel metabolism.

  5. A trimeric structural fusion of an antagonistic tumor necrosis factor-α mutant enhances molecular stability and enables facile modification.

    Science.gov (United States)

    Inoue, Masaki; Ando, Daisuke; Kamada, Haruhiko; Taki, Shintaro; Niiyama, Mayumi; Mukai, Yohei; Tadokoro, Takashi; Maenaka, Katsumi; Nakayama, Taisuke; Kado, Yuji; Inoue, Tsuyoshi; Tsutsumi, Yasuo; Tsunoda, Shin-Ichi

    2017-04-21

    Tumor necrosis factor-α (TNF) exerts its biological effect through two types of receptors, p55 TNF receptor (TNFR1) and p75 TNF receptor (TNFR2). An inflammatory response is known to be induced mainly by TNFR1, whereas an anti-inflammatory reaction is thought to be mediated by TNFR2 in some autoimmune diseases. We have been investigating the use of an antagonistic TNF mutant (TNFR1-selective antagonistic TNF mutant (R1antTNF)) to reveal the pharmacological effect of TNFR1-selective inhibition as a new therapeutic modality. Here, we aimed to further improve and optimize the activity and behavior of this mutant protein both in vitro and in vivo Specifically, we examined a trimeric structural fusion of R1antTNF, formed via the introduction of short peptide linkers, as a strategy to enhance bioactivity and molecular stability. By comparative analysis with R1antTNF, the trimeric fusion, referred to as single-chain R1antTNF (scR1antTNF), was found to retain in vitro molecular properties of receptor selectivity and antagonistic activity but displayed a marked increase in thermal stability. The residence time of scR1antTNF in vivo was also significantly prolonged. Furthermore, molecular modification using polyethylene glycol (PEG) was easily controlled by limiting the number of reactive sites. Taken together, our findings show that scR1antTNF displays enhanced molecular stability while maintaining biological activity compared with R1antTNF. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Medicinal Chemistry, Pharmacology, and Clinical Implications of TRPV1 Receptor Antagonists.

    Science.gov (United States)

    Aghazadeh Tabrizi, Mojgan; Baraldi, Pier Giovanni; Baraldi, Stefania; Gessi, Stefania; Merighi, Stefania; Borea, Pier Andrea

    2017-07-01

    Transient receptor potential vanilloid 1 (TRPV1) is an ion channel expressed on sensory neurons triggering an influx of cations. TRPV1 receptors function as homotetramers responsive to heat, proinflammatory substances, lipoxygenase products, resiniferatoxin, endocannabinoids, protons, and peptide toxins. Its phosphorylation increases sensitivity to both chemical and thermal stimuli, while desensitization involves a calcium-dependent mechanism resulting in receptor dephosphorylation. TRPV1 functions as a sensor of noxious stimuli and may represent a target to avoid pain and injury. TRPV1 activation has been associated to chronic inflammatory pain and peripheral neuropathy. Its expression is also detected in nonneuronal areas such as bladder, lungs, and cochlea where TRPV1 activation is responsible for pathology development of cystitis, asthma, and hearing loss. This review offers a comprehensive overview about TRPV1 receptor in the pathophysiology of chronic pain, epilepsy, cough, bladder disorders, diabetes, obesity, and hearing loss, highlighting how drug development targeting this channel could have a clinical therapeutic potential. Furthermore, it summarizes the advances of medicinal chemistry research leading to the identification of highly selective TRPV1 antagonists and their analysis of structure-activity relationships (SARs) focusing on new strategies to target this channel. © 2016 Wiley Periodicals, Inc.

  7. Endothelin receptor antagonist prevents parathyroid cell proliferation of low calcium diet-induced hyperparathyroidism in rats.

    Science.gov (United States)

    Kanesaka, Y; Tokunaga, H; Iwashita, K; Fujimura, S; Naomi, S; Tomita, K

    2001-01-01

    Secondary hyperparathyroidism, one of the most frequently encountered disorders of the calcium homeostasis, is characterized by an increase in parathyroid epithelial (PT) cell number, which is crucial from a functional viewpoint. However, it is still unknown what factors are involved in PT cell proliferation. Endothelin-1 (ET-1), a vasoconstrictive peptide, has been shown to act as a mitogen in a variety of cell types. Rat PT cells are reported to synthesize ET-1 and possess its receptors. To test the hypothesis that ET-1 plays a role in PT cell proliferation, we used rat test subjects fed a low calcium diet for 8 weeks (low Ca rats). The number of the proliferating PT cells, measured by proliferating cell nuclear antigen immunostaining, was significantly increased, with striking immunoreactivity of ET-1 in the low Ca rats. An endothelin receptor antagonist, bosentan (100 mg/kg.day), prevented any increase in the proliferation of PT cells in the low Ca rats (14.3 +/- 2.7/1000 PT cells with no bosentan; 2.1 +/- 1.3 with bosentan; P hyperparathyroidism.

  8. Identification and characterization of novel surfactins produced by fungal antagonist Bacillus amyloliquefaciens 6B.

    Science.gov (United States)

    Pathak, Khyati V; Bose, Anjali; Keharia, Haresh

    2014-01-01

    The broad-spectrum fungal antagonist, Bacillus amyloliquefaciens 6B (BA6B), isolated from the Jakhao coast of Kutch, India, was investigated for its antifungal metabolites using mass spectrometry. The cyclic lipopeptides harvested from the cell-free fermentation broth of BA6B by acid precipitation and subsequently dissolved in methanol were subjected to liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS/MS) for their identification and sequence determination. The 26 types of surfactin variants were identified from the methanolic extract by LC-ESI-MS/MS analysis. Among 26 surfactin species, several new cyclic as well as acyclic surfactin variants based on the variation in the β-hydroxy fatty acid (β-OH FA) chain length and/or in amino acid positions 4, 5, 6, and 7 were identified. The mass spectrometric analysis of crude extract also enabled the identification of 11 unique molecular mass ions with minimum two or maximum four types of isobaric peptide variants. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  9. Identification of VDR Antagonists among Nuclear Receptor Ligands Using Virtual Screening

    Directory of Open Access Journals (Sweden)

    Kelly Teske

    2014-04-01

    Full Text Available Herein, we described the development of two virtual screens to identify new vitamin D receptor (VDR antagonists among nuclear receptor (NR ligands. Therefore, a database of 14330 nuclear receptor ligands and their NR affinities was assembled using the online available “Binding Database.” Two different virtual screens were carried out in conjunction with a reported VDR crystal structure applying a stringent and less stringent pharmacophore model to filter docked NR ligand conformations. The pharmacophore models were based on the spatial orientation of the hydroxyl functionalities of VDR's natural ligands 1,25(OH2D3 and 25(OH2D3. The first virtual screen identified 32 NR ligands with a calculated free energy of VDR binding of more than -6.0 kJ/mol. All but nordihydroguaiaretic acid (NDGA are VDR ligands, which inhibited the interaction between VDR and coactivator peptide SRC2-3 with an IC50 value of 15.8 μM. The second screen identified 162 NR ligands with a calculated free energy of VDR binding of more than -6.0 kJ/mol. More than half of these ligands were developed to bind VDR followed by ERα/β ligands (26%, TRα/β ligands (7%, and LxRα/β ligands (7%. The binding between VDR and ERα ligand H6036 as well as TRα/β ligand triiodothyronine and a homoserine analog thereof was confirmed by fluorescence polarization.

  10. Endothelin receptor antagonist attenuates oxidative stress in a neonatal sepsis piglet model.

    Science.gov (United States)

    Goto, Tatenobu; Hussein, Mohamed Hamed; Kato, Shin; Daoud, Ghada Abdel-Hamid; Kato, Takenori; Sugiura, Takahiro; Kakita, Hiroki; Nobata, Masanori; Kamei, Michi; Mizuno, Haruo; Imai, Masaki; Ito, Tetsuya; Kato, Ineko; Suzuki, Satoshi; Okada, Noriko; Togari, Hajime; Okada, Hidechika

    2012-12-01

    Oxidative stress (oxidant-antioxidant imbalance) plays an important role in the pathophysiology of neonatal sepsis. This study evaluated whether an antisense peptide endothelin receptor antagonist, ETR-P1/fl, could attenuate oxidative stress in a neonatal sepsis model. A total of 18 3-d-old piglets were anesthetized and mechanically ventilated. Six piglets received cecal ligation and perforation (CLP group) for induction of sepsis. Six piglets also received continuous infusion (0.05 mg/kg/h) of ETR-P1/fl 30 min after CLP (ETR-P1/fl group). Six piglets received a sham operation. Serum total hydroperoxide (TH), biological antioxidant potentials (BAPs), oxidative stress index (OSI, calculated as TH/BAP), interleukin (IL)-6, serum glutamic oxaloacetic transaminase (GOT), and creatinine were measured before CLP and at 1, 3, and 6 h after CLP. CLP evoked a state of shock resulting in elevated TH, OSI, and IL-6 levels. ETR-P1/fl administration after CLP resulted in lower serum TH at 1 and 3 h after CLP, OSI at 1 and 3 h after CLP, IL-6 at 1 and 3 h after CLP, and GOT at 3 and 6 h after CLP as compared with the CLP group. ETR-P1/fl treatment significantly attenuated the elevation of serum oxidative stress markers (TH and OSI), IL-6, and GOT in a progressive neonatal sepsis CLP model.

  11. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  12. Novel Formulations for Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2014-10-01

    Full Text Available Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.

  13. Biodegradable Peptide-Silica Nanodonuts.

    Science.gov (United States)

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-07

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. First plasma and tissue pharmacokinetic study of the YSNSG cyclopeptide, a new integrin antagonist, using microdialysis.

    Science.gov (United States)

    Slimano, Florian; Djerada, Zoubir; Bouchene, Salim; Van Gulick, Laurence; Brassart-Pasco, Sylvie; Dukic, Sylvain

    2017-07-15

    The YSNSG peptide is a synthetic peptide targeting α v β 3 integrin. This peptide exhibits promising activity in vitro and in vivo against melanoma. To determine pharmacokinetic parameters and predictive active doses in the central nervous system (CNS) and subcutaneous tissue (SC), we conducted microdialysis coupled with pharmacokinetic modeling and Monte Carlo simulation. After a recovery period of surgical procedures, a microdialysis probe was inserted in the caudate and in subcutaneous tissue. Plasma samples and dialysates collected 5h after YSNSG intravenous administration (10mg/kg) were analyzed by UPLC-MS/MS. A nonlinear mixed-effect modeling approach implemented in Monolix® 2016R1 was performed. Model selection and evaluation were based on the usual diagnostic plot, precision and information criteria. The primary plasma and tissue pharmacokinetic parameters were comparable with those of other integrin antagonists, such as cilengitide or ATN-161. Tissue/plasma and brain/plasma area under the curve (AUC) ratio were 66.2±21.6% and 3.6±4.7%, respectively. Two models of 2-compartments with an additional microdialysis compartment, parameterized as rate constants (k for elimination, k12/k21 and k13/k31 for distribution) and volumes (central V1 and peripheral microdialysis compartment V3) with zero-order input were selected to describe the dialysate concentrations in CNS and SC. The inter-individual variability (IIV) was described by exponential terms, and residual variability was described by a combined additive and proportional error model. Individual AUC (plasma and tissues) values were derived for each animal using the Empirical-Bayes-Estimates of the individual parameters. The regimens needed to achieve an in vitro predetermined target concentration in tissues were studied by Monte Carlo simulations using Monolix® 2016R1. YSNSG pharmacokinetic parameters show promising results in terms of subcutaneous disposition. Further investigations into such

  15. Indications for the use of parenteral H2-receptor antagonists.

    Science.gov (United States)

    Thompson, J C; Walker, J P

    1984-11-19

    Development of acute mucosal ulceration is a complex series of catabolic interactions. Hospitalized patients with duodenal or gastric ulcer, pathologic gastric hypersecretory states (such as Zollinger-Ellison syndrome), gastric outlet obstruction, esophagitis, severe gastritis or duodenitis, sepsis, trauma (particularly head injury or burns), and some patients receiving high-dose corticosteroids are at risk of developing acute stress ulcers. Treatment should be initiated as soon as the patient is identified as being at risk, because measures designed to prevent bleeding or perforation are more effective than those designed to stop bleeding once it supervenes and the cascade of multiple organ failure commences. The presence of acid will trigger the onset of this condition; however, ulceration will not occur if the intraluminal pH can be maintained above 5 by periodic antacid treatment or by H2-receptor blockade. The dosing regimen of antacid or of H2-receptor antagonist should not be fixed, but should be sufficient to keep the gastric pH higher than 5. Antagonists administered via a nasogastric tube are the first line of defense, but 30 to 50 percent of the most ill patients will also be treated parenterally with H2-receptor antagonists. Parenteral H2-receptor blockade therapy is indicated in these patients when the risk of acute or continued ulceration of esophageal, gastric, or duodenal mucosa is high and the oral administration of medication is either not possible or the response to such therapy is unreliable. Parenteral H2-receptor antagonists are rarely administered alone.

  16. Bronchoprotection with a leukotriene receptor antagonist in asthmatic preschool children

    DEFF Research Database (Denmark)

    Bisgaard, H; Nielsen, K G

    2000-01-01

    We hypothesized that a leukotriene receptor antagonist (LTRA) could provide bronchoprotection against the cold, dry air-induced response in asthmatic preschool children. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of the specific LTRA montelukast at 5...

  17. Manumycin from a new Streptomyces strain shows antagonistic ...

    African Journals Online (AJOL)

    Manumycin from a new Streptomyces strain shows antagonistic effect against methicillin-resistant Staphylococcus aureus (MRSA)/vancomycin-resistant enterococci (VRE) strains from Korean Hospitals. Yun Hee Choi, Seung Sik Cho, Jaya Ram Simkhada, Chi Nam Seong, Hyo Jeong Lee, Hong Seop Moon, Jin Cheol Yoo ...

  18. Gonadotrophin-releasing hormone antagonists for assisted reproductive technology.

    Science.gov (United States)

    Al-Inany, Hesham G; Youssef, Mohamed A; Ayeleke, Reuben Olugbenga; Brown, Julie; Lam, Wai Sun; Broekmans, Frank J

    2016-04-29

    Gonadotrophin-releasing hormone (GnRH) antagonists can be used to prevent a luteinizing hormone (LH) surge during controlled ovarian hyperstimulation (COH) without the hypo-oestrogenic side-effects, flare-up, or long down-regulation period associated with agonists. The antagonists directly and rapidly inhibit gonadotrophin release within several hours through competitive binding to pituitary GnRH receptors. This property allows their use at any time during the follicular phase. Several different regimens have been described including multiple-dose fixed (0.25 mg daily from day six to seven of stimulation), multiple-dose flexible (0.25 mg daily when leading follicle is 14 to 15 mm), and single-dose (single administration of 3 mg on day 7 to 8 of stimulation) protocols, with or without the addition of an oral contraceptive pill. Further, women receiving antagonists have been shown to have a lower incidence of ovarian hyperstimulation syndrome (OHSS). Assuming comparable clinical outcomes for the antagonist and agonist protocols, these benefits would justify a change from the standard long agonist protocol to antagonist regimens. This is an update of a Cochrane review first published in 2001, and previously updated in 2006 and 2011. To evaluate the effectiveness and safety of gonadotrophin-releasing hormone (GnRH) antagonists compared with the standard long protocol of GnRH agonists for controlled ovarian hyperstimulation in assisted conception cycles. We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched from inception to May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, inception to 28 April 2015), Ovid MEDLINE (1966 to 28 April 2015), EMBASE (1980 to 28 April 2015), PsycINFO (1806 to 28 April 2015), CINAHL (to 28 April 2015) and trial registers to 28 April 2015, and handsearched bibliographies of relevant publications and reviews, and abstracts of major scientific meetings, for

  19. Diversity, distribution, and antagonistic activities of rhizobacteria of Panax notoginseng

    Directory of Open Access Journals (Sweden)

    Ze-Yan Fan

    2016-04-01

    Conclusion: The results suggest that diverse bacteria exist in the P. notoginseng rhizosphere soil, with differences in community in the same field, and antagonistic isolates may be good potential biological control agent for the notoginseng root-rot diseases caused by F. oxysporum, Fusarium solani, and Panax herbarum.

  20. Antagonistic effect of brevicin on Gram positive and Gram negative ...

    African Journals Online (AJOL)

    B. Senthil Kumar

    phylogenetic tree was constructed, based on evolutionary distances that were calculated by following the distance matrix method, using the Phylip package. Preparation and analysis of crude extract of protein (CEP) for their antagonistic activity against food borne pathogens. 24 h old MRS broth culture was prepared and ...

  1. Neuroprotection by NMDA receptor antagonists in a variety of neuropathologies.

    Science.gov (United States)

    Palmer, G C

    2001-09-01

    Because of adverse reactions, early efforts to introduce high affinity competitive or use-dependent NMDA receptor antagonists into patients suffering from stroke, head trauma or epilepsy met with failure. Later it was discovered that both low affinity use-dependent NMDA receptor antagonists and compounds with selective affinity for the NR2B receptor subunit met the criteria for safe administration into patients. Furthermore, these low affinity antagonists exhibit significant mechanistic differences from their higher affinity counterparts. Success of the latter is attested to the ability of the following low affinity compounds to be marketed: 1) Cough suppressant-dextromethorphan (available for decades); 2) Parkinson's disease--amantadine, memantine and budipine; 3) Dementia--memantine; and 4) Epilepsy--felbamate. Moreover, Phase III clinical trials are ongoing with remacemide for epilepsy and Huntington's disease and head trauma for HU-211. A host of compounds are or were under evaluation for the possible treatment of stroke, head trauma, hyperalgesia and various neurodegenerative disorders. Despite the fact that other drugs with associated NMDA receptor mechanisms have reached clinical status, this review focuses only on those competitive and use-dependent NMDA receptor antagonists that reached clinical trails. The ensuing discussions link the in vivo pharmacological investigations that led to the success/mistakes/ failures for eventual testing of promising compounds in the clinic.

  2. Epiminocyclohepta[b]indole analogs as 5-HT6 antagonists

    DEFF Research Database (Denmark)

    Henderson, Alan J; Guzzo, Peter R; Ghosh, Animesh

    2012-01-01

    A new series of epiminocyclohepta[b]indoles with potent 5-HT(6) antagonist activity were discovered and optimized using in vitro protocols. One compound from this series was progressed to advanced pharmacokinetic (PK) studies followed by 5-HT(6) receptor occupancy studies. The compound was found ...

  3. Sympatho-inhibitory properties of various AT1 receptor antagonists

    NARCIS (Netherlands)

    Balt, Jippe C.; Mathy, Marie-Jeanne; Pfaffendorf, Martin; van Zwieten, Peter A.

    2002-01-01

    It is well known that angiotensin II (Ang II) can facilitate the effects of sympathetic neurotransmission. In the present study, using various experimental models, we investigated the inhibitory effects of several Ang II subtype 1 receptor (AT1) antagonists on this Ang II-induced facilitation. We

  4. Management of hyperkalaemia consequent to mineralocorticoid-receptor antagonist therapy

    NARCIS (Netherlands)

    Roscioni, Sara S.; de Zeeuw, Dick; Bakker, Stephan J. L.; Lambers Heerspink, Hiddo J.

    2012-01-01

    Mineralocorticoid-receptor antagonists (MRAs) reduce blood pressure and albuminuria in patients treated with angiotensin-converting-enzyme inhibitors or angiotensin-II-receptor blockers. The use of MRAs, however, is limited by the occurrence of hyperkalaemia, which frequently occurs in patients

  5. Calcium antagonists: a ready prescription for treating infectious diseases?

    Science.gov (United States)

    Clark, Kevin B; Eisenstein, Edward M; Krahl, Scott E

    2013-01-01

    Emergence of new and medically resistant pathogenic microbes continues to escalate toward worldwide public health, wild habitat, and commercial crop and livestock catastrophes. Attempts at solving this problem with sophisticated modern biotechnologies, such as smart vaccines and microbicidal and microbistatic drugs that precisely target parasitic bacteria, fungi, and protozoa, remain promising without major clinical and industrial successes. However, discovery of a more immediate, broad spectrum prophylaxis beyond conventional epidemiological approaches might take no longer than the time required to fill a prescription at your neighborhood pharmacy. Findings from a growing body of research suggest calcium antagonists, long approved and marketed for various human cardiovascular and neurological indications, may produce safe, efficacious antimicrobial effects. As a general category of drugs, calcium antagonists include compounds that disrupt passage of Ca(2+) molecules across cell membranes and walls, sequestration and mobilization of free intracellular Ca(2+), and downstream binding proteins and sensors of Ca(2+)-dependent regulatory pathways important for proper cell function. Administration of calcium antagonists alone at current therapeutically relevant doses and schedules, or with synergistic compounds and additional antimicrobial medications, figures to enhance host immunoprotection by directly altering pathogen infection sequences, life cycles, homeostasis, antibiotic tolerances, and numerous other infective, survival, and reproductive processes. Short of being miracle drugs, calcium antagonists are welcome old drugs with new tricks capable of controlling some of the most virulent and pervasive global infectious diseases of plants, animals, and humans, including Chagas' disease, malaria, and tuberculosis.

  6. Role of muscarinic receptor antagonists in urgency and nocturia

    NARCIS (Netherlands)

    Michel, Martin C.; de La Rosette, Jean J. M. C. H.

    2005-01-01

    The overactive bladder (OAB) syndrome is defined as urgency, with or without urgency incontinence, usually accompanied by frequency and nocturia. Muscarinic receptor antagonists are the most established form of treatment for OAB, but until recently their effectiveness was only confirmed for symptoms

  7. How Hybrid Organizations Turn Antagonistic Assets into Complementarities

    DEFF Research Database (Denmark)

    Hockerts, Kai

    2015-01-01

    This article focuses on people excluded from traditional markets as employees, producers, or consumers on the grounds that they lack the appropriate skills. It describes the processes through which these perceived liabilities can be overcome by so-called hybrid organizations. Hybrids pursue expli...... for complementarities, and by creating demands for antagonistic assets, or by using partnerships....

  8. Effects of calcium antagonists on hypertension and diastolic function ...

    African Journals Online (AJOL)

    Calcium antagonists are known to decrease blood pressure acutely and chronically in hypertensive patients with hypertensive heart disease, and also to improve their systolic function. However, disorders of diastolic function may occur early in hypertensive heart disease. The improvement of diastolic function by nifedipine ...

  9. Contrasting effects of intralocus sexual conflict on sexually antagonistic coevolution

    NARCIS (Netherlands)

    Pennell, Tanya M; de Haas, Freek J H; Morrow, Edward H; van Doorn, G Sander

    2016-01-01

    Evolutionary conflict between the sexes can induce arms races in which males evolve traits that are detrimental to the fitness of their female partners, and vice versa. This interlocus sexual conflict (IRSC) has been proposed as a cause of perpetual intersexual antagonistic coevolution with

  10. Effect of Three Calmodulin Antagonists on Subpopulations of CD44 ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,. International Pharmaceutical ... cancer stem cells. It is not known, however, whether targeting CD44 can alter the fate of cancer stem cells themselves. In this study, the effect of the calmodulin antagonists (N-(10-.

  11. Effects of alpha(1)-adrenoceptor antagonists on male sexual function

    NARCIS (Netherlands)

    van Dijk, Marleen M.; de La Rosette, Jean J. M. C. H.; Michel, Martin C.

    2006-01-01

    alpha(1)-Adrenoceptor antagonists such as alfuzosin, doxazosin, tamsulosin and terazosin are first-line agents for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH), but are only second-line agents (doxazosin and terazosin only) for the treatment of

  12. The Effect of Sympathetic Antagonists on the Antidepressant Action ...

    African Journals Online (AJOL)

    Alprazolam is an anti-anxiety drug shown to be effective in the treatment of depression. In this study, the effect of sympathetic receptor antagonists on alprazolam–induced antidepressant action was studied using a mouse model of forced swimming behavioral despair. The interaction of three sympathetic receptor ...

  13. Evaluation of antagonistic fungi against charcoal rot of sunflower ...

    African Journals Online (AJOL)

    user

    Results showed reduction in disease incidence of charcoal rot on sunflower cultivar G-66 with antagonist, A. flavus (100%) followed by A. niger (64.86%) P. capsulatum (63.79%) and T. viride (31.89%) over control. Decrease in disease incidence over control was 100% where seed was treated with combination of A. niger ...

  14. Non-NMDA receptor antagonist-induced drinking in rat

    Science.gov (United States)

    Xu, Z.; Johnson, A. K.

    1998-01-01

    Glutamate has been implicated in the central control of mechanisms that maintain body fluid homeostasis. The present studies demonstrate that intracerebroventricular (i.c.v.) injections of the non-N-methyl-d-aspartate (NMDA) receptor antagonists 6, 7-dinitroquinoxaline-2,3-dione (DNQX) and 6-cyano-7-nitroquinoxaline-2,3 dione (CNQX) induce drinking in rats. The dipsogenic effect of i.c.v. DNQX was antagonized by the non-NMDA receptor agonist alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). The water intake induced by DNQX was also blocked by pretreatment with a NMDA receptor antagonist, MK-801, but not by angiotensin type 1 (AT1) or acetylcholine muscarinic receptor antagonists (losartan and atropine). The results indicate that non-NMDA receptors may exert a tonic inhibitory effect within brain circuits that control dipsogenic activity and that functional integrity of NMDA receptors may be required for the non-NMDA receptor antagonists to induce water intake. Copyright 1998 Published by Elsevier Science B.V.

  15. NK-1 receptor antagonists as anti-cancer drugs

    Indian Academy of Sciences (India)

    The substance P (SP)/neurokinin (NK)-1 receptor system plays an important role in cancer. SP promotes the proliferation of tumour cells, angiogenesis and the migration of tumour cells. We review the involvement of SP, the NK-1 receptor and NK-1 receptor antagonists in cancer. Tumour cells overexpress NK-1 receptors, ...

  16. About the use of antagonistic bacteria and fungi

    OpenAIRE

    Tilcher, R.; Schmidt, C.; Lorenz, D.; Wolf, G. A.

    2002-01-01

    Microorganisms isolated from the phylloplane of vine and cereal plants inhibiting different phytopathogenic fungi were tested as biological control agents against Plasmopara viticola (downy mildew of grapevine). Based on screening in vitro against Phytophthora infestans, P. parasitica, Pythium ultimum, Botrytis cinerea 62 bacterial isolates were selected for tests with Plasmopara viticola.. Antifungal bacterial strains were assayed for antagonistic activity towards the grapevine dieback fungu...

  17. Antagonistic bioactivity of endophytic strains isolated from Salvia ...

    African Journals Online (AJOL)

    The antibiotic-producing potential of endophytic populations from medical plant of Salvia miltiorrhiza was examined. A total of 63 isolates was screened against five fungal and three bacterial species for the production of antimicrobial compounds. It showed that more isolates was antagonistic to fungi than to bacteria.

  18. Voltage-Gated Calcium Channel Antagonists and Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Bruce Lyeth

    2013-06-01

    Full Text Available Traumatic brain injury (TBI is a leading cause of death and disability in the United States. Despite more than 30 years of research, no pharmacological agents have been identified that improve neurological function following TBI. However, several lines of research described in this review provide support for further development of voltage gated calcium channel (VGCC antagonists as potential therapeutic agents. Following TBI, neurons and astrocytes experience a rapid and sometimes enduring increase in intracellular calcium ([Ca2+]i. These fluxes in [Ca2+]i drive not only apoptotic and necrotic cell death, but also can lead to long-term cell dysfunction in surviving cells. In a limited number of in vitro experiments, both L-type and N-type VGCC antagonists successfully reduced calcium loads as well as neuronal and astrocytic cell death following mechanical injury. In rodent models of TBI, administration of VGCC antagonists reduced cell death and improved cognitive function. It is clear that there is a critical need to find effective therapeutics and rational drug delivery strategies for the management and treatment of TBI, and we believe that further investigation of VGCC antagonists should be pursued before ruling out the possibility of successful translation to the clinic.

  19. Antagonistic potential of fluorescent Pseudomonas and its impact on ...

    African Journals Online (AJOL)

    This study focused on the antagonistic potential of fluorescent Pseudomonas in vitro, and its inoculation effect on growth performance of Lycopersicon esculentum in Fusarium oxysporum and Rhizoctonia solani infested soil. Biochemical characteristics of fluorescent Pseudomonas showed that all ten isolates were positive ...

  20. Vasopressin receptor antagonists: pharmacological tools and potential therapeutic agents

    NARCIS (Netherlands)

    Streefkerk, J. O.; van Zwieten, P. A.

    2006-01-01

    The present survey deals with the development and applications of non-peptidergic vasopressin receptor antagonists. The existence of at least three vasopressin receptors (V(1), V(2) and V(3) respectively) is firmly established. V(1)-receptors play a relevant role in the regulation of vascular tone,

  1. Antagonistic activity of selected strains of Bacillus thuringiensis ...

    African Journals Online (AJOL)

    The aim of this work was to determine, in vitro, the antagonistic effectiveness of 60 strains of Bacillus thuringiensis against damping-off and root and stem rot caused by Rhizoctonia solani. The strains were obtained from the International Collection of Entomopathogenic Bacillus at the FCB-UANL. During the in vitro dual ...

  2. The Effect of Antagonist Muscle Sensory Input on Force Regulation.

    Directory of Open Access Journals (Sweden)

    Tanya Onushko

    Full Text Available The purpose of this study was to understand how stretch-related sensory feedback from an antagonist muscle affects agonist muscle output at different contraction levels in healthy adults. Ten young (25.3 ± 2.4 years, healthy subjects performed constant isometric knee flexion contractions (agonist at 6 torque levels: 5%, 10%, 15%, 20%, 30%, and 40% of their maximal voluntary contraction. For half of the trials, subjects received patellar tendon taps (antagonist sensory feedback during the contraction. We compared error in targeted knee flexion torque and hamstring muscle activity, with and without patellar tendon tapping, across the 6 torque levels. At lower torque levels (5%, 10%, and 15%, subjects produced greater knee torque error following tendon tapping compared with the same torque levels without tendon tapping. In contrast, we did not find any difference in torque output at higher target levels (20%, 30%, and 40% between trials with and without tendon tapping. We also observed a load-dependent increase in the magnitude of agonist muscle activity after tendon taps, with no associated load-dependent increase in agonist and antagonist co-activation, or reflex inhibition from the antagonist tapping. The findings suggest that at relatively low muscle activity there is a deficiency in the ability to correct motor output after sensory disturbances, and cortical centers (versus sub-cortical are likely involved.

  3. Isolation of Fusarium fujikuroi antagonistic bacteria and cloning of its ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... effects of volatile metabolites produced by antagonistic P. fluorescens found in the isolates inhibited growth of F. fujikuroi in vitro. ... secondary metabolites play critical roles in many aspects of bacterium-host interactions. ... Nocardia, Sorangium, Brevibacterium, and Burkholderia. (Mavrodi et al., 2006; ...

  4. 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...... such as structure, accessibility and amino acid composition are crucial. Since small peptides tend not to be immunogenic, it may be necessary to conjugate them to carrier proteins in order to enhance immune presentation. Several strategies for conjugation of peptide-carriers applied for immunization exist...

  5. The intracellular pharmacokinetics of terminally capped peptides.

    NARCIS (Netherlands)

    Ruttekolk, I.R.R.; Witsenburg, J.J.; Glauner, H.B.; Bovee-Geurts, P.H.M.; Ferro, E.S.; Verdurmen, W.P.R.; Brock, R.E.

    2012-01-01

    With significant progress in delivery technologies, peptides and peptidomimetics are receiving increasing attention as potential therapeutics also for intracellular applications. However, analyses of the intracellular behavior of peptides are a challenge; therefore, knowledge on the intracellular

  6. Strategic approaches to optimizing peptide ADME properties.

    Science.gov (United States)

    Di, Li

    2015-01-01

    Development of peptide drugs is challenging but also quite rewarding. Five blockbuster peptide drugs are currently on the market, and six new peptides received first marketing approval as new molecular entities in 2012. Although peptides only represent 2% of the drug market, the market is growing twice as quickly and might soon occupy a larger niche. Natural peptides typically have poor absorption, distribution, metabolism, and excretion (ADME) properties with rapid clearance, short half-life, low permeability, and sometimes low solubility. Strategies have been developed to improve peptide drugability through enhancing permeability, reducing proteolysis and renal clearance, and prolonging half-life. In vivo, in vitro, and in silico tools are available to evaluate ADME properties of peptides, and structural modification strategies are in place to improve peptide developability.

  7. Histidine-Containing Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  8. Tumor Associated Antigenic Peptides in Prostate Cancer

    National Research Council Canada - National Science Library

    Tiwari, Raj

    2001-01-01

    .... Since this tumor rejection property was specifically mediated by tumor denved and not non-tumor derived gp96-peptide complexes, and that gp96 preparations stripped of its peptides are non-immunogenic...

  9. Peptides: Production, bioactivity, functionality, and applications

    DEFF Research Database (Denmark)

    Hajfathalian, Mona; Ghelichi, Sakhi; García Moreno, Pedro Jesús

    2017-01-01

    Production of peptides with various effects from proteins of different sources continues to receive academic attention. Researchers of different disciplines are putting increasing efforts to produce bioactive and functional peptides from different sources such as plants, animals, and food industry...

  10. Do Neuroendocrine Peptides and Their Receptors Qualify as Novel Therapeutic Targets in Osteoarthritis?

    Directory of Open Access Journals (Sweden)

    Susanne Grässel

    2018-01-01

    Full Text Available Joint tissues like synovium, articular cartilage, meniscus and subchondral bone, are targets for neuropeptides. Resident cells of these tissues express receptors for various neuroendocrine-derived peptides including proopiomelanocortin (POMC-derived peptides, i.e., α-melanocyte-stimulating hormone (α-MSH, adrenocorticotropin (ACTH and β-endorphin (β-ED, and sympathetic neuropeptides like vasoactive intestinal peptide (VIP and neuropeptide y (NPY. Melanocortins attained particular attention due to their immunomodulatory and anti-inflammatory effects in several tissues and organs. In particular, α-MSH, ACTH and specific melanocortin-receptor (MCR agonists appear to have promising anti-inflammatory actions demonstrated in animal models of experimentally induced arthritis and osteoarthritis (OA. Sympathetic neuropeptides have obtained increasing attention as they have crucial trophic effects that are critical for joint tissue and bone homeostasis. VIP and NPY are implicated in direct and indirect activation of several anabolic signaling pathways in bone and synovial cells. Additionally, pituitary adenylate cyclase-activating polypeptide (PACAP proved to be chondroprotective and, thus, might be a novel target in OA. Taken together, it appears more and more likely that the anabolic effects of these neuroendocrine peptides or their respective receptor agonists/antagonists may be exploited for the treatment of patients with inflammatory and degenerative joint diseases in the future.

  11. A novel peptide that improves metabolic parameters without adverse central nervous system effects.

    Science.gov (United States)

    Reckziegel, Patrícia; Festuccia, William T; Britto, Luiz R G; Jang, Karen L Lopes; Romão, Carolina M; Heimann, Joel C; Fogaça, Manoela V; Rodrigues, Naielly S; Silva, Nicole R; Guimarães, Francisco S; Eichler, Rosangela A S; Gupta, Achla; Gomes, Ivone; Devi, Lakshmi A; Heimann, Andrea S; Ferro, Emer S

    2017-11-01

    Intracellular peptides generated by limited proteolysis are likely to function inside and outside cells and could represent new possibilities for drug development. Here, we used several conformational-sensitive antibodies targeting G-protein coupled receptors to screen for novel pharmacological active peptides. We find that one of these peptides, DITADDEPLT activates cannabinoid type 1 receptors. Single amino acid modifications identified a novel peptide, DIIADDEPLT (Pep19), with slightly better inverse agonist activity at cannabinoid type 1 receptors. Pep19 induced uncoupling protein 1 expression in both white adipose tissue and 3T3-L1 differentiated adipocytes; in the latter, Pep19 activates pERK1/2 and AKT signaling pathways. Uncoupling protein 1 expression induced by Pep19 in 3T3-L1 differentiated adipocytes is blocked by AM251, a cannabinoid type 1 receptors antagonist. Oral administration of Pep19 into diet-induced obese Wistar rats significantly reduces adiposity index, whole body weight, glucose, triacylglycerol, cholesterol and blood pressure, without altering heart rate; changes in the number and size of adipocytes were also observed. Pep19 has no central nervous system effects as suggested by the lack of brain c-Fos expression, cell toxicity, induction of the cannabinoid tetrad, depressive- and anxiety-like behaviors. Therefore, Pep19 has several advantages over previously identified peripherally active cannabinoid compounds, and could have clinical applications.

  12. Peptide Phage Display as a Tool for Drug Discovery: Targeting Membrane Receptors

    Directory of Open Access Journals (Sweden)

    Tomaz Bratkovic

    2011-01-01

    Full Text Available Ligands selected from phage-displayed random peptide libraries tend to be directed to biologically relevant sites on the surface of the target protein. Consequently, peptides derived from library screenings often modulate the target protein’s activity in vitro and in vivo and can be used as lead compounds in drug design and as alternatives to antibodies for target validation in both genomics and drug discovery. This review discusses the use of phage display to identify membrane receptor modulators with agonistic or antagonistic activities. Because isolating or producing recombinant membrane proteins for use as target molecules in library screening is often impossible, innovative selection strategies such as panning against whole cells or tissues, recombinant receptor ectodomains, or neutralizing antibodies to endogenous binding partners were devised. Prominent examples from a two-decade history of peptide phage display will be presented, focusing on the design of affinity selection experiments, methods for improving the initial hits, and applications of the identified peptides.

  13. Development and use of engineered peptide deformylase in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia

    2012-01-01

    Deze thesis beschrijft het onderzoek naar potentieel van het gebruik van het peptide deformylase (PDF) in chemo enzymatische peptide synthese. PDF is geschikt voor selective N terminale deformylatie van bepaalde N-formyl-peptides zonder gelijktijdige hydrolyse van de peptide binding. Door de

  14. 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.

  15. STM studies of synthetic peptide monolayers

    Science.gov (United States)

    Bergeron, David J.; Clauss, Wilfried; Pilloud, Denis L.; Leslie Dutton, P.; Johnson, Alan T.

    1998-08-01

    We have used scanning probe microscopy to investigate self-assembled monolayers of chemically synthesized peptides. We find that the peptides form a dense uniform monolayer, above which is found a sparse additional layer. Using scanning tunneling microscopy, submolecular resolution can be obtained, revealing the alpha helices which constitute the peptide. The nature of the images is not significantly affected by the incorporation of redox cofactors (hemes) in the peptides.

  16. Antimicrobial activities of heparin-binding peptides.

    OpenAIRE

    Andersson, Emma; Rydengård, Victoria; Sonesson, Andreas; Mörgelin, Matthias; Björck, Lars; Schmidtchen, Artur

    2004-01-01

    Antimicrobial peptides are effector molecules of the innate immune system. We recently showed that the human antimicrobial peptides alpha-defensin and LL-37 bind to glycosaminoglycans (heparin and dermatan sulphate). Here we demonstrate the obverse, i.e. structural motifs associated with heparin affinity (cationicity, amphipaticity, and consensus regions) may confer antimicrobial properties to a given peptide. Thus, heparin-binding peptides derived from laminin isoforms, von Willebrand factor...

  17. Role of opioid peptides in the regulation of cytokine production by murine CD4+ T cells.

    Science.gov (United States)

    van den Bergh, P; Dobber, R; Ramlal, S; Rozing, J; Nagelkerken, L

    1994-03-01

    The presence of the opioid peptides alpha- and beta-endorphin (-End) but not methionine enkephalin (Met-enk) in in vitro cultures of purified CD4+ T cells, stimulated with concanavalin A in the presence of irradiated spleen cells, resulted in a threefold stimulation of IL-2, IL-4, and IFN-gamma production. The stimulating effect was dependent on the concentration of the peptides and reached optimal values in the dose range from 10(-12) to 10(-10) M. Similar results were obtained when purified CD4+ T cells were stimulated with immobilized anti-CD3, indicating a direct effect of opioid peptides on CD4+ T cells. Moreover, in this system a twofold enhancement of IL-6, but not IL-1, secretion was observed. These stimulatory effects were not mediated through opioid receptors since the peptide fragment beta-End6-31 that lacks the N-terminal opioid receptor binding part was still stimulatory. This is in agreement with our finding that beta-End did not affect cAMP, as described for the triggering of classical opioid receptors. Experiments undertaken to reveal the mechanism of action of opioid peptides suggest an overall enhancement of lymphokine production: (1) enhancement of IL-4 production occurred also in the presence of excess IL-2; and (2) neither IL-1 receptor-antagonizing protein nor anti-IL-6 were capable to abrogate the stimulatory effect on IL-2 and IL-4 production. Finally, the presence and activity of opioid receptors in cultures of CD4+ T cells were substantiated by the fact that the opioid receptor antagonist naloxone by itself enhanced cytokine synthesis, which points to the endogenous production by lymphocytes of down-regulating opioid peptides.

  18. One Hundred Years of Peptide Chemistry

    Indian Academy of Sciences (India)

    ber of residues are often denoted as peptides. The chemical synthesis of peptides, as envisaged by Fischer, involves ... known as genetically encoded as building blocks of peptides and proteins. Almost all of .... inhibit final stages of the enzymatic construction of the bacterial peptidoglycan cell wall component, a network of.

  19. Toxins and antimicrobial peptides: interactions with membranes

    Science.gov (United States)

    Schlamadinger, Diana E.; Gable, Jonathan E.; Kim, Judy E.

    2009-08-01

    The innate immunity to pathogenic invasion of organisms in the plant and animal kingdoms relies upon cationic antimicrobial peptides (AMPs) as the first line of defense. In addition to these natural peptide antibiotics, similar cationic peptides, such as the bee venom toxin melittin, act as nonspecific toxins. Molecular details of AMP and peptide toxin action are not known, but the universal function of these peptides to disrupt cell membranes of pathogenic bacteria (AMPs) or a diverse set of eukaryotes and prokaryotes (melittin) is widely accepted. Here, we have utilized spectroscopic techniques to elucidate peptide-membrane interactions of alpha-helical human and mouse AMPs of the cathelicidin family as well as the peptide toxin melittin. The activity of these natural peptides and their engineered analogs was studied on eukaryotic and prokaryotic membrane mimics consisting of <200-nm bilayer vesicles composed of anionic and neutral lipids as well as cholesterol. Vesicle disruption, or peptide potency, was monitored with a sensitive fluorescence leakage assay. Detailed molecular information on peptidemembrane interactions and peptide structure was further gained through vibrational spectroscopy combined with circular dichroism. Finally, steady-state fluorescence experiments yielded insight into the local environment of native or engineered tryptophan residues in melittin and human cathelicidin embedded in bilayer vesicles. Collectively, our results provide clues to the functional structures of the engineered and toxic peptides and may impact the design of synthetic antibiotic peptides that can be used against the growing number of antibiotic-resistant pathogens.

  20. Ribosome evolution: Emergence of peptide synthesis machinery

    Indian Academy of Sciences (India)

    allows the histidine to position close to the PTC during the reaction, it may contribute to improving peptide bond formation. Thus, it is important to analyse biomolecular interactions in terms of the dynamic nature of the structure. 3. Origin of peptide bond formation and the RNA world. Minihelix-based peptide bond formation ...

  1. Double-Stranded Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2001-01-01

    A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Synthetic Procedures for Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  3. Glucagon-like peptide-1

    DEFF Research Database (Denmark)

    Deacon, C F; Holst, Jens Juul; Carr, R D

    1999-01-01

    Type 2 diabetes mellitus is a metabolic disease resulting in raised blood sugar which, if not satisfactorily controlled, can cause severe and often debilitating complications. Unfortunately, for many patients, the existing therapies do not give adequate control. Glucagon-like peptide-1 (GLP-1...

  4. Peptide Receptor Radionuclide Therapy & Oncology

    NARCIS (Netherlands)

    H. Bergsma (Hendrik)

    2017-01-01

    markdownabstractNeuroendocrine tumors (NETs) are rare neoplasms with differences in clinical presentation, course and prognosis. Most of the NETs express the somatostatine receptor, which can be utilized for imaging and therapy. Radiolabeled somatostatin analogs can be used for peptide receptor

  5. Glucagon-like peptide-1

    DEFF Research Database (Denmark)

    Deacon, C F; Holst, Jens Juul; Carr, R D

    1999-01-01

    Type 2 diabetes mellitus is a metabolic disease resulting in raised blood sugar which, if not satisfactorily controlled, can cause severe and often debilitating complications. Unfortunately, for many patients, the existing therapies do not give adequate control. Glucagon-like peptide-1 (GLP-1...... advantages offered by GLP-1 and give the hope of providing effective glycemic control without the risk of overt hypoglycemia....

  6. Synthetic peptides for diagnostic use

    NARCIS (Netherlands)

    Meloen, R.H.; Langedijk, J.P.M.; Langeveld, J.P.M.

    1997-01-01

    Synthetic peptides representing relevant B-cell epitopes are, potentially, ideal antigens to be used in diagnostic assays because of their superior properties with respect to quality control as compared to those of biologically derived molecules and the much higher specificity that sometimes can be

  7. Next generation natriuretic peptide measurement

    DEFF Research Database (Denmark)

    Hunter, Ingrid; Goetze, Jens P

    2012-01-01

    in the molecular heterogeneity could in itself contain valuable information of clinical status, and the time seems right for industry and dedicated researchers in the field to get together and discuss the next generation natriuretic peptide measurement. In such an environment, new strategies can be developed...

  8. Atrial natriuretic peptides in plasma

    DEFF Research Database (Denmark)

    Goetze, Jens P; Holst Hansen, Lasse; Terzic, Dijana

    2015-01-01

    derivatizations. In this mini-review, we summarize measurement of the principal cardiac hormone, e.g. atrial natriuretic peptide (ANP) and its precursor fragments. We also highlight some of the analytical pitfalls and problems and the concurrent clinical "proof of concept". We conclude that biochemical research...

  9. Metabotropic glutamate receptor antagonists but not NMDA antagonists affect conditioned taste aversion acquisition in the parabrachial nucleus of rats

    Czech Academy of Sciences Publication Activity Database

    Valeš, Karel; Zach, P.; Bielavská, Edita

    2006-01-01

    Roč. 169, č. 1 (2006), s. 50-57 ISSN 0014-4819 R&D Projects: GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z5011922 Keywords : learning * microdialysis * glutamate antagonists Subject RIV: FH - Neurology Impact factor: 1.959, year: 2006

  10. Conformation of cyclo-(Gln-Trp-Phe-{beta}Ala-Leu-Met), a NK-2 tachykinin receptor antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jong Myung [Silla Univ., Pusan (Korea, Republic of)

    1999-10-01

    Solution conformation of cyclo-(Gln-Trp-Phe-{beta}Ala-Leu-Met), new NK-2 antagonist in dimethyl sulfoxide solution, has been determined by the use of two-dimensional nuclear magnetic resonance spectroscopy combined with simulated annealing calculations. The peptide exhibited converged structures with the atomic root-mean-square difference for the backbone atoms (N, C{sup a}, C') of all residues being 0.02A in the 25 annealed structures. The analysis of the structures indicated that the cyclic peptide has three intramolecular hydrogen bonds between Met NH and {beta}Ala CO, {beta}Ala NH and Met CO, Phe NH and Met CO, and contain a type-I {beta}-turn with Gln and Trp and a {gamma}-turn with Leu. The addition of an extra methylene group to Gly, i.e. {beta}-Ala residue, may relax some unfavorable restraints in the cyclic backbone structure, hence enabling an additional hydrogen bond, which results in stabilizing one conformation.

  11. DIHYDROPYRIDINE CALCIUM ANTAGONISTS: DATA OF EVIDENCE BASED MEDICINE AND RECOM-MENDATIONS ON PRACTICAL USE

    Directory of Open Access Journals (Sweden)

    S. Y. Martsevich

    2007-01-01

    Full Text Available The classification of calcium antagonists is presented. There were considered the results of large randomized trials, which were devoted to study of influence of dihydropyridine calcium antagonists on the risk of cardiovascular complications. The place of dihydropyridine calcium antagonists in modern recommendations on treatment of arterial hypertension and ischemic heart disease is defined. The clinical importance of differences between various presentations of dihy-dropyridine calcium antagonists is stressed.

  12. DIHYDROPYRIDINE CALCIUM ANTAGONISTS: DATA OF EVIDENCE BASED MEDICINE AND RECOM-MENDATIONS ON PRACTICAL USE

    Directory of Open Access Journals (Sweden)

    S. Y. Martsevich

    2015-12-01

    Full Text Available The classification of calcium antagonists is presented. There were considered the results of large randomized trials, which were devoted to study of influence of dihydropyridine calcium antagonists on the risk of cardiovascular complications. The place of dihydropyridine calcium antagonists in modern recommendations on treatment of arterial hypertension and ischemic heart disease is defined. The clinical importance of differences between various presentations of dihy-dropyridine calcium antagonists is stressed.

  13. 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.

  14. Preparation of polypeptides comprising multiple TAA peptides.

    Science.gov (United States)

    Ni, Bing; Jia, Zhengcai; Wu, Yuzhang

    2014-01-01

    Polypeptides consisting of multiple tumor-associated antigen epitopes (multiepitope peptides) are commonly used as therapeutic peptide cancer vaccines in experimental studies and clinical trials. These methods include polypeptides composed of multiple major histocompatibility complex (MHC) class I-restricted cytotoxic T cell (CTL) epitopes and those containing multiple CTL epitopes and one T helper (Th) epitope. This chapter describes a complete set of methods for preparing multiepitope peptides and branched multiple antigen peptides (MAPs), including sequence design, peptide synthesis, purification, preservation, and the preparation of polypeptide solutions.

  15. A Novel Nociceptin Receptor Antagonist LY2940094 Inhibits Excessive Feeding Behavior in Rodents: A Possible Mechanism for the Treatment of Binge Eating Disorder.

    Science.gov (United States)

    Statnick, Michael A; Chen, Yanyun; Ansonoff, Michael; Witkin, Jeffrey M; Rorick-Kehn, Linda; Suter, Todd M; Song, Min; Hu, Charlie; Lafuente, Celia; Jiménez, Alma; Benito, Ana; Diaz, Nuria; Martínez-Grau, Maria Angeles; Toledo, Miguel A; Pintar, John E

    2016-02-01

    Nociceptin/orphanin FQ (N/OFQ), a 17 amino acid peptide, is the endogenous ligand of the ORL1/nociceptin-opioid-peptide (NOP) receptor. N/OFQ appears to regulate a variety of physiologic functions including stimulating feeding behavior. Recently, a new class of thienospiro-piperidine-based NOP antagonists was described. One of these molecules, LY2940094 has been identified as a potent and selective NOP antagonist that exhibited activity in the central nervous system. Herein, we examined the effects of LY2940094 on feeding in a variety of behavioral models. Fasting-induced feeding was inhibited by LY2940094 in mice, an effect that was absent in NOP receptor knockout mice. Moreover, NOP receptor knockout mice exhibited a baseline phenotype of reduced fasting-induced feeding, relative to wild-type littermate controls. In lean rats, LY2940094 inhibited the overconsumption of a palatable high-energy diet, reducing caloric intake to control chow levels. In dietary-induced obese rats, LY2940094 inhibited feeding and body weight regain induced by a 30% daily caloric restriction. Last, in dietary-induced obese mice, LY2940094 decreased 24-hour intake of a high-energy diet made freely available. These are the first data demonstrating that a systemically administered NOP receptor antagonist can reduce feeding behavior and body weight in rodents. Moreover, the hypophagic effect of LY2940094 is NOP receptor dependent and not due to off-target or aversive effects. Thus, LY2940094 may be useful in treating disorders of appetitive behavior such as binge eating disorder, food choice, and overeating, which lead to obesity and its associated medical complications and morbidity. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  16. Opioid antagonists with minimal sedation for opioid withdrawal.

    Science.gov (United States)

    Gowing, Linda; Ali, Robert; White, Jason M

    2017-05-29

    Managed withdrawal is a necessary step prior to drug-free treatment or as the endpoint of long-term substitution treatment. To assess the effects of opioid antagonists plus minimal sedation for opioid withdrawal. Comparators were placebo as well as more established approaches to detoxification, such as tapered doses of methadone, adrenergic agonists, buprenorphine and symptomatic medications. We updated our searches of the following databases to December 2016: CENTRAL, MEDLINE, Embase, PsycINFO and Web of Science. We also searched two trials registers and checked the reference lists of included studies for further references to relevant studies. We included randomised and quasi-randomised controlled clinical trials along with prospective controlled cohort studies comparing opioid antagonists plus minimal sedation versus other approaches or different opioid antagonist regimens for withdrawal in opioid-dependent participants. We used standard methodological procedures expected by Cochrane. Ten studies (6 randomised controlled trials and 4 prospective cohort studies, involving 955 participants) met the inclusion criteria for the review. We considered 7 of the 10 studies to be at high risk of bias in at least one of the domains we assessed.Nine studies compared an opioid antagonist-adrenergic agonist combination versus a treatment regimen based primarily on an alpha 2 -adrenergic agonist (clonidine or lofexidine). Other comparisons (placebo, tapered doses of methadone, buprenorphine) made by included studies were too diverse for any meaningful analysis. This review therefore focuses on the nine studies comparing an opioid antagonist (naltrexone or naloxone) plus clonidine or lofexidine versus treatment primarily based on clonidine or lofexidine.Five studies took place in an inpatient setting, two studies were in outpatients with day care, two used day care only for the first day of opioid antagonist administration, and one study described the setting as outpatient

  17. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

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

    2010-01-01

    An increasing number of reported cases of drug resistant Staphylococcus aureus and Pseudomonas aeruginosa, demonstrate the urgent need for new therapeutics that are effective against such and other multi-drug resistant bacteria. Antimicrobial peptides have for two decades now been looked upon...... as interesting leads for development of new therapeutics combating these drug resistant microbes. High-throughput screening of peptide libraries have generated large amounts of information on peptide activities. However, scientists still struggle with explaining the specific peptide motifs resulting...... 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...

  18. Natural and synthetic peptides with antifungal activity.

    Science.gov (United States)

    Ciociola, Tecla; Giovati, Laura; Conti, Stefania; Magliani, Walter; Santinoli, Claudia; Polonelli, Luciano

    2016-08-01

    In recent years, the increase of invasive fungal infections and the emergence of antifungal resistance stressed the need for new antifungal drugs. Peptides have shown to be good candidates for the development of alternative antimicrobial agents through high-throughput screening, and subsequent optimization according to a rational approach. This review presents a brief overview on antifungal natural peptides of different sources (animals, plants, micro-organisms), peptide fragments derived by proteolytic cleavage of precursor physiological proteins (cryptides), synthetic unnatural peptides and peptide derivatives. Antifungal peptides are schematically reported based on their structure, antifungal spectrum and reported effects. Natural or synthetic peptides and their modified derivatives may represent the basis for new compounds active against fungal infections.

  19. Effects of histamine and its antagonists on murine T-cells and bone marrow-derived dendritic cells

    Directory of Open Access Journals (Sweden)

    Hu XF

    2015-08-01

    Full Text Available Xiufen Hu,1,* Mohammad Ishraq Zafar,2,* Feng Gao2 1Department of Paediatrics, Tongji Hospital, 2Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: We determined the effects of histamine and its antagonists on the surface marker expression of dendritic cells (DCs and the influence of lipopolysaccharide (LPS, histamine, and histamine receptor antagonists on DCs and T-cells. The bone marrow was extracted from the femurs and tibiae of 6- to 8-week-old female Balb/c mice and cultured in medium containing penicillin, streptomycin, L-glutamine, fetal calf serum, or granulocyte macrophage colony-stimulating factor (GM-CSF alone or with interleukin (IL-4. The cells received three different doses of LPS and histamine, plus three different doses of descarboethoxyloratadine (DCL. We assayed the supernatant for various cytokines. The spleen cells of DO11.10 mice were examined by flow cytometry, which included labeling and sorting CD4+ T-cells, as well as coculture of DCs and T-cells with ovalbumin (OVA323–339 peptide. Histamine or histamine plus DCL did not affect the expression of major histocompatibility complex class II, CD11c, CD11b, CD86, and CD80. However, GM-CSF increased the expression of all markers except CD80. Histamine increased interferon-γ production in GM-CSF + IL-4-cultured cells; it also enhanced IL-10 production, but suppressed IL-12 production in LPS-stimulated DCs with no DCL. Cimetidine inhibited IL-10 production and restored IL-12 secretion in LPS-treated DCs. LPS increased IL-10 and decreased IL-12 levels. GM-CSF + IL-4-generated DCs had a stronger stimulatory effect on DO11.10 T-cell proliferation than GM-CSF-generated DCs. Inducible costimulator ligand expression was higher in GM-CSF + IL-4- than in GM-CSF-generated DC groups after 2 days of coculture, but decreased 4 days

  20. Design of peptide-targeted liposomes containing nucleic acids.

    Science.gov (United States)

    Santos, Adriana O; da Silva, Lígia C Gomes; Bimbo, Luís M; de Lima, Maria C Pedroso; Simões, Sérgio; Moreira, João N

    2010-03-01

    Anticancer systemic gene silencing therapy has been so far limited by the inexistence of adequate carrier systems that ultimately provide an efficient intracellular delivery into target tumor cells. In this respect, one promising strategy involves the covalent attachment of internalizing-targeting ligands at the extremity of PEG chains grafted onto liposomes. Therefore, the present work aims at designing targeted liposomes containing nucleic acids, with small size, high encapsulation efficiency and able to be actively internalized by SCLC cells, using a hexapeptide (antagonist G) as a targeting ligand. For this purpose, the effect of the liposomal preparation method, loading material (ODN versus siRNA) and peptide-coupling procedure (direct coupling versus post-insertion) on each of the above-mentioned parameters was assessed. Post-insertion of DSPE-PEG-antagonist G conjugates into preformed liposomes herein named as stabilized lipid particles, resulted in targeted vesicles with a mean size of about 130 nm, encapsulation efficiency close to 100%, and a loading capacity of approximately 5 nmol siRNA/mumol of total lipid. In addition, the developed targeted vesicles showed increased internalization in SCLC cells, as well as in other tumor cells and HMEC-1 microvascular endothelial cells. The improved cellular association, however, did not correlate with enhanced downregulation of the target protein (Bcl-2) in SCLC cells. These results indicate that additional improvements need to be performed in the future, namely by ameliorating the access of the nucleic acids to the cytoplasm of the tumor cells following receptor-mediated endocytosis. Copyright 2009 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Graham M West

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

  2. Tactical Approaches to Interconverting GPCR Agonists and Antagonists.

    Science.gov (United States)

    Dosa, Peter I; Amin, Elizabeth Ambrose

    2016-02-11

    There are many reported examples of small structural modifications to GPCR-targeted ligands leading to major changes in their functional activity, converting agonists into antagonists or vice versa. These shifts in functional activity are often accompanied by negligible changes in binding affinity. The current perspective focuses on outlining and analyzing various approaches that have been used to interconvert GPCR agonists, partial agonists, and antagonists in order to achieve the intended functional activity at a GPCR of therapeutic interest. An improved understanding of specific structural modifications that are likely to alter the functional activity of a GPCR ligand may be of use to researchers designing GPCR-targeted drugs and/or probe compounds, specifically in cases where a particular ligand exhibits good potency but not the preferred functional activity at the GPCR of choice.

  3. Are peripheral opioid antagonists the solution to opioid side effects?

    LENUS (Irish Health Repository)

    Bates, John J

    2012-02-03

    Opioid medication is the mainstay of therapy for severe acute and chronic pain. Unfortunately, the side effects of these medications can affect patient comfort and safety, thus limiting their proven therapeutic potential. Whereas the main analgesic effects of opioids are centrally mediated, many of the common side effects are mediated via peripheral receptors. Novel peripheral opioid antagonists have been recently introduced that can block the peripheral actions of opioids without affecting centrally mediated analgesia. We review the clinical and experimental evidence of their efficacy in ameliorating opioid side effects and consider what further information might be useful in defining their role. IMPLICATIONS: The major analgesic effects of opioid medication are mediated within the brain and spinal cord. Many of the side effects of opioids are caused by activation of receptors outside these areas. Recently developed peripherally restricted opioid antagonists have the ability to block many opioid side effects without affecting analgesia.

  4. In-silico guided discovery of novel CCR9 antagonists

    Science.gov (United States)

    Zhang, Xin; Cross, Jason B.; Romero, Jan; Heifetz, Alexander; Humphries, Eric; Hall, Katie; Wu, Yuchuan; Stucka, Sabrina; Zhang, Jing; Chandonnet, Haoqun; Lippa, Blaise; Ryan, M. Dominic; Baber, J. Christian

    2018-03-01

    Antagonism of CCR9 is a promising mechanism for treatment of inflammatory bowel disease, including ulcerative colitis and Crohn's disease. There is limited experimental data on CCR9 and its ligands, complicating efforts to identify new small molecule antagonists. We present here results of a successful virtual screening and rational hit-to-lead campaign that led to the discovery and initial optimization of novel CCR9 antagonists. This work uses a novel data fusion strategy to integrate the output of multiple computational tools, such as 2D similarity search, shape similarity, pharmacophore searching, and molecular docking, as well as the identification and incorporation of privileged chemokine fragments. The application of various ranking strategies, which combined consensus and parallel selection methods to achieve a balance of enrichment and novelty, resulted in 198 virtual screening hits in total, with an overall hit rate of 18%. Several hits were developed into early leads through targeted synthesis and purchase of analogs.

  5. Interleukin-1-receptor antagonist in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Larsen, Claus M; Faulenbach, Mirjam; Vaag, Allan

    2007-01-01

    BACKGROUND: The expression of interleukin-1-receptor antagonist is reduced in pancreatic islets of patients with type 2 diabetes mellitus, and high glucose concentrations induce the production of interleukin-1beta in human pancreatic beta cells, leading to impaired insulin secretion, decreased cell...... proliferation, and apoptosis. METHODS: In this double-blind, parallel-group trial involving 70 patients with type 2 diabetes, we randomly assigned 34 patients to receive 100 mg of anakinra (a recombinant human interleukin-1-receptor antagonist) subcutaneously once daily for 13 weeks and 36 patients to receive......, and the body-mass index were similar in the two study groups. Symptomatic hypoglycemia was not observed, and there were no apparent drug-related serious adverse events. CONCLUSIONS: The blockade of interleukin-1 with anakinra improved glycemia and beta-cell secretory function and reduced markers of systemic...

  6. Non-imidazole histamine NO-donor H3-antagonists.

    Science.gov (United States)

    Tosco, Paolo; Bertinaria, Massimo; Di Stilo, Antonella; Cena, Clara; Fruttero, Roberta; Gasco, Alberto

    2005-01-01

    Recently a series of H3-antagonists related to Imoproxifan was realised (I); in these products the oxime substructure of the lead was constrained in NO-donor furoxan systems and in the corresponding furazan derivatives. In this paper, a new series of compounds derived from I by substituting the imidazole ring with the ethoxycarbonylpiperazino moiety present in the non-imidazole H3-ligand A-923 is described. For all the products synthesis and preliminary pharmacological characterisation, as well as their hydrophilic-lipophilic balance, are reported. The imidazole ring replacement generally results in a decreased H3-antagonist activity with respect to the analogues of series I and, in some cases, induces relaxing effects on the electrically contracted guinea-pig ileum, probably due to increased affinity for other receptor systems.

  7. Potential Clinical Implications of the Urotensin II Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Emilie Kane

    2011-07-01

    Full Text Available Urotensin-II (UII, which binds to its receptor UT, plays an important role in the heart, kidneys, pancreas, adrenal gland and CNS. In the vasculature, it acts as a potent endothelium-independent vasoconstrictor and endothelium-dependent vasodilator. In disease states, this constriction-dilation equilibrium is disrupted. There is an upregulation of the UII system in heart disease, metabolic syndrome and kidney failure. The increase in UII release and UT expression suggest that UII system may be implicated in the pathology and pathogenesis of these diseases by causing an increase in ACAT-1 activity leading to SMC proliferation and foam cell infiltration, insulin resistance (DMII, as well as inflammation, high blood pressure and plaque formation. Recently, UT antagonists such as SB-611812, palosuran, and most recently a piperazino-isoindolinone based antagonist have been developed in the hope of better understanding the UII system and treating its associated diseases.

  8. Molecular mechanism of action of monocyclam versus bicyclam non-peptide antagonists in the CXCR4 chemokine receptor

    DEFF Research Database (Denmark)

    Rosenkilde, Mette M; Gerlach, Lars-Ole; Hatse, Sigrid

    2007-01-01

    in transmembrane (TM)-VI (AspVI:23/Asp(262)) and TM-VII (GluVII:06/Glu(288)). Importantly, AMD3465 has picked up novel interaction sites, for example, His(281) located at the interface of extracellular loop 3 and TM-VII and HisIII:05 (His(113)) in the middle of the binding pocket. It is concluded that the simple N......-pyridinylmethylene moiety of AMD3465 substitutes for one of the complex cyclam moieties of AMD3100 through an improved and in fact expanded interaction pattern mainly with residues located in the extracellular segments of TM-VI and -VII of the CXCR4 receptor. It is suggested that the remaining cyclam ring of AMD3465, which...

  9. A novel antibacterial peptide active against peach crown gall (Agrobacterium tumefaciens) isolated from cyanide-tolerant actinomycetes G19.

    Science.gov (United States)

    Wang, Shufang; Ji, Jinglin; Ma, Huanpu; Liu, Zhimin

    2015-01-01

    An antimicrobial peptide was extracted from the antagonistic actinomycetes G19. It was designated as G19-F. By using MALDI-TOF mass spectrometry, the molecular weight of G19-F was determined. The primary structure of the antimicrobial peptide was determined using N-terminal sequencing and mass spectrometry. Results showed that the peptide had eleven amino acids, with the sequence D-V-C-D-G-G-D-G-D-E-D, and a calculated molecular mass of 1,096 Da. G19-F showed antimicrobial activity against peach crown gall caused by Agrobacterium tumefaciens. The antimicrobial peptide maintained its activity after being heated to 100 °C and exhibited stability from pH 4 to 10. Its activity has also remained after ultraviolet irradiation. The mechanism by which G19-F inhibits A. tumefaciens was to increase permeability of the cell membrane and destroy the cell wall structure. Furthermore, as a novel peptide, it has a potential for cure A. tumefaciens infection.

  10. Degradation and antioxidant activities of peptides and zinc-peptide complexes during in vitro gastrointestinal digestion.

    Science.gov (United States)

    Wang, Chan; Li, Bo; Wang, Bo; Xie, Ningning

    2015-04-15

    The degradation characteristics of three peptides (Ser-Met, Asn-Cys-Ser, and glutathione) and their zinc-peptide complexes were studied using a two-stage in vitro digestion model. Enzyme-resistant peptides and zinc-peptide complexes, antioxidant activities, and free amino acids released by digestive enzymes, were measured in this study. The results revealed that the three peptides and their zinc-peptide complexes were resistant to pepsin but not to pancreatin. Pancreatin can partly hydrolyse both peptides and zinc-peptide complexes, but more than half of them remaining in their original form after gastrointestinal digestion. The coordination of zinc improved the enzymatic resistance of the peptide due to lower solubility of complexes and affected the hydrolytic site of pepsin and pancreatin. Zinc-Asn-Cys-Ser, which is highly resistant to enzymatic hydrolysis and maintains Zn in a soluble form, may have potential to improve Zn bioavailability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Analysis of peptide uptake and location of root hair-promoting peptide accumulation in plant roots.

    Science.gov (United States)

    Matsumiya, Yoshiki; Taniguchi, Rikiya; Kubo, Motoki

    2012-03-01

    Peptide uptake by plant roots from degraded soybean-meal products was analyzed in Brassica rapa and Solanum lycopersicum. B. rapa absorbed about 40% of the initial water volume, whereas peptide concentration was decreased by 75% after 24 h. Analysis by reversed-phase HPLC showed that number of peptides was absorbed by the roots during soaking in degraded soybean-meal products for 24 h. Carboxyfluorescein-labeled root hair-promoting peptide was synthesized, and its localization, movement, and accumulation in roots were investigated. The peptide appeared to be absorbed by root hairs and then moved to trichoblasts. Furthermore, the peptide was moved from trichoblasts to atrichoblasts after 24 h. The peptide was accumulated in epidermal cells, suggesting that the peptide may have a function in both trichoblasts and atrichoblasts. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

  12. Anorexia induction by the trichothecene deoxynivalenol (vomitoxin) is mediated by the release of the gut satiety hormone peptide YY.

    Science.gov (United States)

    Flannery, Brenna M; Clark, Erica S; Pestka, James J

    2012-12-01

    Consumption of deoxynivalenol (DON), a trichothecene mycotoxin known to commonly contaminate grain-based foods, suppresses growth of experimental animals, thus raising concerns over its potential to adversely affect young children. Although this growth impairment is believed to result from anorexia, the initiating mechanisms for appetite suppression remain unknown. Here, we tested the hypothesis that DON induces the release of satiety hormones and that this response corresponds to the toxin's anorectic action. Acute ip exposure to DON had no effect on plasma glucagon-like peptide-1, leptin, amylin, pancreatic polypeptide, gastric inhibitory peptide, or ghrelin; however, the toxin was found to robustly elevate peptide YY (PYY) and cholecystokinin (CCK). Specifically, ip exposure to DON at 1 and 5mg/kg bw induced PYY by up to 2.5-fold and CCK by up to 4.1-fold. These responses peaked within 15-120 min and lasted up to 120 min (CCK) and 240 min (PPY), corresponding with depressed rates of food intake. Direct administration of exogenous PYY or CCK similarly caused reduced food intake. Food intake experiments using the NPY2 receptor antagonist BIIE0246 and the CCK1A receptor antagonist devazepide, individually, suggested that PYY mediated DON-induced anorexia but CCK did not. Orolingual exposure to DON induced plasma PYY and CCK elevation and anorexia comparable with that observed for ip exposure. Taken together, these findings suggest that PYY might be one critical mediator of DON-induced anorexia and, ultimately, growth suppression.

  13. State Estimation For An Agonistic-Antagonistic Muscle System

    OpenAIRE

    Nguyen, Thang; Warner, Holly; La, Hung; Mohammadi, Hanieh; Simon, Dan; Richter, Hanz

    2017-01-01

    Research on assistive technology, rehabilitation, and prosthesis requires the understanding of human machine interaction, in which human muscular properties play a pivotal role. This paper studies a nonlinear agonistic-antagonistic muscle system based on the Hill muscle model. To investigate the characteristics of the muscle model, the problem of estimating the state variables and activation signals of the dual muscle system is considered. In this work, parameter uncertainty and unknown input...

  14. Histamine-2 receptor antagonists as immunomodulators: new therapeutic views?

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen

    1996-01-01

    Considerable evidence has emerged to suggest that histamine participates in the regulation of the inflammatory response, immune reaction, coagulation cascade, and cardiovascular function. Furthermore, histamine may play a major role in the growth of normal and malignant tissue as a regulator...... antagonists as adjuvant single drugs to reduce trauma-, blood transfusion- and sepsis-induced immunosuppression has led to research in combined treatment regimens in major surgery, particularly, of patients operated on for malignant diseases....

  15. Chitinolytic Enterobacter agglomerans Antagonistic to Fungal Plant Pathogens

    OpenAIRE

    Chernin, L.; Ismailov, Z.; Haran, S.; Chet, I.

    1995-01-01

    Three Enterobacter agglomerans strains which produce and excrete proteins with chitinolytic activity were found while screening soil-borne bacteria antagonistic to fungal plant pathogens. The chitinolytic activity was induced when the strains were grown in the presence of colloidal chitin as the sole carbon source. It was quantitated by using assays with chromogenic p-nitrophenyl analogs of disaccharide, trisaccharide, and tetrasaccharide derivatives of N-acetylglucosamine. A set of three flu...

  16. ANTIHYPERTENSIVE TREATMENT IN ELDERLY PATIENTS WITH DIHYDROPYRIDINE CALCIUM ANTAGONISTS

    OpenAIRE

    Y. A. Karpov; V. V. Buza

    2006-01-01

    The proofs of necessity of active arterial hypertension (AH) treatment in elderly patients are given. Peculiarities of pathogenesis of AH in elderly patients, connected predominantly with loss of big arteries elasticity and reasoning widely spread of isolated systolic AH in these patients, are discussed. Advantages of dihydropyridine calcium antagonists (DPCA) for AH treatment in elderly patients are proved, safety of treatment with DPCA is discussed. Data of clinical studies is analyzed. Ana...

  17. Renoprotective effects of calcium antagonists on kidney disease

    OpenAIRE

    Mochammad Sja'bani, Mochammad Sja'bani

    2015-01-01

    There has been a growing number of evidence that calcium antagonists provide a salutary effects in preserving kidneys against acute renal ischemia in patients at increasing risk. Their beneficial effects on cellular and mitochondrial calcium may explain the effects on renal hemodynamics and metabolics. It seems, that they do not directly vasodilate kidney vessels but alter the response towards vasoconstrictor agents. This effect may mediate diuretic and natriuretic effect of calcium antagonis...

  18. Deoxycholic acid conjugates are muscarinic cholinergic receptor antagonists.

    Science.gov (United States)

    Raufman, Jean-Pierre; Chen, Ying; Zimniak, Piotr; Cheng, Kunrong

    2002-08-01

    In the course of examining the actions of major human bile acids on cholinergic receptors, we discovered that conjugates of lithocholic acid are partial muscarinic agonists. In the present communication, we report that conjugates of deoxycholic acid (DC) act as cholinergic muscarinic receptor antagonists. Chinese hamster ovary (CHO) cells expressing rat M3-muscarinic receptors were used to test bile acids for inhibition of radioligand [N- (3)H-methylscopolamine ((3)H-NMS)] binding; alteration of inositol phosphate (IP) formation; mitogen-activated protein (MAP) kinase phosphorylation and cell toxicity. We observed approximately 18.8, 30.3 and 37.1% inhibition of (3)H-NMS binding with DC and its glycine (DCG) and taurine (DCT) conjugates, respectively (all 100 micromol/l, p exclusion or lactate dehydrogenase release from CHO-M3 cells. We observed the following rank order of potency (IC(50) micromol/l) for inhibition of (3)H-NMS by muscarinic antagonists and bile acids: NMS (0.0004) > 4-DAMP (0.009) > atropine (0.012) > DCT (170) > DCG (250). None of the bile acids tested were hydrolyzed by recombinant cholinesterase. At concentrations achieved in human bile, DC derivatives are natural muscarinic antagonists. Copyright 2002 S. Karger AG, Basel

  19. Glutamate receptor antagonists with the potential for migraine treatment.

    Science.gov (United States)

    Ferrari, Anna; Rustichelli, Cecilia; Baraldi, Carlo

    2017-12-01

    Preclinical, clinical, and other (e.g., genetic) evidence support the concept that migraine susceptibility may at least partially result from a glutamatergic system disorder. Therefore, the receptors of the glutamatergic system are considered relatively new targets for investigational drugs to treat migraine. Investigational and established glutamate receptor antagonists (GluRAs) have been shown to possess antinociceptive properties in preclinical models of trigeminovascular nociception and have been evaluated in clinical trials. This review focuses on preclinical and clinical studies of GluRAs for the treatment of migraine. Areas covered: A PubMed database search (from 1987 to December 2016) and a review of published studies on GluRAs in migraine were conducted. Expert opinion: All published clinical trials of investigational GluRAs have been unsuccessful in establishing benefit for acute migraine treatment. Clinical trial results contrast with the preclinical data, suggesting that glutamate (Glu) does not play a decisive role after the attack has already been triggered. These antagonists may instead be useful for migraine prophylaxis. Improving patient care requires further investigating and critically analyzing the role of Glu in migraine, designing experimental models to study more receptors and their corresponding antagonists, and identifying biomarkers to facilitate trials designed to target specific subgroups of migraine patients.

  20. Non-genetic inheritance and the patterns of antagonistic coevolution

    Directory of Open Access Journals (Sweden)

    Mostowy Rafal

    2012-06-01

    Full Text Available Abstract Background Antagonistic species interactions can lead to coevolutionary genotype or phenotype frequency oscillations, with important implications for ecological and evolutionary processes. However, direct empirical evidence of such oscillations is rare. The rarity of observations is generally attributed to inherent difficulties of ecological and evolutionary long-term studies, to weak or absent interaction between species, or to the absence of negative frequency-dependence. Results Here, we show that another factor – non-genetic inheritance, mediated for example by epigenetic mechanisms – can completely eliminate oscillations in the presence of such negative frequency dependence, even if only a small fraction of offspring are affected. We analytically derive the threshold value of this fraction at which the dynamics change from oscillatory to stable, and investigate how selection, mutation and generation times differences between the two species affect the threshold value. These results strongly suggest that the lack of phenotype frequency oscillations should not be attributed to the lack of strong interactions between antagonistic species. Conclusions Given increasing evidence of non-genetic effects on the outcomes of antagonistic species interactions, we suggest that these effects should be incorporated into ecological and evolutionary models of interacting species.

  1. Histamine H1 antagonists and clinical characteristics of febrile seizures

    Directory of Open Access Journals (Sweden)

    Zolaly MA

    2012-03-01

    Full Text Available Mohammed A ZolalyDepartment of Pediatrics, College of Medicine, Taibah University, Al-Madinah Al-Munawarah, Kingdom of Saudi ArabiaBackground: The purpose of this study was to determine whether seizure susceptibility due to antihistamines is provoked in patients with febrile seizures.Methods: The current descriptive study was carried out from April 2009 to February 2011 in 250 infants and children who visited the Madinah Maternity and Children's Hospital as a result of febrile convulsions. They were divided into two groups according to administration of antihistamines at the onset of fever.Results: Detailed clinical manifestations were compared between patients with and without administration of antihistamines. The time from fever detection to seizure onset was significantly shorter in the antihistamine group than that in the nonantihistamine group, and the duration of seizures was significantly longer in the antihistamine group than in the nonantihistamine group. No significant difference was found in time from fever detection to seizure onset or seizure duration between patients who received a first-generation antihistamine and those who received a second-generation antihistamine.Conclusion: Due to their central nervous system effects, H1 antagonists should not be administered to patients with febrile seizures and epilepsy. Caution should be exercised regarding the use of histamine H1 antagonists in young infants, because these drugs could potentially disturb the anticonvulsive central histaminergic system.Keywords: antihistamine, nonantihistamine, histamine H1 antagonist, febrile seizures

  2. Twisted gastrulation, a BMP antagonist, exacerbates podocyte injury.

    Directory of Open Access Journals (Sweden)

    Sachiko Yamada

    Full Text Available Podocyte injury is the first step in the progression of glomerulosclerosis. Previous studies have demonstrated the beneficial effect of bone morphogenetic protein 7 (Bmp7 in podocyte injury and the existence of native Bmp signaling in podocytes. Local activity of Bmp7 is controlled by cell-type specific Bmp antagonists, which inhibit the binding of Bmp7 to its receptors. Here we show that the product of Twisted gastrulation (Twsg1, a Bmp antagonist, is the central negative regulator of Bmp function in podocytes and that Twsg1 null mice are resistant to podocyte injury. Twsg1 was the most abundant Bmp antagonist in murine cultured podocytes. The administration of Bmp induced podocyte differentiation through Smad signaling, whereas the simultaneous administration of Twsg1 antagonized the effect. The administration of Bmp also inhibited podocyte proliferation, whereas simultaneous administration of Twsg1 antagonized the effect. Twsg1 was expressed in the glomerular parietal cells (PECs and distal nephron of the healthy kidney, and additionally in damaged glomerular cells in a murine model of podocyte injury. Twsg1 null mice exhibited milder hypoalbuminemia and hyperlipidemia, and milder histological changes while maintaining the expression of podocyte markers during podocyte injury model. Taken together, our results show that Twsg1 plays a critical role in the modulation of protective action of Bmp7 on podocytes, and that inhibition of Twsg1 is a promising means of development of novel treatment for podocyte injury.

  3. [Necrotic leg ulcer revealing vasculitis induced by vitamin K antagonists].

    Science.gov (United States)

    Chabli, H; Hocar, O; Akhdari, N; Amal, S; Hakkou, M; Hamdaoui, A

    2015-12-01

    Vitamin K antagonists are widely used in thromboembolic diseases. Hemorrhagic complications related to drug overdose represent their main side effect. We report a rare side effect, a severe and unexpected type of skin vasculitis - necrotic leg ulcer - induced by vitamin K antagonist. A 63-year-old female with a history of diabetes developed hyperalgesic necrotic ulcerations on the lower limbs one month after starting an acenocoumarol-based treatment for ischemic heart disease. Histological examination revealed lymphocytic vasculitis with fibrinoid necrosis. Etiological explorations searching for vasculitis were negative. In the absence of a precise etiology, drug-induced ulcer was suspected. Low molecular weight heparin was prescribed to replace acenocoumarol. The lesions slowly resolved with topical treatment. The chronological criteria and the negativity of etiological explorations allowed the diagnosis of vitamin K antagonist-induced necrotic skin ulcer. Clinicians should be aware of this rare complication induced by oral anticoagulants because of its practical therapeutic implications. This is the first case of necrotic leg ulcer induced by acenocoumarol corresponding histologically to necrotising lymphocytic vasculitis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Correlated EMG Oscillations between Antagonists during Cocontraction in Men.

    Science.gov (United States)

    Yoshitake, Yasuhide; Kanehisa, Hiroaki; Shinohara, Minoru

    2017-03-01

    The purpose of this study was to determine the modulation of common low-frequency oscillations in pools of motor units across antagonistic muscles because of the difference in the activation level of pools of spinal motor neurons and the presence of neuromuscular fatigue during intended cocontraction. Ten healthy young men (21.8 ± 1.5 yr) performed intended steady cocontractions of elbow flexors and extensors at maximal and a submaximal (10% of maximal EMG) effort. The submaximal cocontraction was repeated after sustained maximal contraction of elbow flexors. Surface EMG was recorded from the biceps brachii and triceps brachii muscles. Correlated EMG oscillations between the antagonistic muscles were quantified by the cross-correlation function (CCF) using rectified EMG for the EMG for the 3- to 15-Hz bands. The positive CCF peak in rectified EMG EMG, a negative CCF peak (i.e., out-of-phase oscillations) during submaximal cocontraction was smaller compared with maximal cocontraction but increased after the sustained contraction. Across subjects, the degree of reduction in maximal EMG amplitude after the sustained contraction was correlated with the amount of change in the CCF peak in EMG oscillations between antagonistic muscles occur during intended cocontraction, and 2) the magnitude of these correlated oscillations increases with the activation level of pools of spinal motor neurons and neuromuscular fatigue.

  5. Frequent epigenetic inactivation of Wnt antagonist genes in breast cancer

    Science.gov (United States)

    Suzuki, H; Toyota, M; Caraway, H; Gabrielson, E; Ohmura, T; Fujikane, T; Nishikawa, N; Sogabe, Y; Nojima, M; Sonoda, T; Mori, M; Hirata, K; Imai, K; Shinomura, Y; Baylin, S B; Tokino, T

    2008-01-01

    Although mutation of APC or CTNNB1 (β-catenin) is rare in breast cancer, activation of Wnt signalling is nonetheless thought to play an important role in breast tumorigenesis, and epigenetic silencing of Wnt antagonist genes, including the secreted frizzled-related protein (SFRP) and Dickkopf (DKK) families, has been observed in various tumours. In breast cancer, frequent methylation and silencing of SFRP1 was recently documented; however, altered expression of other Wnt antagonist genes is largely unknown. In the present study, we found frequent methylation of SFRP family genes in breast cancer cell lines (SFRP1, 7 out of 11, 64%; SFRP2, 11 out of 11, 100%; SFRP5, 10 out of 11, 91%) and primary breast tumours (SFRP1, 31 out of 78, 40%; SFRP2, 60 out of 78, 77%; SFRP5, 55 out of 78, 71%). We also observed methylation of DKK1, although less frequently, in cell lines (3 out of 11, 27%) and primary tumours (15 out of 78, 19%). Breast cancer cell lines express various Wnt ligands, and overexpression of SFRPs inhibited cancer cell growth. In addition, overexpression of a β-catenin mutant and depletion of SFRP1 using small interfering RNA synergistically upregulated transcriptional activity of T-cell factor/lymphocyte enhancer factor. Our results confirm the frequent methylation and silencing of Wnt antagonist genes in breast cancer, and suggest that their loss of function contributes to activation of Wnt signalling in breast carcinogenesis. PMID:18283316

  6. Peptide Antibiotics for ESKAPE Pathogens

    DEFF Research Database (Denmark)

    Thomsen, Thomas Thyge

    Multi-drug resistance to antibiotics represents a global health challenge that results in increased morbidity and mortality rates. The annual death-toll is >700.000 people world-wide, rising to ~10 million by 2050. New antibiotics are lacking, and few are under development as return on investment...... is considered poor compared to medicines for lifestyle diseases. According to the WHO we could be moving towards a post-antibiotic era in which previously treatable infections become fatal. Of special importance are multidrug resistant bacteria from the ESKAPE group (Enterococcus faecium, Staphylococcus aureus...... and toxicity by utilizing of the fruit fly Drosophila melanogaster as a whole animal model. This was carried out by testing of antimicrobial peptides targeting Gram-positive bacteria exemplified by the important human pathogen methicillin resistant S. aureus (MRSA). The peptide BP214 was developed from...

  7. Short Communication: Inhibition of DC-SIGN-Mediated HIV-1 Infection by Complementary Actions of Dendritic Cell Receptor Antagonists and Env-Targeting Virus Inactivators.

    Science.gov (United States)

    Pustylnikov, Sergey; Dave, Rajnish S; Khan, Zafar K; Porkolab, Vanessa; Rashad, Adel A; Hutchinson, Matthew; Fieschi, Frank; Chaiken, Irwin; Jain, Pooja

    2016-01-01

    The DC-SIGN receptor on human dendritic cells interacts with HIV gp120 to promote both infection of antigen-presenting cells and transinfection of T cells. We hypothesized that in DC-SIGN-expressing cells, both DC-SIGN ligands such as dextrans and gp120 antagonists such as peptide triazoles would inhibit HIV infection with potential complementary antagonist effects. To test this hypothesis, we evaluated the effects of dextran (D66), isomaltooligosaccharides (D06), and several peptide triazoles (HNG156, K13, and UM15) on HIV infection of B-THP-1/DC-SIGN cells. In surface plasmon resonance competition assays, D66 (IC50 = 35.4 μM) and D06 (IC50 = 3.4 mM) prevented binding of soluble DC-SIGN to immobilized mannosylated bovine serum albumin (BSA). An efficacious dose-dependent inhibition of DC-SIGN-mediated HIV infection in both pretreatment and posttreatment settings was observed, as indicated by inhibitory potentials (EC50) [D66 (8 μM), D06 (48 mM), HNG156 (40 μM), UM15 (100 nM), and K13 (25 nM)]. Importantly, both dextrans and peptide triazoles significantly decreased HIV gag RNA levels [D66 (7-fold), D06 (13-fold), HNG156 (7-fold), K-13 (3-fold), and UM15 (6-fold)]. Interestingly, D06 at the highest effective concentration showed a 14-fold decrease of infection, while its combination with 50 μM HNG156 showed a 26-fold decrease. Hence, these compounds can combine to inactivate the viruses and suppress DC-SIGN-mediated virus-cell interaction that as shown earlier leads to dendritic cell HIV infection and transinfection dependent on the DC-SIGN receptor.

  8. Peptide-targeted polymer cancerostatics

    Czech Academy of Sciences Publication Activity Database

    Böhmová, Eliška; Pola, Robert

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S153-S164 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : HPMA copolymers * tumor targeting * peptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S153.pdf

  9. Biopharmaceuticals: From peptide to drug

    Science.gov (United States)

    Hannappel, Margarete

    2017-08-01

    Biologics are therapeutic proteins or peptides that are produced by means of biological processes within living organisms and cells. They are highly specific molecules and play a crucial role as therapeutics for the treatment of severe and chronic diseases (e.g. cancer, rheumatoid arthritis, diabetes, autoimmune disorders). The development of new biologics and biologics-based drugs gains more and more importance in the fight against various diseases. A short overview on biotherapeutical drug development is given. Cone snails are a large group of poisonous, predatory sea snails with more than 700 species. They use a very powerful venom which rapidly inactivates and paralyzes their prey. Most bioactive venom components are small peptides (conotoxins, conopeptides) which are precisely directed towards a specific target (e.g. ion channel, receptors). Due to their small size, their precision and speed of action, naturally occurring cone snail venom peptides represent an attractive source for the identification and design of novel biological drug entities. The Jagna cone snail project is an encouraging initiative to map the ecological variety of cone snails around the island of Bohol (Philippines) and to conserve the biological information for potential future application.

  10. Coffee, hunger, and peptide YY.

    Science.gov (United States)

    Greenberg, James A; Geliebter, Allan

    2012-06-01

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

  11. Antimicrobial Peptides: Versatile Biological Properties

    Directory of Open Access Journals (Sweden)

    Muthuirulan Pushpanathan

    2013-01-01

    Full Text Available Antimicrobial peptides are diverse group of biologically active molecules with multidimensional properties. In recent past, a wide variety of AMPs with diverse structures have been reported from different sources such as plants, animals, mammals, and microorganisms. The presence of unusual amino acids and structural motifs in AMPs confers unique structural properties to the peptide that attribute for their specific mode of action. The ability of these active AMPs to act as multifunctional effector molecules such as signalling molecule, immune modulators, mitogen, antitumor, and contraceptive agent makes it an interesting candidate to study every aspect of their structural and biological properties for prophylactic and therapeutic applications. In addition, easy cloning and recombinant expression of AMPs in heterologous plant host systems provided a pipeline for production of disease resistant transgenic plants. Besides these properties, AMPs were also used as drug delivery vectors to deliver cell impermeable drugs to cell interior. The present review focuses on the diversity and broad spectrum antimicrobial activity of AMPs along with its multidimensional properties that could be exploited for the application of these bioactive peptides as a potential and promising drug candidate in pharmaceutical industries.

  12. Abiotic conditions affect floral antagonists and mutualists of Impatiens capensis (Balsaminaceae).

    Science.gov (United States)

    Soper Gorden, Nicole L; Adler, Lynn S

    2013-04-01

    While the effect of abiotic factors on leaf herbivory is well known, the relative importance of abiotic conditions influencing both mutualists and antagonists is less well understood. Species interactions could enhance or reduce the direct effects of abiotic factors, depending on how mutualists and antagonists respond to abiotic conditions. We manipulated soil nutrients and shade in a factorial design and measured soil moisture in the annual Impatiens capensis. We then measured interactions with mutualists (two pollinating species) and antagonists (herbivores, florivores, nectar thieves, and flower bud gallers), as well as plant growth, floral rewards, and plant reproduction. Fertilizer increased plant growth, floral attractiveness, mutualist and antagonist interactions, and plant reproduction. Shade had no effects, and soil moisture was negatively associated with plant growth and reproduction. All effects were additive. Mutualist and antagonist floral interactions both increased on fertilized plants, but antagonists increased at a greater rate, leading to a larger ratio of antagonist to mutualist interactions on fertilized plants. Despite having more antagonists, fertilized plants still had significantly higher reproduction, suggesting higher tolerance to antagonists. Abiotic effects can have consistent effects on antagonists and mutualists, and on both floral and leaf antagonists. However, tolerance to antagonisms increased in favorable conditions. Thus, the direct positive effects of favorable abiotic conditions on plants outweighed negative indirect effects via increased antagonisms, which may lead to selection to grow in high-nutrient microsites in spite of increased herbivory.

  13. Chemical methods for peptide and protein production.

    Science.gov (United States)

    Chandrudu, Saranya; Simerska, Pavla; Toth, Istvan

    2013-04-12

    Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported α-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

  14. Prediction of twin-arginine signal peptides

    Directory of Open Access Journals (Sweden)

    Widdick David

    2005-07-01

    Full Text Available Abstract Background Proteins carrying twin-arginine (Tat signal peptides are exported into the periplasmic compartment or extracellular environment independently of the classical Sec-dependent translocation pathway. To complement other methods for classical signal peptide prediction we here present a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than a complementary rule based prediction method. Conclusion The method developed here is able to discriminate Tat signal peptides from cytoplasmic proteins carrying a similar motif, as well as from Sec signal peptides, with high accuracy. The method allows filtering of input sequences based on Perl syntax regular expressions, whereas hydrophobicity discrimination of Tat- and Sec-signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/.

  15. Chemical Methods for Peptide and Protein Production

    Directory of Open Access Journals (Sweden)

    Istvan Toth

    2013-04-01

    Full Text Available Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported a-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

  16. Natriuretic Peptides: Biochemistry, Physiology, Clinical Implication

    Directory of Open Access Journals (Sweden)

    I. A. Kozlova

    2009-01-01

    Full Text Available In the past years, the interest of theorists and clinicians has steadily increased in the myocardially secreted hormones – natriuretic peptides. At the Congress of the European Society of Anesthesiology (Munich, 2007, B-type natriuretic peptides were included into the list of the parameters of perioperative laboratory monitoring that is expedient in the practice of anesthetists and resuscitation specialists. The literature review shows the history of discovery and identification of different types of natriuretic peptides and considers the matters of their biochemistry. It also details information on the synthesis, secretion, and clearance of these peptides, as well as their receptor apparatus in various organs and tissues. The physiology of the regulatory system is described, as applied to the cardiovascular, excretory, central nervous systems, and the neuroendocrine one. Special attention is given to the current publications on the control of B-type natriuretic peptides as biomarkers of cardiac dysfunction. The diagnostic and prognostic values of peptides are analyzed in chronic circulatory insufficiency, coronary heart disease, and other car-diological and non-cardiological diseases. The prognostic value of elevated B-type natriuretic peptide levels in cardiac surgery is separately considered. It is concluded that the changes in the level of B-type natriuretic peptides in different clinical situations are the subject of numerous researches mainly made in foreign countries. The bulk of these researches are devoted to the study of peptides in cardiology and other areas of therapy. Studies on the use of peptides in reanimatology are relatively few and their results are rather discordant. The foregoing opens up wide prospects for studying the use of B-type natriuretic peptides in Russian intensive care and anesthesiology. Key words: natriuretic peptides, brain nautriuretic peptides, NT-proBNP.

  17. THE EFFECTS OF ACHETA DIURETIC PEPTIDE ON ISOLATED MALPIGHIAN TUBULES FROM THE HOUSE CRICKET ACHETA DOMESTICUS

    Science.gov (United States)

    Coast; Kay

    1994-02-01

    Acheta diuretic peptide (Acheta-DP) is a corticotropin-releasing factor (CRF)-related peptide found in head extracts of the house cricket Acheta domesticus. The peptide causes a dose-dependent increase in fluid secretion by cricket Malpighian tubules isolated in vitro, and the apparent EC50 is 1.3 nmol l-1, which is within the physiological range for a peptide hormone. The CRF antagonist alpha-helical CRF(9-41) blocks the action of Acheta-DP in a dose-dependent manner, and the IC50 is estimated to be in the micromolar range. Addition of Acheta-DP to isolated Malpighian tubules is followed by a rapid and marked increase in the level of intracellular cyclic AMP. This precedes any change in voltage or fluid secretion, which strongly suggests that cyclic AMP is the intracellular mediator of Acheta-DP activity. Consistent with this, diuretic activity is potentiated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, and there is a close relationship between the dose­response curves for cyclic AMP production and for fluid secretion. However, exogenous 8-bromo-cyclic AMP does not mimic all the effects of Acheta-DP, and the peptide may have a dual action on isolated tubules. Fluid secretion by tubules dosed repeatedly with Acheta-DP returns to near basal levels after 3­5 h. This cannot be explained by degradation of the peptide, but might be due in part to oxygen and/or metabolite deficiency. However, tubules that are refractory to Acheta-DP can be stimulated by forskolin, 8-bromo-cyclic AMP and extracts of corpora cardiaca, which is indicative of a homologous desensitization of membrane receptors for the diuretic peptide. Differences in the rate of secretion by morphologically distinct regions of cricket Malpighian tubules have been assessed. In unstimulated tubules, the rate of secretion per unit length by the short distal segment is about twice that of the main tubule. However, diuretic peptides (Acheta-DP and achetakinin-I) have little effect on distal

  18. Brain penetrant small molecule 18F-GnRH receptor (GnRH-R) antagonists: Synthesis and preliminary positron emission tomography imaging in rats

    International Nuclear Information System (INIS)

    Olberg, Dag E.; Bauer, Nadine; Andressen, Kjetil W.; Hjørnevik, Trine; Cumming, Paul; Levy, Finn O.; Klaveness, Jo; Haraldsen, Ira; Sutcliffe, Julie L.

    2016-01-01

    Introduction: The gonadotropin releasing hormone receptor (GnRH-R) has a well-described neuroendocrine function in the anterior pituitary. However, little is known about its function in the central nervous system (CNS), where it is most abundantly expressed in hippocampus and amygdala. Since peptide ligands based upon the endogenous decapetide GnRH do not pass the blood–brain-barrier, we are seeking a high-affinity small molecule GnRH-R ligand suitable for brain imaging by positron emission tomography. We have previously reported the radiosynthesis and in vitro evaluation of two novel [ 18 F]fluorinated GnRH-R ligands belonging to the furamide class of antagonists, with molecular weight less than 500 Da. We now extend this work using palladium coupling for the synthesis of four novel radioligands, with putatively reduced polar surface area and hydrophilicity relative to the two previously described compounds, and report the uptake of these 18 F-labeled compounds in brain of living rats. Methods: We synthesized reference standards of the small molecule GnRH-R antagonists as well as mesylate precursors for 18 F-labeling. The antagonists were tested for binding affinity for both human and rat GnRH-R. Serum and blood stability in vitro and in vivo were studied. Biodistribution and PET imaging studies were performed in male rats in order to assess brain penetration in vivo. Results: A palladium coupling methodology served for the synthesis of four novel fluorinated furamide GnRH receptor antagonists with reduced heteroatomic count. Radioligand binding assays in vitro revealed subnanomolar affinity of the new fluorinated compounds for both human and rat GnRH-R. The 18 F-GnRH antagonists were synthesized from the corresponding mesylate precursors in 5–15% overall radiochemical yield. The radiolabeled compounds demonstrated good in vivo stability. PET imaging with the 18 F-radiotracers in naive rats showed good permeability into brain and rapid washout, but absence of

  19. Human Antimicrobial Peptides and Proteins

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2014-05-01

    Full Text Available As the key components of innate immunity, human host defense antimicrobial peptides and proteins (AMPs play a critical role in warding off invading microbial pathogens. In addition, AMPs can possess other biological functions such as apoptosis, wound healing, and immune modulation. This article provides an overview on the identification, activity, 3D structure, and mechanism of action of human AMPs selected from the antimicrobial peptide database. Over 100 such peptides have been identified from a variety of tissues and epithelial surfaces, including skin, eyes, ears, mouths, gut, immune, nervous and urinary systems. These peptides vary from 10 to 150 amino acids with a net charge between −3 and +20 and a hydrophobic content below 60%. The sequence diversity enables human AMPs to adopt various 3D structures and to attack pathogens by different mechanisms. While α-defensin HD-6 can self-assemble on the bacterial surface into nanonets to entangle bacteria, both HNP-1 and β-defensin hBD-3 are able to block cell wall biosynthesis by binding to lipid II. Lysozyme is well-characterized to cleave bacterial cell wall polysaccharides but can also kill bacteria by a non-catalytic mechanism. The two hydrophobic domains in the long amphipathic α-helix of human cathelicidin LL-37 lays the basis for binding and disrupting the curved anionic bacterial membrane surfaces by forming pores or via the carpet model. Furthermore, dermcidin may serve as ion channel by forming a long helix-bundle structure. In addition, the C-type lectin RegIIIα can initially recognize bacterial peptidoglycans followed by pore formation in the membrane. Finally, histatin 5 and GAPDH(2-32 can enter microbial cells to exert their effects. It appears that granulysin enters cells and kills intracellular pathogens with the aid of pore-forming perforin. This arsenal of human defense proteins not only keeps us healthy but also inspires the development of a new generation of personalized

  20. Oil-based formulation as a sustained-released injection for a novel synthetic peptide.

    Science.gov (United States)

    Zhang, Guiying; Li, Jinglai; Wang, Tao; Gao, Lijun; Quan, Dongqin

    2015-01-01

    In this study, sustained-release of GnRH antagonist peptide LXT-101 was realized through oil formulation, and their releasing characteristics in vitro and in vivo were investigated. In this formulation, the static interaction between cationic charged peptide LXT-101 and the negative charged phospholipid led to the formation of the phospholipid-peptide complex, by which LXT-101 was completely dissolved in oils. This formulation was prepared by mixing an aqueous solution of LXT-101 and empty SUV (small unilamellar liposomes) containing EPC (phosphatidylcholine) and DPPG (1, 2-dipalmitog-sn-glycero-3- phosphoglycerol) at an appropriate ratio, the mixture was subsequently lyophilized, and the resultant was dissolved in the oil to form a clear oily solution containing solubilized peptide LXT-101. With atomic force microscopy combined with Langmuir-Blodgett technology, the morphology of the particles in the oily solution were examined to be oval-shaped and the mean particle size was 150 nm in diameter. In pure water at 37°C, about 70~90 % of LXT-101 was released slowly from the oily formulation over 7 days. An effective sustained suppression of testosterone in beagle dogs could be achieved over a period of seven days with this LXT-101 oily formulation, by i.m. at a dose of 0.2 mg/kg (2 mg/ml). This formulation dramatically improved the bioactivity of LXT-101 compared to its aqueous solution. It was also found that when the concentration of peptide LXT-101 was up to or over 10 mg/ml in aqueous solution, there was no significant difference between the oily formulation and aqueous solution. This fact meant that LXT-101 itself could conduct sustained release in vivo by self-assembly of nanofibers.

  1. Opioid peptides inhibit intestinal transit in the rat by a central mechanism.

    Science.gov (United States)

    Galligan, J J; Burks, T F

    1982-11-05

    Opiates and opioid peptides can alter gastrointestinal motility and delay transit of intraluminal contents. These experiments were designed to characterize the effects of beta-endorphin and [D-Ala2,Met5]enkephalinamide (DALA) on small intestinal transit in the rat. Rats were implanted with a polyethylene cannula in the right lateral cerebral ventricle and a silastic cannula in the proximal duodenum. Drugs were administered via the cerebral cannula or intraperitoneally (i.p.) Interstitial transit was assessed by instilling radiochromium into the duodenum and calculating the geometric center of the distribution of marker in the small intestine. beta-Endorphin and DALA produced a dose-related decrease in intestinal transit when the peptides were given intracerebroventricularly (i.c.v.) however, neither peptide was effective when i.p. [D-Ala2,Leu5]enkephalinamide and dynorphin-(1-13) did not alter intestinal transit. The inhibitory effects of beta-endorphin and DALA were antagonized by pretreatment with naloxone or naltrexone. A quaternary amine containing opiate antagonist. N,N-diallylnormorphinium given i.p. did not alter the response to either peptide but was effective in blocking the antitransit effects of i.p. loperamide, a peripherally acting opioid agonist. In addition, DALA reduced the body weight loss produced by castor oil-induced diarrhea while beta-endorphin had no effect. These results indicate that opioid peptides can alter intestinal motility by an action within the central nervous system. While DALA and beta-endorphin produce quantitatively the same effects on small intestinal motility, qualitatively they may differ in their mechanisms of action.

  2. Discovery and Characterization of a Potent Interleukin-6 Binding Peptide with Neutralizing Activity In Vivo.

    Directory of Open Access Journals (Sweden)

    Sheila Ranganath

    Full Text Available Interleukin-6 (IL-6 is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman's Disease (CD and rheumatoid arthritis (RA. Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA and C-reactive protein (CRP. This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology.

  3. Discovery and Characterization of a Potent Interleukin-6 Binding Peptide with Neutralizing Activity In Vivo

    Science.gov (United States)

    Ranganath, Sheila; Bhandari, Ashok; Avitahl-Curtis, Nicole; McMahon, Jaimee; Wachtel, Derek; Zhang, Jenny; Leitheiser, Christopher; Bernier, Sylvie G.; Liu, Guang; Tran, Tran T.; Celino, Herodion; Tobin, Jenny; Jung, Joon; Zhao, Hong; Glen, Katie E.; Graul, Chris; Griffin, Aliesha; Schairer, Wayne C.; Higgins, Carolyn; Reza, Tammi L.; Mowe, Eva; Rivers, Sam; Scott, Sonya; Monreal, Alex; Shea, Courtney; Bourne, Greg; Coons, Casey; Smith, Adaline; Tang, Kim; Mandyam, Ramya A.; Masferrer, Jaime; Liu, David; Patel, Dinesh V.; Fretzen, Angelika; Murphy, Craig A.; Milne, G. Todd; Smythe, Mark L.; Carlson, Kenneth E.

    2015-01-01

    Interleukin-6 (IL-6) is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman’s Disease (CD) and rheumatoid arthritis (RA). Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R)/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs) directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs) directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK) profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG) moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA) and C-reactive protein (CRP). This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology. PMID:26555695

  4. Heat hyperalgesia and mechanical hypersensitivity induced by calcitonin gene-related peptide in a mouse model of neurofibromatosis.

    Directory of Open Access Journals (Sweden)

    Stephanie White

    Full Text Available This study examined whether mice with a deficiency of neurofibromin, a Ras GTPase activating protein, exhibit a nociceptive phenotype and probed a possible contribution by calcitonin gene-related peptide. In the absence of inflammation, Nf1+/- mice (B6.129S6 Nf1/J and wild type littermates responded comparably to heat or mechanical stimuli, except for a subtle enhanced mechanical sensitivity in female Nf1+/- mice. Nociceptive phenotype was also examined after inflammation induced by capsaicin and formalin, which release endogenous calcitonin gene-related peptide. Intraplantar injection of capsaicin evoked comparable heat hyperalgesia and mechanical hypersensitivity in Nf1+/- and wild type mice of both genders. Formalin injection caused a similar duration of licking in male Nf1+/- and wild type mice. Female Nf1+/- mice licked less than wild type mice, but displayed other nociceptive behaviors. In contrast, intraplantar injection of CGRP caused greater heat hyperalgesia in Nf1+/- mice of both genders compared to wild type mice. Male Nf1+/- mice also exhibited greater mechanical hypersensitivity; however, female Nf1+/- mice exhibited less mechanical hypersensitivity than their wild type littermates. Transcripts for calcitonin gene-related peptide were similar in the dorsal root ganglia of both genotypes and genders. Transcripts for receptor activity-modifying protein-1, which is rate-limiting for the calcitonin gene-related peptide receptor, in the spinal cord were comparable for both genotypes and genders. The increased responsiveness to intraplantar calcitonin gene-related peptide suggests that the peripheral actions of calcitonin gene-related peptide are enhanced as a result of the neurofibromin deficit. The analgesic efficacy of calcitonin gene-related peptide receptor antagonists may therefore merit investigation in neurofibromatosis patients.

  5. Heat hyperalgesia and mechanical hypersensitivity induced by calcitonin gene-related peptide in a mouse model of neurofibromatosis.

    Science.gov (United States)

    White, Stephanie; Marquez de Prado, Blanca; Russo, Andrew F; Hammond, Donna L

    2014-01-01

    This study examined whether mice with a deficiency of neurofibromin, a Ras GTPase activating protein, exhibit a nociceptive phenotype and probed a possible contribution by calcitonin gene-related peptide. In the absence of inflammation, Nf1+/- mice (B6.129S6 Nf1/J) and wild type littermates responded comparably to heat or mechanical stimuli, except for a subtle enhanced mechanical sensitivity in female Nf1+/- mice. Nociceptive phenotype was also examined after inflammation induced by capsaicin and formalin, which release endogenous calcitonin gene-related peptide. Intraplantar injection of capsaicin evoked comparable heat hyperalgesia and mechanical hypersensitivity in Nf1+/- and wild type mice of both genders. Formalin injection caused a similar duration of licking in male Nf1+/- and wild type mice. Female Nf1+/- mice licked less than wild type mice, but displayed other nociceptive behaviors. In contrast, intraplantar injection of CGRP caused greater heat hyperalgesia in Nf1+/- mice of both genders compared to wild type mice. Male Nf1+/- mice also exhibited greater mechanical hypersensitivity; however, female Nf1+/- mice exhibited less mechanical hypersensitivity than their wild type littermates. Transcripts for calcitonin gene-related peptide were similar in the dorsal root ganglia of both genotypes and genders. Transcripts for receptor activity-modifying protein-1, which is rate-limiting for the calcitonin gene-related peptide receptor, in the spinal cord were comparable for both genotypes and genders. The increased responsiveness to intraplantar calcitonin gene-related peptide suggests that the peripheral actions of calcitonin gene-related peptide are enhanced as a result of the neurofibromin deficit. The analgesic efficacy of calcitonin gene-related peptide receptor antagonists may therefore merit investigation in neurofibromatosis patients.

  6. Oxytocin in the periaqueductal gray participates in pain modulation in the rat by influencing endogenous opiate peptides.

    Science.gov (United States)

    Yang, Jun; Liang, Jin-Ying; Li, Peng; Pan, Yan-Juan; Qiu, Pei-Yong; Zhang, Jing; Hao, Fang; Wang, Da-Xin

    2011-06-01

    Periaqueductal gray (PAG) plays a very important role in pain modulation through endogenous opiate peptides including leucine-enkephalin (L-Ek), methionine-enkephalin (M-Ek), β-endorphin (β-Ep) and dynorphin A(1-13) (DynA(1-13)). Our pervious study has demonstrated that intra-PAG injection of oxytocin (OXT) increases the pain threshold, and local administration of OXT receptor antagonist decreases the pain threshold, in which the antinociceptive role of OXT can be reversed by pre-PAG administration of OXT receptor antagonist. The experiment was designed to investigate the effect of OXT on endogenous opiate peptides in the rat PAG during the pain process. The results showed that (1) the concentrations of OXT, L-Ek, M-Ek and β-Ep, not DynA(1-13) in the PAG perfusion liquid were increased after the pain stimulation; (2) the concentrations of L-Ek, M-Ek and β-Ep, not DynA(1-13) in the PAG perfusion liquid were decreased by the OXT receptor antagonist; (3) the increased pain threshold induced by the OXT was attenuated by naloxone, an opiate receptor antagonist; and (4) the concentrations of L-Ek, M-Ek and β-Ep, not DynA(1-13) in the PAG perfusion liquid were increased by exogenous OXT administration. The data suggested that OXT in the PAG could influence the L-Ek, M-Ek and β-Ep rather than DynA(1-13) to participate in pain modulation, i.e. OXT in the PAG participate in pain modulation by influencing the L-Ek, M-Ek and β-Ep rather than DynA(1-13). Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Potent peptidic fusion inhibitors of influenza virus

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-28

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

  8. Designing anticancer peptides by constructive machine learning.

    Science.gov (United States)

    Grisoni, Francesca; Neuhaus, Claudia; Gabernet, Gisela; Müller, Alex; Hiss, Jan; Schneider, Gisbert

    2018-04-21

    Constructive machine learning enables the automated generation of novel chemical structures without the need for explicit molecular design rules. This study presents the experimental application of such a generative model to design membranolytic anticancer peptides (ACPs) de novo. A recurrent neural network with long short-term memory cells was trained on alpha-helical cationic amphipathic peptide sequences and then fine-tuned with 26 known ACPs. This optimized model was used to generate unique and novel amino acid sequences. Twelve of the peptides were synthesized and tested for their activity on MCF7 human breast adenocarcinoma cells and selectivity against human erythrocytes. Ten of these peptides were active against cancer cells. Six of the active peptides killed MCF7 cancer cells without affecting human erythrocytes with at least threefold selectivity. These results advocate constructive machine learning for the automated design of peptides with desired biological activities. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Prediction of twin-arginine signal peptides

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; Widdick, D.

    2005-01-01

    a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results: We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal...... peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than...... expressions, whereas hydrophobicity discrimination of Tat- and Sec- signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/....

  10. Second extracellular loop of human glucagon-like peptide-1 receptor (GLP-1R) has a critical role in GLP-1 peptide binding and receptor activation.

    Science.gov (United States)

    Koole, Cassandra; Wootten, Denise; Simms, John; Miller, Laurence J; Christopoulos, Arthur; Sexton, Patrick M

    2012-02-03

    The glucagon-like peptide-1 receptor (GLP-1R) is a therapeutically important family B G protein-coupled receptor (GPCR) that is pleiotropically coupled to multiple signaling effectors and, with actions including regulation of insulin biosynthesis and secretion, is one of the key targets in the management of type II diabetes mellitus. However, there is limited understanding of the role of the receptor core in orthosteric ligand binding and biological activity. To assess involvement of the extracellular loop (ECL) 2 in ligand-receptor interactions and receptor activation, we performed alanine scanning mutagenesis of loop residues and assessed the impact on receptor expression and GLP-1(1-36)-NH(2) or GLP-1(7-36)-NH(2) binding and activation of three physiologically relevant signaling pathways as follows: cAMP formation, intracellular Ca(2+) (Ca(2+)(i)) mobilization, and phosphorylation of extracellular signal-regulated kinases 1 and 2 (pERK1/2). Although antagonist peptide binding was unaltered, almost all mutations affected GLP-1 peptide agonist binding and/or coupling efficacy, indicating an important role in receptor activation. However, mutation of several residues displayed distinct pathway responses with respect to wild type receptor, including Arg-299 and Tyr-305, where mutation significantly enhanced both GLP-1(1-36)-NH(2)- and GLP-1(7-36)-NH(2)-mediated signaling bias for pERK1/2. In addition, mutation of Cys-296, Trp-297, Asn-300, Asn-302, and Leu-307 significantly increased GLP-1(7-36)-NH(2)-mediated signaling bias toward pERK1/2. Of all mutants studied, only mutation of Trp-306 to alanine abolished all biological activity. These data suggest a critical role of ECL2 of the GLP-1R in the activation transition(s) of the receptor and the importance of this region in the determination of both GLP-1 peptide- and pathway-specific effects.

  11. Rubimetide, humanin, and MMK1 exert anxiolytic-like activities via the formyl peptide receptor 2 in mice followed by the successive activation of DP1, A2A, and GABAA receptors.

    Science.gov (United States)

    Zhao, Hui; Sonada, Soushi; Yoshikawa, Akihiro; Ohinata, Kousaku; Yoshikawa, Masaaki

    2016-09-01

    Rubimetide (Met-Arg-Trp), which had been isolated as an antihypertensive peptide from an enzymatic digest of spinach ribulose-bisphosphate carboxylase/oxygenase (Rubisco), showed anxiolytic-like activity prostaglandin (PG) D2-dependent manner in the elevated plus-maze test after administration at a dose of 0.1mg/kg (ip.) or 1mg/kg (p.o.) in male mice of ddY strain. In this study, we found that rubimetide has weak affinities for the FPR1 and FPR2, subtypes of formyl peptide receptor (FPR). The anxiolytic-like activity of rubimetide (0.1mg/kg, ip.) was blocked by WRW4, an antagonist of FPR2, but not by Boc-FLFLF, an antagonist of FPR1, suggesting that the anxiolytic-like activity was mediated by the FPR2. Humanin, an endogenous agonist peptide of the FPR2, exerted an anxiolytic-like activity after intracerebroventricular (icv) administration, which was also blocked by WRW4. MMK1, a synthetic agonist peptide of the FPR2, also exerted anxiolytic-like activity. Thus, FPR2 proved to mediate anxiolytic-like effect as the first example of central effect exerted by FPR agonists. As well as the anxiolytic-like activity of rubimetide, that of MMK1 was blocked by BW A868C, an antagonist of the DP1-receptor. Furthermore, anxiolytic-like activity of rubimetide was blocked by SCH58251 and bicuculline, antagonists for adenosine A2A and GABAA receptors, respectively. From these results, it is concluded that the anxiolytic-like activities of rubimetide and typical agonist peptides of the FPR2 were mediated successively by the PGD2-DP1 receptor, adenosine-A2A receptor, and GABA-GABAA receptor systems downstream of the FPR2. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Predictions of in vivo prolactin levels from in vitro k I values of d 2 receptor antagonists using an agonist-antagonist interaction model

    NARCIS (Netherlands)

    Petersson, K.J.; Vermeulen, A.M.J.; Friberg, L.E.

    2013-01-01

    Prolactin elevation is a side effect of all currently available D2 receptor antagonists used in the treatment of schizophrenia. Prolactin elevation is the result of a direct antagonistic D2 effect blocking the tonic inhibition of prolactin release by dopamine. The aims of this work were to assess

  13. Use of Galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2016-03-01

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  14. Use of Galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2017-03-21

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  15. Use of galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2018-04-03

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

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

    DEFF Research Database (Denmark)

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

    1990-01-01

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

  17. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... attempts have been made to couple peptide immunogens to different carrier proteins [e.g. keyhole limper haemocyanin (KLH) or ovalbumin]. This leads to very complex structures, however. We used a controlled conjugation of a peptide to a single long-chain fatty acid like palmitic acid by a thioester...... or an amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  18. An Evaluation of Peptide-Bond Isosteres

    OpenAIRE

    Choudhary, Amit; Raines, Ronald T.

    2011-01-01

    Peptide-bond isosteres can enable a deep interrogation of the structure and function of a peptide or protein by amplifying or attenuating particular chemical properties. In this minireview, the electronic, structural, and conformational attributes of four such isosteres—thioamides, esters, alkenes, and fluoroalkenes—are examined in detail. In particular, the ability of these isosteres to partake in noncovalent interactions is compared with that of the peptide bond. The consequential perturbat...

  19. VIP and endothelin receptor antagonist: An effective combination against experimental pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Szema Anthony M

    2011-10-01

    Full Text Available Abstract Background Pulmonary Arterial Hypertension (PAH remains a therapeutic challenge, and the search continues for more effective drugs and drug combinations. We recently reported that deletion of the vasoactive intestinal peptide (VIP gene caused the spontaneous expression of a PH phenotype that was fully corrected by VIP. The objectives of this investigation were to answer the questions: 1 Can VIP protect against PH in other experimental models? and 2 Does combining VIP with an endothelin (ET receptor antagonist bosentan enhance its efficacy? Methods Within 3 weeks of a single injection of monocrotaline (MCT, s.c. in Sprague Dawley rats, PAH developed, manifested by pulmonary vascular remodeling, lung inflammation, RV hypertrophy, and death within the next 2 weeks. MCT-injected animals were either untreated, treated with bosentan (p.o. alone, with VIP (i.p. alone, or with both together. We selected this particular combination upon finding that VIP down-regulates endothelin receptor expression which is further suppressed by bosentan. Therapeutic outcomes were compared as to hemodynamics, pulmonary vascular pathology, and survival. Results Treatment with VIP, every other day for 3 weeks, begun on the same day as MCT, almost totally prevented PAH pathology, and eliminated mortality for 45 days. Begun 3 weeks after MCT, however, VIP only partially reversed PAH pathology, though more effectively than bosentan. Combined therapy with both drugs fully reversed the pathology, while preventing mortality for at least 45 days. Conclusions 1 VIP completely prevented and significantly reversed MCT-induced PAH; 2 VIP was more effective than bosentan, probably because it targets a wider range of pro-remodeling pathways; and 3 combination therapy with VIP plus bosentan was more effective than either drug alone, probably because both drugs synergistically suppressed ET-ET receptor pathway.

  20. Restriction of anti-peptide antibody specificity by enzyme-modified Sepharose-peptide immunoadsorbents.

    Science.gov (United States)

    Trinca, M L; Muratti, E; Camera, M; Chersi, A

    1988-06-01

    Sepharose-peptide immunoadsorbents, employed for the isolation of specific antibodies from the sera of rabbits immunized with carrier protein-peptide conjugates, were digested with suitable proteolytic enzymes, in order to obtain the splitting of a part of the peptide bound to the gel. This new modified immunoadsorbent can be advantageously used for the isolation of antibody subsets, that do not cross-react with related peptides exhibiting high sequence homology with the immunogens.

  1. Novel peptide-based protease inhibitors

    DEFF Research Database (Denmark)

    Roodbeen, Renée

    This thesis describes the design and synthesis of peptide-based serine protease inhibitors. The targeted protease, urokinase-type plasminogen activator (uPA) activates plasminogen, which plays a major role in cancer metastasis. The peptide upain-2 (S 1 ,S 12-cyclo-AcCSWRGLENHAAC-NH2) is a highly...... of novel peptide-based protease inhibitors, efforts were made towards improved methods for peptide synthesis. The coupling of Fmoc-amino acids onto N-methylated peptidyl resins was investigated. These couplings can be low yielding and the effect of the use of microwave heating combined with the coupling...

  2. Endogenous Glucagon-Like Peptide-1 Reduces Drinking Behavior and Is Differentially Engaged by Water and Food Intakes in Rats

    OpenAIRE

    McKay, Naomi J.; Galante, Daniela L.; Daniels, Derek

    2014-01-01

    Glucagon-like peptide-1 (GLP-1) is produced in the ileum and the nucleus of the solitary tract. It is well known that GLP-1 controls food intake, but there is a growing literature indicating that GLP-1 also is involved in fluid intake. It is not known, however, if the observed effects are pharmacological or if endogenous GLP-1 and its receptor contribute to physiological fluid intake control. Accordingly, we blocked endogenous GLP-1 by application of a receptor antagonist and measured subsequ...

  3. Isolation and identification of antifungal peptides from Bacillus amyloliquefaciens W10.

    Science.gov (United States)

    Zhang, Qing-Xia; Zhang, Ying; Shan, Hai-Huan; Tong, Yun-Hui; Chen, Xi-Jun; Liu, Feng-Quan

    2017-11-01

    Antifungal metabolites produced by Bacillus sp. W10, which was previously isolated from the tomato rhizosphere, were investigated. Strain W10 was identified as Bacillus amyloliquefaciens by analysis of its 16S rDNA and gyrB gene partial sequences. PCR analysis showed the presence of fenB, sfp, and ituD genes, coding for fengycin, surfactin, and iturin, respectively. A novel small antifungal peptide, designated 5240, produced by this strain was isolated by ammonium sulfate precipitation and Superdex 200 gel filtration chromatography. The 5240 peptide was stable at 100 °C for 20 min and remained active throughout a wide pH range (4-10). The antagonistic activity was not affected by protease K and trypsin. The purified 5240 peptide exhibited a broad inhibitory spectrum against various plant pathogenic fungi and was identified as iturin A (C 14 -C 16 ). Moreover, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry indicated the presence of fengycin A (C 14 -C 15 ), fengycin B (C 16 -C 17 ), and surfactin (C 13 -C 16 ) isoforms in supernatants from strain W10. These results suggest that B. amyloliquefaciens W10 has significant potential as a biocontrol agent.

  4. Does protein binding modulate the effect of angiotensin II receptor antagonists?

    Directory of Open Access Journals (Sweden)

    Marc P Maillard

    2001-03-01

    Full Text Available IntroductionAngiotensin II AT 1-receptor antagonists are highly bound to plasma proteins (≥ 99%. With some antagonists, such as DuP-532, the protein binding was such that no efficacy of the drug could be demonstrated clinically. Whether protein binding interferes with the efficacy of other antagonists is not known. We have therefore investigated in vitro how plasma proteins may affect the antagonistic effect of different AT1-receptor antagonists.MethodsA radio-receptor binding assay was used to analyse the interaction between proteins and the ability of various angiotensin II (Ang II antagonists to block AT1-receptors. In addition, the Biacore technology, a new technique which enables the real-time monitoring of binding events between two molecules, was used to evaluate the dissociation rate constants of five AT1-receptor antagonists from human serum albumin.ResultsThe in vitro AT 1-antagonistic effects of different Ang II receptor antagonists were differentially affected by the presence of human plasma, with rightward shifts of the IC50 ranging from one to several orders of magnitude. The importance of the shift correlates with the dissociation rate constants of these drugs from albumin. Our experiments also show that the way that AT1-receptor antagonists bind to proteins differs from one compound to another. These results suggest that the interaction with plasma proteins appears to modulate the efficacy of some Ang II antagonists.ConclusionAlthough the high binding level of Ang II receptor antagonist to plasma proteins appears to be a feature common to this class of compounds, the kinetics and characteristics of this binding is of great importance. With some antagonists, protein binding interferes markedly with their efficacy to block AT1-receptors.

  5. Role of opioid peptides in brain mechanisms regulating blood pressure.

    Science.gov (United States)

    de Jong, W; Petty, M A; Sitsen, J M

    1983-02-01

    Beta-endorphin and related opioid peptides are neuropeptides which appear to play a role in cardiovascular regulation which is supported by altered nociceptive responsiveness in hypertensive animals. In spontaneously hypertensive rats the pain threshold for electric stimulation is elevated; these rats show increased response latency time in a hot plate test. The opiate antagonist naloxone reverses these values to that of the normotensive controls. In other forms of experimental hypertension, eg, renal hypertension (one-clip, two-kidney model), no change in pain sensitivity is apparent. Sinoaortic baroreceptor denervation causes a labile hypertension without changes in hot plate response. Administration of beta-endorphin into the nucleus of the solitary tract (NTS) gradually decreases blood pressure and heart rate without affecting respiratory frequency. These cardiovascular effects are blocked by naloxone as well as by an antibody to beta-endorphin. In contrast to the effects of beta-endorphin, microinjection of enkephalins into the NTS increases blood pressure and heart rate. The data suggest the existence of two separate endorphin systems at the level of the NTS, one a depressor and another a pressor system. The depressor influence of beta-endorphin may play a role in the mechanism of action of antihypertensive agents such as methyldopa and clonidine. Our data support a role of endorphins as neuropeptides involved in cardiovascular regulation, exerting a dual influence at the level of the NTS.

  6. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney

    Directory of Open Access Journals (Sweden)

    N. L. Rukavina Mikusic

    2016-01-01

    Full Text Available Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP and Ang-(1-7 may regulate renal dopamine availability in tubular cells, contributing to Na+, K+-ATPase inhibition. Present results show that CNP did not affect either 3H-dopamine uptake in renal tissue or Na+, K+-ATPase activity; meanwhile, Ang-(1-7 was able to increase 3H-dopamine uptake and decreased Na+, K+-ATPase activity in renal cortex. Ang-(1-7 and dopamine together decreased further Na+, K+-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7 stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide did not modify CNP effects on 3H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7 on 3H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7 was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7 on AT1 receptors on 3H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7 enhances Na+, K+-ATPase activity inhibition, contributing to its natriuretic and diuretic effects.

  7. TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst

    Science.gov (United States)

    Hermann, Clemens; van Hateren, Andy; Trautwein, Nico; Neerincx, Andreas; Duriez, Patrick J; Stevanović, Stefan; Trowsdale, John; Deane, Janet E; Elliott, Tim; Boyle, Louise H

    2015-01-01

    Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system. DOI: http://dx.doi.org/10.7554/eLife.09617.001 PMID:26439010

  8. TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst.

    Science.gov (United States)

    Hermann, Clemens; van Hateren, Andy; Trautwein, Nico; Neerincx, Andreas; Duriez, Patrick J; Stevanović, Stefan; Trowsdale, John; Deane, Janet E; Elliott, Tim; Boyle, Louise H

    2015-10-06

    Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system.

  9. 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, ...

  10. Synthetic peptide vaccines: palmitoylation of peptide antigens by an thioester bond increases immunogenicity

    NARCIS (Netherlands)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.; Dalsgaard, K.; Langeveld, J.P.M.; Boshuizen, R.S.; Meloen, R.H.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many attempts

  11. Obviation of hydrogen fluoride in Boc chemistry solid phase peptide synthesis of peptide-αthioesters.

    Science.gov (United States)

    Gates, Zachary P; Dhayalan, Balamurugan; Kent, Stephen B H

    2016-11-29

    Under suitable conditions, trifluoromethanesulfonic acid performs comparably to hydrogen fluoride for the on-resin global deprotection of peptides prepared by Boc chemistry solid phase peptide synthesis (SPPS). Obviation of hydrogen fluoride in Boc chemistry SPPS enables the straightforward synthesis of peptide- α thioesters for use in native chemical ligation.

  12. Sexually antagonistic "zygotic drive" of the sex chromosomes.

    Directory of Open Access Journals (Sweden)

    William R Rice

    2008-12-01

    Full Text Available Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

  13. Central actions of a novel and selective dopamine antagonist

    International Nuclear Information System (INIS)

    Schulz, D.W.

    1985-01-01

    Receptors for the neurotransmitter dopamine traditionally have been divided into two subgroups: the D 1 class, which is linked to the stimulation of adenylate cyclase-activity, and the D 2 class which is not. There is much evidence suggesting that it is the D 2 class which is not. There is much evidence suggesting that it is the D 2 dopamine receptor that mediates the physiological and behavioral actions of dopamine in the intact animal. However, the benzazepine SCH23390 is a dopamine antagonist which has potent behavioral actions while displaying apparent neurochemical selectivity for the D 1 class of dopamine receptors. The purpose of this dissertation was to (1) confirm and characterize this selectivity, and (2) test certain hypothesis related to possible modes of action of SCH233390. The inhibition of adenylate cyclase by SCH23390 occurred via an action at the dopamine receptor only. A radiolabeled analog of SCH23390 displayed the receptor binding properties of a specific high-affinity ligand, and regional receptor densities were highly correlated with dopamine levels. The subcellular distribution of [ 3 H]-SCH23390 binding did not correspond completely with that of dopamine-stimulated adenylate cyclase. The neurochemical potency of SCH23390 as a D 1 receptor antagonist was preserved following parental administration. A variety of dopamine agonists and antagonists displayed a high correlation between their abilities to compete for [ 3 H]-SCH23390 binding in vitro and to act at an adenylate cyclase-linked receptor. Finally, the relative affinities of dopamine and SCH23390 for both D 1 receptors and [ 3 H]-SCH23390 binding sites were comparable. It is concluded that the behavioral effects of SCH23390 are mediated by actions at D 1 dopamine receptors only, and that the physiological importance of this class of receptors should be reevaluated

  14. Classification and virtual screening of androgen receptor antagonists.

    Science.gov (United States)

    Li, Jiazhong; Gramatica, Paola

    2010-05-24

    Computational tools, such as quantitative structure-activity relationship (QSAR), are highly useful as screening support for prioritization of substances of very high concern (SVHC). From the practical point of view, QSAR models should be effective to pick out more active rather than inactive compounds, expressed as sensitivity in classification works. This research investigates the classification of a big data set of endocrine-disrupting chemicals (EDCs)-androgen receptor (AR) antagonists, mainly aiming to improve the external sensitivity and to screen for potential AR binders. The kNN, lazy IB1, and ADTree methods and the consensus approach were used to build different models, which improve the sensitivity on external chemicals from 57.1% (literature) to 76.4%. Additionally, the models' predictive abilities were further validated on a blind collected data set (sensitivity: 85.7%). Then the proposed classifiers were used: (i) to distinguish a set of AR binders into antagonists and agonists; (ii) to screen a combined estrogen receptor binder database to find out possible chemicals that can bind to both AR and ER; and (iii) to virtually screen our in-house environmental chemical database. The in silico screening results suggest: (i) that some compounds can affect the normal endocrine system through a complex mechanism binding both to ER and AR; (ii) new EDCs, which are nonER binders, but can in silico bind to AR, are recognized; and (iii) about 20% of compounds in a big data set of environmental chemicals are predicted as new AR antagonists. The priority should be given to them to experimentally test the binding activities with AR.

  15. Atrial natriuretic peptides in plasma

    DEFF Research Database (Denmark)

    Goetze, Jens Peter; Hansen, Lasse H; Terzic, Dijana

    2014-01-01

    Measurement of cardiac natriuretic peptides in plasma has gained a diagnostic role in the assessment of heart failure. Plasma measurement is though hampered by the marked instability of the hormones, which has led to the development of analyses that target N-terminal fragments from the prohormone....... These fragments are stable in plasma and represent surrogate markers of the actual natriuretic hormone. Post-translational processing of the precursors, however, is revealing itself to be a complex event with new information still being reported on proteolysis, covalent modifications, and amino acid...

  16. Biodiscovery of Aluminum Binding Peptides

    Science.gov (United States)

    2013-08-01

    et al., "Biomimetic synthesis and patterning of silver nanoparticles," Nat. Mater. 1(3), 169-172 (2002). [5] Van Dorst, B., et al., "Phage display...Biotechnol. 68(4), 505-509 (2005). [10] Lee, Y. J., et al., "Fabricating genetically engineered high-power lithium-ion batteries using multiple virus genes...34Sequestration of zinc oxide by fimbrial designer chelators," Appl. Environ. Microbiol. 66(1), 10-14 (2000). [26] Hnilova, M., et al., "Peptide-directed co

  17. Membrane Formation in Liquids by Adding an Antagonistic Salt

    Directory of Open Access Journals (Sweden)

    Koichiro Sadakane

    2018-03-01

    Full Text Available Antagonistic salts are composed of hydrophilic and hydrophobic ions. In a binary mixture, such as water and organic solvent, these ion pairs preferentially dissolve to those phases, respectively, and there is a coupling between the charge density and the composition. The heterogeneous distribution of ions forms a large electric double layer at the interface between these solvents. This reduces the interfacial tension between water and organic solvent, and stabilizes an ordered structure, such as a membrane. These phenomena have been extensively studied from both theoretical and experimental point of view. In addition, the numerical simulations can reproduce such ordered structures.

  18. Synthesis of carbon-11 labelled calcium channel antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Holschbach, M.; Roden, W.; Hamkens, W. (Kernforschungsanlage Juelich GmbH (Germany). Inst. fuer Medizin)

    1991-04-01

    A useful synthetic approach to carbon-11 labelled 1,4-dihydropyridines is described. Carbon-11 labelled calcium channel antagonists {sup 11}C-Nifedipine, {sup 11}C-Nisoldipine, {sup 11}C-nitrendipine and {sup 11}C-CF{sub 3}-Nifedipine were synthesized by a modified Hantzsch method using protected carboxy functions. Deprotection of the carboxylic acids by alkaline hydrolysis followed by conversion into the corresponding potassium salts and subsequent methylation with {sup 11}CH{sub 3}I produced the labelled compounds in very good chemical and radiochemical yields (94%). (author).

  19. The opiate antagonist, naltrexone, in the treatment of trichotillomania

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Schreiber, Liana R N

    2014-01-01

    Trichotillomania (TTM) is characterized by repetitive hair pulling resulting in hair loss. Data on the pharmacological treatment of TTM are limited. This study examined the opioid antagonist, naltrexone, in adults with TTM who had urges to pull their hair. Fifty-one individuals with TTM were...... randomized to naltrexone or placebo in an 8-week, double-blind trial. Subjects were assessed with measures of TTM severity and selected cognitive tasks. Naltrexone failed to demonstrate significantly greater reductions in hair pulling compared to placebo. Cognitive flexibility, however, significantly...

  20. Pharmacoepidemiological assessment of drug interactions with vitamin K antagonists

    DEFF Research Database (Denmark)

    Pottegård, Anton; Christensen, R. D.; Wang, S. V.

    2014-01-01

    PurposeWe present a database of prescription drugs and international normalized ratio (INR) data and the applied methodology for its use to assess drug-drug interactions with vitamin K antagonists (VKAs). We use the putative interaction between VKAs and tramadol as a case study. MethodsWe used...... definitions, and other drugs. ResultsWe identified 513 VKA users with at least 1 INR measurement 4.0 and concomitant tramadol and VKA exposure during the observation period. The overall IRR was 1.80 (95% confidence interval [CI], 1.53-2.10), with a stronger association among users of phenprocoumon compared...