ISSN:1075-2617    

DOI:10.1002/psc.1000

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractGlycopeptide dendrimers are branched structures containing both carbohydrates and peptides. Various classes of these compounds differing in composition and structure are mentioned, together with their practical use spanning from catalysis, transport vehicles to synthetic vaccines. The main stress is given to glycopeptide dendrimers, namely multiple antigen glycopeptides (MAGs). In MAGs, the core, branches or both are composed of amino acids or peptides. Other classes of glycodendrimers (PAMAM, polypropylene imine, cyclodextrin, calixarene, etc.) are mentioned too, but to a smaller extent. Their syntheses, physicochemical properties and biological activities are given with many examples. Glycopeptide dendrimers can be used as inhibitors of cell surface protein‐carbohydrate interactions, intervention with bacterial adhesion, for studying of recognition processes, diagnostics, imaging and contrast agents, mimetics, for complexation of different cationts, as site‐specific molecular delivery systems, for therapeutic purposes, as immunodiagnostics and in drug design. Biomedical applications of glycopeptide dendrimers as drug and gene delivery systems are also given. Copyright © 2007 European Peptide Society and John Wiley&Sons,

ISSN:1075-2617    

DOI:10.1002/psc.931

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractGlycopeptide dendrimers are regularly branched structures containing both carbohydrates and peptides. Various types of these compounds differing in composition and structure are mentioned, together with their practical use spanning from catalysis, transport vehicles to synthetic vaccines. This Part II (for Part I see Ježek J,et al., J. Pept. Sci. 2008;14: 2–43) covers linear oligomers with variable valency (brush dendrimers, comb dendrimers), sequential oligopeptide carriers SOCn‐I and SOCn‐II, chitosan‐based dendrimers, and brush dendrimers. Other types of glycopeptide dendrimers are self‐immolative dendrimers (cascade release dendrimers, domino dendrimers), dendrimers containing ω‐amino acids (Gly, β‐Ala, γ‐Abu and ε‐aminohexanoic acid), etc. Microwave‐assisted synthesis of dendrimers and libraries of glycopeptides and glycopeptide dendrimers are also included. Characterization of dendrimers by electromigration methods, mass spectrometry, and time‐resolved and nonlinear optical spectroscopy, etc. plays an important role in purity assessment and structure characterization. Physicochemical properties of dendrimers including chirality are given. Stability of dendrimers, their biocompatibility and toxicity are reviewed. Finally, biomedical applications of dendrimers including imaging agents (contrast agents), site‐specific drug delivery systems, artificial viruses, synthetic antibacterial, antiviral, and anticancer vaccines, inhibitors of cell surface protein–carbohydrate interactions, intervention with bacterial adhesion, etc. are given. Glycopeptide dendrimers were used also for studying recognition processes, as diagnostics and mimetics, for complexation of different cations, for therapeutic purposes, as immunodiagnostics, and in drug design. Copyright © 2007 European Peptide S

ISSN:1075-2617    

DOI:10.1002/psc.945

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractWe investigated the spectroscopic properties of the aromatic residues in a set of octapeptides with various self‐assembly properties. These octapeptides are based on lanreotide, a cyclic peptide analogue of somatostatin‐14 that spontaneously self‐assembles into very long and monodisperse hollow nanotubes. A previous study on these lanreotide‐based derivatives has shown that the disulfide bridge, the peptide hairpin conformation and the aromatic residues are involved in the self‐assembly process and that modification of these properties either decreases the self‐assembly propensity or modifies the molecular packing resulting in different self‐assembled architectures. In this study we probed the local environment of the aromatic residues, naphthyl‐alanine, tryptophan and tyrosine, by Raman and fluorescence spectroscopy, comparing nonassembled peptides at low concentrations with the self‐assembled ones at high concentrations. As expected, the spectroscopic characteristics of the aromatic residues were found to be sensitive to the peptide–peptide interactions. Among the most remarkable features we could record a very unusual Raman spectrum for the tyrosine of lanreotide in relation to its propensity to form H‐bonds within the assemblies. In Lanreotide nanotubes, and also in the supramolecular architectures formed by its derivatives, the tryptophan side chain is water‐exposed. Finally, the low fluorescence polarization of the peptide aggregates suggests that fluorescence energy transfer occurs within the nanotubes. Copyright © 2007 European Peptide Society

ISSN:1075-2617    

DOI:10.1002/psc.913

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractArginine vasopressin (AVP) and mesotocin (MT) belong to the neurohypophyseal hormone family. The former plays a very important role in the control of urine concentration and the blood pressure in mammals, whereas the latter stimulates uterine concentration and initiates birth in amphibians, marsupials, wallabies, birds, and fishes. Analysis of their 3D structure could be helpful for understanding the evolutionary relationship between all vasopressin‐ and oxytocin‐like hormones. In addition, it allows design of new analogs with appropriate biological activity for humans and animals. In this paper, we present the conformational studies of AVP and MT, under the aqueous conditions. In our investigations, we used 2D NMR spectroscopy and time‐averaged molecular dynamics calculations in explicit water. Our studies have shown that both peptides, despite displaying a high sequence homology, differ from each other with regard to the three‐dimensional structure. They are in conformational equilibrium as a result of thecis/transisomerization across the Cys6–Pro7peptide bond. Both peptides form β‐turns in their cyclic part, wherein theC‐terminal fragment of MT is bent, whereas that of AVP is extended. Copyright © 2007 European Peptide Society and John

ISSN:1075-2617    

DOI:10.1002/psc.918

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractThere is much evidence to support the hypothesis that lipids play a role in the interaction of peptide hormones with their membrane receptors. This interaction through change of peptide conformation can facilitate the entry of the hormone into the microenvironment of the receptor. In the present study we have examined the interaction of vasopressin and mesotocin with a lipid—sodium dodecylsulfate (SDS) micelle—using 2D nuclear magnetic resonance (NMR) and theoretical methods. Solution structures of two hormones in solution with SDS were established using the nuclear Overhauser effect (NOE) and the3JNHHαcouplings. The amino acid sequences of these peptides are: c[C1‐Y2‐F3‐Q4‐N5‐C6]‐P7‐R8‐G9‐NH2([Arg8]vasopressin, AVP) and c[C1‐Y2‐I3‐Q4‐N5‐C6]‐P7‐I8‐G9‐NH2(MT). Each of the peptides was found to occur as one stable conformation. AVP adopts thecisconfiguration on the Cys1‐Tyr2peptide bond, a finding not reported so far. The three‐dimensional structures of the two peptides studied were determined by a method that consisted of time‐averaged molecular dynamics inan explicitSDS micelle with the parm99 force field in AMBER8.0 package. All calculated structures of the studied peptides form β‐turns in their cyclic parts. TheC‐terminal fragment of MT is bent, whereas that of AVP is extended. Copyright © 20

ISSN:1075-2617    

DOI:10.1002/psc.917

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

Abstract1H‐Benzotriazolium 1‐[bis(dimethyl‐amino)methylene]‐5‐chloro‐hexafluorophosphate (1‐),3‐oxide (HCTU) is a nontoxic, nonirritating and noncorrosive coupling reagent. Seven biologically active peptides (GHRP‐6,65–74ACP, oxytocin, G‐LHRH,C‐peptide, hAmylin1–37, and β‐amyloid1–42) were synthesized with reaction times reduced to deprotection times of 3 min or less and coupling times of 5 min or less using HCTU as the coupling reagent. Expensive coupling reagents or special techniques were not used. Total peptide synthesis times were dramatically reduced by as much as 42.5 h (1.8 days) without reducing the crude peptide purities. It was shown that HCTU can be used as an affordable, efficient coupling reagent for fast Fmoc solid‐phase peptide synthesis. Copyright © 2007 European Peptide

ISSN:1075-2617    

DOI:10.1002/psc.921

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractIncrease of VPAC receptor s binding to the16γ‐glutamyl diaminopropane vasoactive intestinal peptide (VIP‐DAP) agonist, a vasoactive intestinal polypeptide (VIP) structural analogue containing a positive charge at position 16, has confirmed the importance of a positive charge at this site. By investigating the effect of distance from the peptide backbone Cα of a positive charge in position 16, data are reported here concerning: (i) a novel chemical method used for the synthesis of a new family of16γ‐glutamyl diamine VIP derivatives differing among them for single carbon atoms and including diaminoethane (VIP‐DAE2), diaminopropane (VIP‐DAP3), diaminobutane (VIP‐DAB4), diaminopentane (VIP‐DAP5), and diaminohexane (VIP‐DAH6); (ii) functional characterization of these compounds on human VPAC1 and VPAC2 receptors. In more detail, the EC50 and IC50 values, when measured as a function of the alkylic chain length, show in more detail, that the use of VIP‐DAB4 derivative changes the IC50 but not the EC50, thus indicating on hVPAC2 receptor an unexpected relationship between binding and activity that differs from that obtained on hVPAC1. Copyright © 2007 European Peptide Society and

ISSN:1075-2617    

DOI:10.1002/psc.925

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

摘要:

AbstractThe drastic increase in multi‐drug‐resistant bacteria has created an urgent need for new therapeutic interventions, including antimicrobial peptides, an interesting template for novel drug development. However, the process of optimizing peptide antimicrobial activity and specificity using large peptide libraries is both tedious and expensive. Here we confirm the use of a mathematical model for prediction, prior to synthesis, of peptide antibacterial activity toward the antibiotic resistant pathogenPseudomonas aeruginosa. By the use of novel descriptors quantifying the contact energy between neighboring amino acids, as well as a set of inductive and conventional QSAR descriptors, we were able to model the antibacterial activity of peptides. Cross‐correlation and optimization of the implemented descriptor values enabled us to build two models, using very limited sets of peptides, which were able to correctly predict the activity of 85 or 71% of the tested peptides, within a twofold deviation window of the corresponding previously assessed IC50values, measured earlier. Though these two models were significantly different in size, they demonstrated no significant difference in their predictive power, implying that it is possible to build powerful predictive models using even small sets of structurally different peptides, when using contact‐energy descriptors and inductive and conventional QSAR descriptors in the model design. Copyright © 2007 European Peptide Society and John Wiley&S

ISSN:1075-2617    

DOI:10.1002/psc.908

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY

ISSN:1075-2617    

DOI:10.1002/psc.986

出版商:John Wiley&Sons, Ltd.    

年代:2008

数据来源: WILEY