ISSN:1075-2617    

DOI:10.1002/psc.927

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractThe current article reports on the synthesis of a new type of cyclic peptidosteroid, in which a bile‐acid‐based scaffold was used for the conformational restriction of a loop‐like peptide. Convergent coupling of two tetrapeptides to the non‐peptidic steroidal entity was carried out once in the classical C‐to‐N and once in the non‐classical N‐to‐C direction. Peptide backbone cyclisation was then carried out, giving rise to a ring size equivalent to approximately 12 amino acids. This type of construct will be used in the development of a peptide vaccine against measles. Copyright © 2007 European Peptide Society and Jo

ISSN:1075-2617    

DOI:10.1002/psc.868

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractThis report reviews our approach to the design, synthesis and structural/morphological analysis of backbone‐modified amylin(20–29) derivatives. Depending on the position in the peptide backbone and the type of amide bond isostere/modification, the amylin(20–29) peptides behave either as inhibitors of amyloid fibril formation, which are able to retard amyloid formation of native amylin(20–29), or as templates for the formation of self‐assembled supramolecular structures. Molecular fine‐tuning of the hydrogen‐bond accepting/donating properties allows the control over the morphology of the supramolecular aggregation motifs such as helical ribbons and tapes, ribbons progressing to closed peptide nanotubes, (twisted) lamellar sheets or amyloid fibrils. Copyright © 2007 European Peptide Society and John W

ISSN:1075-2617    

DOI:10.1002/psc.831

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractFmoc‐protected β3hserine (β3hSer) was prepared andO‐linked to suitably protectedN‐acetylgalactosamine (GalNAc) andN‐acetylglucosamine (GlcNAc) derivatives. Glycosylation of β3hSer was made by two independent routes: either by direct glycosyl linkage to the β3hSer, or linkage to naturalL‐Ser and then utilizing the carbohydrate moiety as a protecting group in an Arndt–Eistert homologation. Both procedures gave the novel glycosylated β3‐amino acids Fmoc‐β3hSer(α‐D‐GalNAc(Ac)3)‐OH (1a), its β‐anomer (1b), and Fmoc‐β3hSer(β‐D‐GlcNAc(Ac)3)‐OH (2), which were utilized in the solid‐phase peptide synthesis of four glycosylated dipeptides (3a–d) and two heptapeptides (4a–b). The preparation of β‐amino acids bearing common post‐translational modifiers represents an important step towards functionalized foldamers with broad applications in biomedical research. Copyright © 2

ISSN:1075-2617    

DOI:10.1002/psc.832

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractThe present work is a combined structural study, using Nuclear Magnetic Resonance (NMR) and Molecular Dynamics(MD), of the amidated and the free acid forms of substance P in water and methanol. The results obtained using both approaches were compared in order to characterize the structural features of both peptides in solution. From the NMR experiments it was derived that the free acid form adopts an extended conformation at theN‐terminus and a helical conformation at theC‐terminal segment of the peptide in both water and methanol; these structural features are in qualitative agreement with the results of the MD simulations. No significant differences in behavior were observed between the amidated and the free acid forms of the peptide in the simulations and in the experiments carried out in water, suggesting that the different activities of these analogs are due to their different mode of interaction with the receptor rather than to their structural preferences. Finally, we propose that the structure of substance P can be partially inferred from its sequence due to the presence of a Pro‐X‐Pro motif on theN‐terminus and a Gly–Leu sequence on theC‐terminus. Copyright © 2007 European Peptide Society and John W

ISSN:1075-2617    

DOI:10.1002/psc.880

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractThe Fmoc‐based SPPS of H‐Xaa‐Asp(OBzl)‐Yaa‐Gly‐NH2sequences results in side reactions yielding not only aspartimide peptides and piperidide derivatives, but also 1,4‐diazepine‐2,5‐dione‐peptides. Evidence is presented to show that the 1,4‐diazepine‐2,5‐dione derivative is formed from the aspartimide peptide. The rate of this ring transformation depends primarily on the tendency to aspartimide and piperidide formation, which is influenced by the nature of the amino acid following the aspartic acid β‐benzyl ester (Xaa). However the bulkiness of the amino acid side chain preceeding the aspartic acid β‐benzyl ester (Yaa) is also important. Under certain conditions the 1,4‐diazepine‐2,5‐dione peptide derivative may even be formed dominantly, which is a highly undesirable side reaction in peptide synthesis, but which provides a new way for the synthesis of diazepine peptide derivatives with targeted biological or pharmacological activity. Copyright © 2007 European Pe

ISSN:1075-2617    

DOI:10.1002/psc.885

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractA small peptide library of monocyclic SFTI‐1 trypsin inhibitor from sunflower seeds modified in positions P1and P4′ was synthesized using a portioning‐mixing method. The peptide library was deconvoluted by the iterative approach in solution. Two trypsin ([Met9]‐SFTI‐1 and [Arg5, Abu9]‐SFTI‐1), one chymotrypsin ([Phe5]‐SFTI‐1) and one human elastase ([Leu5, Trp9]‐SFTI‐1) inhibitors were selected and resynthesized. The values of their association equilibrium constants (Ka) with target enzymes indicate that they are potent inhibitors. In addition, the last two analoges belong to the most active inhibitors of this size. The results obtained show that the conserved Pro9residue in the Bowman–Birk inhibitor (BBI)s is not essential for inhibitory activity. Copyright © 2007 European Peptide Society

ISSN:1075-2617    

DOI:10.1002/psc.887

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractIodination of the conserved 2‐tyrosine (Tyr2) residue in the pressin and tocin rings of arginine‐ or lysine‐vasopressin (AVP or LVP), and oxytocin, respectively, impairs binding to their respective receptors. Synthetic antagonists that have their Tyr2either replaced by another amino acid or irreversibly blocked by anO‐methyl orO‐ethyl ether, but have, instead, an iodinatable phenol moiety outside the pressin/tocin ring, are used for radiolabeling. We explored another approach to avoid iodinating Tyr2by capping this residue with a reversibleO‐acetyl group, incorporated during peptide synthesis. TheO‐acetyl‐Tyr2LVP peptide, with a free iodinatable tyrosine attached to the ε‐amine of 8‐lysine, is iodinated at a neutral pH and purified by reverse‐phase high‐pressure liquid chromatography (HPLC) at an acidic pH, conditions under which theO‐acetyl groups are stable. Deacetylation with hydroxylamine is selective, and leaves intact the disulfide bridge. The marked shortening of the HPLC retention time after deblocking produces a chemically homogeneous label, iodinated exclusively on the free tyrosine residue attached to the ε‐amine of LVP. Hitherto, this125I labeled vasopressin agonist could be obtained only in low yield, via conjugation labeling with iodinatedN‐t‐Boc‐tyrosine succinimidyl ester. This fully reversible tyrosine protection strategy does not require special equipment, and retains the conserved Tyr2, typical of vasopressin and oxytocin agonists. Copyright © 2007 European Pept

ISSN:1075-2617    

DOI:10.1002/psc.890

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractAn antifungal peptide with a molecular mass of approximately 4 kDa was isolated from buckwheat seeds by using ion‐exchange chromatography on SP‐Sepharose and Q‐Sepharose, and gel filtration on Superdex peptide. The peptide was adsorbed on SP‐Sepharose in 10 mMNH4OAc buffer (pH 4.5) and on Q‐Sepharose in 10 mMNH4HCO3buffer (pH 9.4), and appeared to be highly purified after these two steps. It inhibited mycelial growth inFusarium oxysporumandMycosphaerella arachidicolawith an IC50of 35 and 40 µM, respectively. Its antifungal activity was stable between 0 and 70 °C, and between pH 1.0/2.0 and 13. It inhibited proliferation of Hep G2 (hepatoma) cells, L1210 (leukemia) cells, breast cancer (MCF‐7) cells, and liver embryonic WRL 68 cells with an IC50of 33, 4, 25, and 37 µM, respectively. On the other hand, the peptide was unable to evoke a mitogenic response from splenocytes or induce nitric oxide production by macrophages. It inhibited HIV‐1 reverse transcriptase with an IC50of 5.5 µM. Copyright © 2007 European Peptide Society and Jo

ISSN:1075-2617    

DOI:10.1002/psc.891

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY

摘要:

AbstractThe original article to which this Erratum refers was published in Journal of Peptide Science, 2007; 13: 363–36

ISSN:1075-2617    

DOI:10.1002/psc.920

出版商:John Wiley&Sons, Ltd.    

年代:2007

数据来源: WILEY