摘要:

AbstractA commentary on the confusing nomenclature and bibliography of serial publications which use the term ‘peptide’ in their titles is given, with guidance on citation. Copyright © 2006 European Peptide Society and John Wiley&Sons,

ISSN:1075-2617    

DOI:10.1002/psc.772

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractNeurotensin(8‐13) analogs containing a glycine or 5‐aminovaleroyl spacer were labeled with fluorescein through formation of anN‐terminal thiourea function. The receptor binding was measured in HT‐29 cell cultures and showed a substantial decrease in affinity, especially for the metabolically stabilized [MeArg9, Tle11] analog. Using fluorescence microscopy, the internalization of the fluorescent neurotensin analogs into HT‐29 cells was observed. Copyright © 2006 European Peptide Society and John Wiley

ISSN:1075-2617    

DOI:10.1002/psc.757

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractMung bean protein isolates were hydrolyzed for 2 h by Alcalase. The generated hydrolysate showed angiotensin I‐converting enzyme (ACE) inhibitory activity with the IC50value of 0.64 mg protein/ml. Three kinds of novel ACE inhibitory peptides were isolated from the hydrolysate by Sephadex G‐15 and reverse‐phase high performance liquid chromatography (RP‐HPLC). These peptides were identified by amino acid composition analysis and matrix assisted‐laser desorption/ionization time‐of‐flight tandem mass spectrometry (MALDI‐TOF MS/MS), as Lys‐Asp‐Tyr‐Arg‐Leu, Val‐Thr‐Pro‐Ala‐Leu‐Arg and Lys‐Leu‐Pro‐Ala‐Gly‐Thr‐Leu‐Phe with the IC50values of 26.5 µM, 82.4 µMand 13.4 µM, respectively. Copyright © 200

ISSN:1075-2617    

DOI:10.1002/psc.758

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractBrain‐derived neurotrophic factor (BDNF) is a protein that promotes the survival of neurons. It is widely thought to possess clinical potential for the treatment of neurodegenerative diseases, and in recent years, has been found to play a role in the pathogenesis of some tumours. BDNF is thought to bind to its cellular receptors trkB and p75NTRprimarily by way of solvent‐exposed loops on the BDNF dimer. In this paper, we describe our recent progress towards the development of small peptides as mimetics and inhibitors of BDNF. Two classes of peptides were prepared: disulphide‐constrained monomeric monocyclic peptides designed to mimic a single solvent‐exposed loop; and homo‐ and heterodimeric bicyclic peptides designed to mimic pairs of loops. Each peptide was examined in cultures of embryonic chick dorsal root ganglion sensory neurons, both alone, and in competition with BDNF. All peptides were found to inhibit BDNF‐mediated neuronal survival, while one—a dimeric peptide based on the two loop 4 regions of BDNF—behaved as a partial BDNF‐like agonist. The work described in this paper supports the proposed receptor‐binding role of loops 1, 2, and 4 of BDNF, and provides valuable steps towards our long‐term goal of developing BDNF mimetics and inhibitors for clinical use. Copyright © 2006 European Peptide Society an

ISSN:1075-2617    

DOI:10.1002/psc.760

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractMethodology is described here for the efficient parallel synthesis and cyclization of linear peptide libraries using intramolecularS‐alkylation chemistry in combination with Multipin™solid phase peptide synthesis (Multipin™SPPS). The effective use of this methodology was demonstrated with the synthesis of a 72‐member combinatorial library of cyclic thioether peptide derivatives of the conserved four‐residue structural motifDD/EXKfound in the active sites of the five crystallographically defined orthodox type II restriction endonucleases,EcoRV,EcoRI,PvuII,BamHI andBglI. Copyright © 2006 European Peptide Society and John Wiley

ISSN:1075-2617    

DOI:10.1002/psc.761

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractTemporin A (TA) is a hydrophobic peptide isolated from the skin of the European red frogRana temporaria.Strong antimicrobial activity against gram‐positive cocci and Candida, as well as its small molecular weight (10–13 aa residues), makes TA an interesting antimicrobial compound. However, its synthesis is rather problematic. Here, the synthesis of two retro‐analogues of TA – retro‐TA and (6‐1)(7‐13)‐TA—is reported. The synthesis of retro‐TA was performed without any problems, while during the synthesis of (6–1)(7–13)‐TA problems similar to those encountered during the synthesis of TA were faced. Antimicrobial assays showed minimal inhibitory concentration (MIC) values of retro‐TA to be, in most cases, only one dilution higher than those of original TA, but still remained relatively low. An analysis of the circular dichroism spectra of the peptides shows that TA and (6‐1)(7‐13)‐TA adopt an α‐helical structure in a hydrophobic environment, while retro‐TA forms mainly unordered conformation under both hydrophobic and hydrophilic conditions. One can postulate that differences in conformation of the peptide chain might be responsible for the lower antimicrobial activity of retro‐TA as compared to that of the parent molecule. In any case, retro‐TA can be interesting owing to its simple and nonproblematic synthesis. Copyright © 2006 Europe

ISSN:1075-2617    

DOI:10.1002/psc.762

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractThe crystal structures of two diastereomeric α,β‐dehydrobutyrine peptides Ac‐Pro‐(Z)‐ΔAbu‐NHMe (I) and Ac‐Pro‐(E)‐ΔAbu‐NHMe (II) have been determined. Both dehydropeptides adopt βI‐turn conformation characterized by the pairs of (ϕi+1, ψi+1) and (ϕi+2, ψi+2) angles as −66, −19, −97, 11° for I and −59, −27, −119, 29° for II. In each peptide, the βI turn is stabilized by (i+ 3) →iintramolecular hydrogen bonds with N·O distance of 3.12 Å for I and 2.93 Å for II. These structures have been compared to the crystal structures of homologous peptides Ac‐Pro‐ΔVal‐NHMe and Ac‐Pro‐ΔAla‐NHMe. Theoretical analyses by DFT/B3LYP/6–31 + G** method of conformers formed by these four peptides and by the saturated peptide Ac‐Pro‐Ala‐NHMe revealed that peptides with a (Z) substituent at the Cβi+2atom of dehydroamino acid, i.e. Ac‐Pro‐ΔVal‐NHMe and Ac‐Pro‐(Z)‐ΔAbu‐NHMe, predominantly form β turns, bothin vacuoand in polar environment. The tendency to adopt β‐turn conformation is much weaker for the peptides lacking the (Z) substituent, Ac‐Pro‐(E)‐ΔAbu‐NHMe and Ac‐Pro‐ΔAla‐NHMe. The latter adopts a semi‐extended or an extended conformation in every polar environment, including a weakly polar solvent. The saturated peptide Ac‐Pro‐Ala‐NHMein vacuoprefers a β‐turn conformation, but in polar environment the differences between various conformers are small. The role of π‐electron correlation and intramolecular hydrogen bonds interactio

ISSN:1075-2617    

DOI:10.1002/psc.763

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractThe Id proteins are negative regulators of several basic‐helix‐loop‐helix (HLH) transcription factors, including the ubiquitous E factors and the tissue‐specific myogenin‐regulating factors. Id1 through Id4 contain highly identical HLH domains but differentN‐ andC‐terminal extensions. Beside the heterodimerization with the parent HLH factors, Id2 was shown to additionally interact with the retinoblastoma protein and to be overexpressed in neuroblastoma. Thus, Id2 represents an interesting target for cancer therapy based on the inhibition of protein–protein interactions. Here we present the synthesis and circular dichroism (CD) analysis of peptides derived from point mutations andN‐/C‐terminal truncations of Id2. The helix character of the HLH domain (residues 36–76) was reduced upon substitution of Met39/‐62 and Cys42 with Nle and Ser, respectively, suggesting a structural role of these side chains. The largest sequence that could be obtained by stepwise solid‐phase peptide synthesis (SPPS) with Fmoc strategy spanned the entire HLH motif (with Cys42 replaced by Ser) and part of theC‐terminus (residues 77–110). This 75‐residue long fragment was less helical than the isolated HLH domain and had propensity to aggregate, which was correlated with the presence of the flanking residuesC‐terminal to helix‐2. By CD analysis of an equimolar mixture of the sequence 36–110 with theN‐terminus 1–35, noncovalent interactions between the two peptides were detected, which, however, changed upon aging. In contrast, the mixture of the HLH sequence 36–76 with theN‐terminus was characterized by a stabilized helix structure that was maintained also upon aging. Presumably, theN‐terminal region interacted with the folded HLH motif in a specific manner, whereas only unspecific, weak contacts occurred with the partly unfolded HLH domain and/or the immediate flanking residues 77–110. Copyright © 2006

ISSN:1075-2617    

DOI:10.1002/psc.764

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY

摘要:

AbstractTwo new cyclic oligomers, cyclo‐tetra‐[2,4‐anhydro‐3‐O‐tert‐butyldimethylsilyl‐5‐deoxy‐L‐rhamnonamido‐(N→5)] and the corresponding 6‐deoxy‐D‐gulonate cyclic ‘tetramer’, have been synthesised from linear tetrameric oligomers, using TBTU‐ and pentafluorophenyl ester–based methodologies, respectively. These two compounds constitute a novel class of cyclic oligomers derived from oxetane‐based sugar amino acids. Copyright © 2006 Europea

ISSN:1075-2617    

DOI:10.1002/psc.759

出版商:John Wiley&Sons, Ltd.    

年代:2006

数据来源: WILEY