摘要:

AbstractReported is the preparation of wheat germ (WG) hydrolyzate with potent angiotensin I‐converting enzyme (ACE) inhibitory activity, and the characterization of peptides responsible for ACE inhibition. Successful hydrolyzate with the most potent ACE inhibitory activity was obtained by 0.5 wt.%–8 hBacillus licheniformisalkaline protease hydrolysis after 3.0 wt.%–3 h α‐amylase treatment of defatted WG (IC50; 0.37 mg protein ml−1). The activity of WG hydrolyzate was markedly increased by ODS and subsequent AG50W purifications (IC50; 0.018 mg protein ml−1). As a result of isolations by high performance liquid chromatographies, 16 peptides with the IC50value of less than 20 μm, composed of 2–7 amino acid residues were identified from the WG hydrolyzate. Judging from the high content (260 mg in 100 g of AG50W fraction) and powerful ACE inhibitory activity (IC50; 0.48 μm), Ile‐Val‐Tyr was identified as a main contributor to the ACE inhibition of the hydrolyzate. Copyright © 1999 European Peptide Society and

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<289::AID-PSC196>3.0.CO;2-6

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractIt was previously found that a cationic amphiphilic peptide, Ac‐(Leu‐Ala‐Arg‐Leu)3‐NHCH3(43), caused the destabilization of a phospholipid membrane and showed strong antibacterial activity [Leeet al.Biochim. Biophys. Acta1986;862: 211–219]. In order to investigate the effect of changing α‐helix propensity, hydrophobicity and basicity in43on the peptide conformation and activity, the43analogs, [Gly (or Val)6]43, [Gly (or Val)2,6]43, [Gly (or Val)2,6,10]43, [Gln3]43, [Gln3,7]43and [Gln3,7,11]43were synthesized. Except for [Val2,6]43and [Val2,6,10]43, which mainly formed a β‐structure, other peptides formed an α‐helix and showed moderate membrane‐perturbing activity toward neutral and acidic lipid vesicles. All the peptides other than [Val2,6,10]43and [Gln3,7,10]43had the antibacterial activity comparable with that of43. The relationship between the membrane‐perturbing activity and the antibacterial activity was not always parallel. Conclusively, the Ala→Val substitution in43causes the change of peptide conformation and the presence of a cationic amino acid residue is necessary for the antibacterial activity. Copyright © 1999 European Peptide Socie

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<298::AID-PSC197>3.0.CO;2-5

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractDynorphin A, the endogenous agonist for the κ opioid receptor, has been studied by NMR spectroscopy in methanol, acetonitrile, DMSO and in mixtures of hexafluoroacetone/water and DMSO/water. NMR data in the DMSO/water cryomixture at 278 K are consistent with a conformer in which theN‐terminal part, like the corresponding message domain of enkephalins, is poorly ordered, whereas theC‐terminal part is folded in a loop centred around Pro10. The folded structure of theC‐terminal part (address moiety) may shed light on the role of the essential residues Arg7, Lys11and Lys13. Copyright © 1999 European Peptide Society and John Wiley&So

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<306::AID-PSC199>3.0.CO;2-B

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractThe design and synthesis of cyclic mimetics of VCAM‐1 protein that reproduce the integrin‐binding domain are presented. The unprotected peptide precursor37–43, Thr‐Gln‐Ile‐Asp‐Ser‐Pro‐Leu, was grafted onto functional templates of type naphthalene, biphenyl and benzyl through the chemoselective formation ofC‐ andN‐terminal oximes resulting in a mixture of four isomeric forms due tosyn–antiisomerism of the oxime bonds. Some isomers could be monitored by HPLC and identified by NMR. The molecule containing a naphthalene‐derived template was found to inhibit the VCAM‐1/VLA‐4 interaction more efficiently than previously reported for sulfur‐bridged cyclic peptides containing similar sequences. The finding confirms the importance of incorporating conformational constraints between the terminal ends of the peptide loop37–43in the design of synthetic inhibitors of the VCAM‐1/integrin interaction. Copyright © 1999 European Pept

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<313::AID-PSC200>3.0.CO;2-F

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractCoagulation factor VII bound to its cofactor tissue factor is the physiological initiator of blood coagulation. The interaction between factor VII and tissue factor involves all four of the structural modules found in factor VII, with the most significant contribution coming from the first EGF‐like domain. In this study, the synthesis and biological activity of several analogues derived from the first EGF‐like domain of FVII comprising the sequence 45–83 are reported on. The six cysteine residues found in the native protein were replaced by Abu. The peptides were isolated from a multicomponent mixture following standard Fmoc solid phase synthesis. Purification and characterisation of the heterogeneous product showed that aspartimide formation was a major side‐reaction, occurring predominantly at the Asp46‐Gly47and Asn57‐Gly58dipeptides. Although relatively common in peptide synthesis, the extent to which this side‐reaction had taken place was considered surprising. Reported herein are the analytical methods used to isolate and characterise several of the modified products. Also, the inhibitory effect of these peptides on the formation and enzymatic activity of the factor VIIa/tissue factor complex have been compared. Surprisingly, the peptide containing aniso‐Asp residue at position 57 possessed 66‐fold higher inhibitory activity compared with the original target peptide. A possible explanation for this increase in observed activity is presented. Copyright © 1999 European Peptide Society and Jo

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<323::AID-PSC201>3.0.CO;2-B

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractTheN‐terminal 1–34 segments of both parathyroid hormone (PTH) and parathyroid hormone‐related protein (PTHrP) bind and activate the same membrane receptor in spite of major differences in their amino acid sequence. The hypothesis was made that they share the same bioactive conformation when bound to the receptor. A common structural motif in all bioactive fragments of the hormone in water/trifluoroethanol mixtures or in aqueous solution containing detergent micelles is the presence of two helical segments at theN‐ andC‐termini of the sequence. In order to stabilize the helical structures, we have recently synthesized and studied the PTHrP(1–34) analog [(Lys13–Asp17, Lys26–Asp30)]PTHrP(1–34)NH2, which contains lactam‐constrained Lys‐Asp side chains at positionsi,i+4. This very potent agonist exhibits enhanced helix stability with respect to the corresponding linear peptide and also two flexible sites at positions 12 and 19 in 1:1 trifluoroethanol/water. These structural elements have been suggested to play a critical role in bioactivity. In the present work we have extended our conformational studies on the bicyclic lactam‐constrained analog to aqueous solution. By CD, 2D‐NMR and structure calculations we have shown that in water two helical segments are present in the region of the lactam bridges (13–18, and 26–31) with high flexibility around Gly12and Arg19. Thus, the essential structural features observed in the aqueous‐organic medium are maintained in water even if, in this solvent, the overall structure is more flexible. Our findings confirm the stabilizing effect of side‐chain lactam constraints on the α‐helical structure. Copyright © 1999 European Pep

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199907)5:7<330::AID-PSC205>3.0.CO;2-7

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY