摘要:

AbstractA cyclic somatostatin analog (1) has been synthesized. Biological assays show that this compound has strong binding affinities to somatostatin hsst2 and hsst5 receptor subtypes (5.2 and 1.2 nM, respectively, and modest affinity to hsst4 (41.1 nM)). Our conformational analysis carried out in DMSO‐d6indicates that this compound exists as two structures arising from thetransandcisconfigurations of the peptide bond between Phe7andN‐alkylated Gly8. However, neither conformer exhibits a type II′ β‐turn. This is the first report of a potent bioactive somatostatin analog that does not exhibit a type II′ β‐turn in solution. Molecular dynamics simulations (500 ps) carried out at 300 K indicate that the backbone of compound1is more flexible than other cyclic somatostatin analogs formed by disulfide bonds. Copyright © 2001 European Peptide Society and John W

ISSN:1075-2617    

DOI:10.1002/psc.348

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThe use of 1,3‐diisopropylcarbodiimide (DIC) for the synthesis of cyclic analogues of the hypoglycaemic peptide fragment derived from theN‐terminus of human growth hormone (hGH), namely hGH[6–13], is described. Different strategies were examined to achieve improved yields for the on resin side‐chain to side‐chain cyclization of the corresponding linear peptides containing reverse β‐turn motifs. When compared with the more reactive Castro's reagent, the results confirm that DIC in the presence of HOBt can be successfully employed to minimize the formation of intermolecular oligomeric by‐products associated with the preparation of cyclic hGH[6–14] peptide analogues based on ani→(i+4)Lys→Glu or Glu→Lys cyclization strategy. Copyright © 2001 European Peptide Society a

ISSN:1075-2617    

DOI:10.1002/psc.343

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractA new amino acid derivative with a diol side‐chain,

ISSN:1075-2617    

DOI:10.1002/psc.349

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractIndolicidin is a cationic 13 amino acid peptide amide produced in the granules of bovine neutrophils with the sequence H‐ILPWKWPWWPWRR‐NH2. Indolicidin is both antimicrobial and, to a lesser extent, haemolytic. In order to systematically investigate structure–function relationships, the solid‐phase synthesis of indolicidin and 48 distinct analogues are reported, as well as the characterization of their respective biological properties. Peptides synthesized and characterized include analogues with modified terminal functions, truncations from either terminus, an alanine scan to determine the role of each individual amino acid, specific amino acid exchanges of aromatic, charged and structural residues and several retro‐, inverso‐ and retroinverso‐analogues. Together, characterization of these analogues identifies specific residues involved in antimicrobial or haemolytic activity and suggests a core structure that may form a scaffold for the further development of peptidomimetic analogues of indolicidin. Copyright © 2001 European Peptide Society and John W

ISSN:1075-2617    

DOI:10.1002/psc.351

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThe success of solid phase peptide synthesis is often limited by the aggregation of the growing peptide chains on the resin. Working from the results of a study of model coupling reactions in solution between Z‐Gly‐Phe‐OH and H‐Phe‐OBzl, we have achieved higher efficiency in the repetitive solid phase fragment condensation of VGVAPG, in a 3:1 chloroform‐phenol solvent system, using diisopropylcarbodiimide (DIC) as coupling agent, and a combination of 3‐hydroxy‐3,4‐dihydro‐4‐oxo‐1,2,3‐benzotriazine (HODhbt) and its tetrabutyl ammonium salt as additive, than in DMF with DIC and HODhbt alone. Copyright © 2001 European Peptide Societ

ISSN:1075-2617    

DOI:10.1002/psc.352

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY