CONFORMATIONALLY RESTRAINED PEPTIDES - CRYSTAL-STRUCTURE OF L-ALANYL-D-ALANYL-D-AMINOSUCCINYL-GLYCYL-L-ALANINE METHYL-ESTER

Citation
D. Demasi et al., CONFORMATIONALLY RESTRAINED PEPTIDES - CRYSTAL-STRUCTURE OF L-ALANYL-D-ALANYL-D-AMINOSUCCINYL-GLYCYL-L-ALANINE METHYL-ESTER, International journal of peptide & protein research, 47(4), 1996, pp. 227-230
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology
ISSN journal
0367-8377
Volume
47
Issue
4
Year of publication
1996
Pages
227 - 230
Database
ISI
SICI code
0367-8377(1996)47:4<227:CRP-CO>2.0.ZU;2-F
Abstract
The solid-state structure of a heterochiral peptide embodying a D-amin osuccinyl peptide (D-Asu) and a D-Ala was studied in order to analyse the effects of Asu and amino acids with inverse chirality on peptide c onformation. The crystal structure has been determined by X-ray diffra ction techniques and refined to a final R factor of 0.043. The molecul e adopts an unusual overall 'S-shape' conformation due to two consecut ive type II beta-turns. In this molecule it is possible to compare a t ype II beta-bend conformation (L-Ala(1)-D-Ala(2)) favoured by the pres ence of a D-residue at second corner to a type II beta-turn (D-Asu(3)- Gly(4)) favoured by the presence of a D-Asu residue at first corner. I n agreement with previous studies, this structure confirms that the As u has a high propensity to adopt a type II or II' beta-bend conformati on and that it may be used as a strong determinant of these structural motifs. (C) Munksgaard 1996.