Premium
Conformational effects on peptide aggregation in organic solvents: Spectroscopic studies of two chemotactic tripeptide analogs
Author(s) -
Raj P. Antony,
Balaram P.
Publication year - 1985
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360240703
Subject(s) - chemistry , tripeptide , peptide , chloroform , hydrogen bond , stereochemistry , chemotaxis , nuclear magnetic resonance spectroscopy , peptide bond , two dimensional nuclear magnetic resonance spectroscopy , organic chemistry , molecule , biochemistry , receptor
Abstract The aggregation behavior of the chemotactic peptide analogs, Formyl‐Met‐Leu‐Phe‐OMe ( 1 ) and Formyl‐Met‐Aib‐Phe‐OMe ( 2 ), has been studied in chloroform and dimethylsulfoxide over the concentration range of 0.2–110 m M by 1 H‐nmr spectroscopy. Both peptides associate in CDCl 3 at concentrations ≥ 2 m M , while there is no evidence for aggregation in (CD 3 ) 2 SO. Analog 1 adopts an extended conformation in both solvents favoring association to form β‐sheet structures. A folded, γ‐turn conformation involving a 3 → 1 hydrogen bond between Met CO and Phe NH is supported by 1 H‐, 13 C‐nmr, and ir studies of analog 2 . The influence of backbone conformation on the ease of peptide aggregation is demonstrated by ir studies in CHCl 3 and CD studies in dioxane.