Premium
Studies on cyclic peptides. III. The specific interaction of cyclic peptides with benzene and an application of the solvent‐induced nmr shift to the conformational analysis of cyclo‐(Pro‐Sar‐Gly) 2
Author(s) -
Sugihara Toshiharu,
Imanishi Yukio,
Higashimura Toshinobu
Publication year - 1975
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.1975.360140406
Subject(s) - chemistry , benzene , cyclic peptide , chloroform , hydrogen bond , solvent , peptide , proton nmr , stereochemistry , nuclear magnetic resonance spectroscopy , molecule , organic chemistry , biochemistry
The interaction between cyclic peptides [cyclo‐(Sar 4 ), cyclo‐(Pro‐Sar‐Gly) 2 , cyclo‐(Sar‐Sar), and cyclo‐(Sar‐Gly)] with benzene has been investigated by nmr spectroscopy. The experiment with cyclo‐(Sar 4 ) showed that benzene interacted preferentially with the trans peptide bond in a similar manner to the dimethylformamide–benzene interaction. The solvent‐induced nmr shift was then applied to the conformational analysis of cyclo‐(Pro‐Sar‐Gly) 2 with the aid of the molecular model. The major conformation was proved to possess the C 2 symmetry with internally hydrogen‐bonded glycine residues, in which all peptide bonds were trans . The interaction of cyclo‐(Sar‐Sar) and cyclo‐(Sar‐Gly) with benzene was also studied. The association constant was 0.115‐kg solution per mole of cyclo‐(Sar‐Sar) and 0.089‐kg solution per mole of cyclo‐(Sar‐Gly) in chloroform.