Premium
Conformation of histidine model peptides. I. Conformational energy calculations for L ‐alanyl‐ L ‐histidine diketopiperazine
Author(s) -
Grebow Peter E.,
Hooker Thomas M.
Publication year - 1974
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.1974.360131115
Subject(s) - chemistry , imidazole , dipeptide , protonation , histidine , ring (chemistry) , molecule , stereochemistry , peptide , crystallography , amino acid , biochemistry , organic chemistry , ion
Semiempirical conformational energy calculations were carried out for the cyclic dipeptide L ‐alanyl‐ L ‐histidine diketopiperazine. The results indicate that electrostatic effects are probably significant in determining the conformation assumed by this molecule. When the imidazole group is in its uncharged state the most stable conformations of the molecule are those with the imidazole ring folded over the diketopiperazine ring (χ 1 = 60°). Upon protonation of the imidazole group the folded conformation may be destabilized relative to conformations characterized by χ 1 positions near 180°.