Premium
Conformational preferences of helix foldamers of γ‐peptides based on 2‐(aminomethyl)cyclohexanecarboxylic acid
Author(s) -
Byun Byung Jin,
Kang Young Kee
Publication year - 2014
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.22287
Subject(s) - chemistry , helix (gastropod) , tetrapeptide , peptide , oligopeptide , dihedral angle , crystallography , gas phase , stereochemistry , chloroform , hydrogen bond , molecule , organic chemistry , ecology , biochemistry , snail , biology
ABSTRACT The conformational preferences of helix foldamers having different sizes of the H‐bonded pseudocycles have been studied for di‐ to octa‐γ 2,3 ‐peptides based on 2‐(aminomethyl)cyclohexanecarboxylic acid (γAmc 6 ) with a cyclohexyl constraint on the C α –C β bond using density functional methods. The helical structures of the γAmc 6 oligopeptides with homochiral configurations are known to be much stable than those with heterochiral configurations in the gas phase and in solution (chloroform and water). In particular, it is found that the (P/M)−2.5 14 ‐helices are most preferred in the gas phase and in chloroform, whereas the (P/M)−2.3 12 ‐helices become most populated in water due to the larger helix dipole moments. As the peptide sequence becomes longer, the helix propensities of 14‐ and 12‐helices are found to increase both in the gas phase and in solution. The γAmc 6 peptides longer than octapeptide are expected to exist as a mixture of 12‐ and 14‐helices with the similar populations in water. The mean backbone torsion angles and helical parameters of the 14‐helix foldamers of γAmc 6 oligopeptides are quite similar to those of 2‐aminocyclohexylacetic acid oligopeptides and γ 2,3,4 ‐aminobutyric acid tetrapeptide in the solid state, despite the different substituents on the backbone. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 87–95, 2014.