Premium
Conformational analysis and helical preferences of normal and α,α‐dialkyl amino acids
Author(s) -
Hodgkin Edward E.,
Clark John D.,
Miller Katherine R.,
Marshall Garland R.
Publication year - 1990
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.360300506
Subject(s) - chemistry , helix (gastropod) , alanine , stereochemistry , amino acid , crystallography , ecology , biochemistry , snail , biology
Energy calculations have been performed on right‐handed helical structures of L ‐alanine and α‐methylalanine oligomers. A new ′3.6 10 ′‐helix is described for α‐methylalanine peptides. The dependence of the relative stability of the α, 3 10 , and 3.6 10 structural forms on helix length, dielectric, and force‐field, in the gas phase, has been studied. Potential energy surfaces for the interconversion of helices have been generated. The 3 10 ‐helix in α‐methylalanine oligomers exhibits a degree of enthalpic and entropic stabilization not observed for alanine. The relevance of the results to the formation of voltage‐sensitive ion channels is discussed.