The right-handed helical conformation (denoted as αL) of a single amino-acid diamide (e.g. HCONHCHCH3CO NH2) is not a minimum energy conformation on the ab initio potential energy surface. Computations performed on oligopeptides [For-(Ala)n NH2, for n ≤ 4], revealed that the helix-like conformations do exist if the backbone conformation at the carboxyl-end is of δL type; i.e. (αL)n - 1δL. This suggests that according to SCF computations, the isolated helices end in a type I β-turn (αLδL).
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry