Ab initio conformational analysis of N- and C-terminally-protected valyl-alanine dipeptide model

Ab initio conformational analysis of the dipeptide Ac-Valine-Alanine-NHMe was performed and optimized at the RHF/3-21g level of theory in an attempt to characterize the folding of short peptides. A topological scan of alanine's (Ala) ψ and ϕ rotors was carried out with valine (Val) in the βL geometry to construct a Ramachandran surface in two- and three-dimensions. It was observed that Val sterically dominates the conformations of Ala. Of the …