Conformations of the glycine tripeptide analog Ac-Gly-Gly-NHMe: a computational study including aqueous solvation effects.
A computational study of the conformational preferences of the glycine tripeptide analog, Ac-Gly-Gly-NHMe, has been carried out. The molecule is considered in isolation as well as with a continuum model of aqueous solvation. In the absence of solvent, several low-energy conformers are found that exhibit turnlike structures including type I and type II β turns. Upon consideration of aqueous solvation, two conformers, corresponding to the type I and II turn structures are found to be significantly lower in energy than all others. Results from ab initio molecular orbital theory calculations at MP2/aug-cc-pVTZ//MP2/6-311+G(d,p) are compared with those from density functional theory with B3LYP, ωB97X-D, B97-D, and M06-2X as well as several empirical force fields.
Chemistry Department, United States Naval Academy, 572 Holloway Road, Annapolis, Maryland 21402, USA.
Rex E
RE
Atwood
Joseph J
JJ
Urban
D003198:Computer Simulation; D005740:Gases; D005998:Glycine / Q000737:chemistry*; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry*; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D005740:Gases; D010455:Peptides; D012997:Solvents; D014867:Water; D005998:Glycine