Ab initio SCF and force-field calculations on low-energy conformers of 2-acetylamino-2,N-dimethylpropanamide

摘要: The understanding of the conformational properties α,α-disubstituted amino acids is related to design structural mimics for proteins. More specifically, 2-amino-2-methylpropanoic acid has been widely used in constructing helical peptide modules. In this paper, we report results ab initio SCF calculations with 3-21G, 6-31G* and 6-31G** basis sets on four low-energy conformations 2-acetylamino-2,N-dimethylpropanamide. are assess reliability empirical potentials force-field methodologies. For purpose, averaged multiple conformations' atomic point charges were determined 6-31 G* set. some important deficiencies current force-fields. Thus, relative energies dipeptide excessive repulsive or attractive interactions not well described by potentials.