In this study, we generated and analyzed the side-chain conformational potential energy hypersurfaces for each of the nine possible backbone conformers for N-acetyl-L-aspartic acid-N' methylamide. We found a total of 27 out of the 81 possible conformers optimized at the B3LYP/6-31G(d) level of theory. The relative energies, as well as the stabilization energies exerted by the side-chain on the backbone, have been calculated for each of the 27 optimized conformers at this level of theory. Various backbone-backbone (N-H⋯O=C) and backbone-side-chain (N-H⋯O=C; N H⋯OH) hydrogen bonds were analyzed. The appearance of the notoriously absent εL backbone conformer may be attributed to such side-chain-backbone (SC/BB) and backbone-backbone (BB/BB) hydrogen bonds.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics