Exploratory conformational analysis of N-acetyl--Tryptophan-N-methylamide. An ab initio study

MARÍA L. CECI; MARÍA A. LOPEZ VERRILLI; SANDRA S. VALLCANERAS; JOSÉ A. BOMBASARO; ANA M. RODRÍGUEZ; BOTOND PENKE; RICARDO D. ENRIZ

JOURNAL OF MOLECULAR STRUCTURE THEOCHEM

ELSEVIER

Año: 2003 vol. 631 p. 277 - 290

0166-1280

Abstract The full conformational space of N-acetyl--tryptophan-N-methylamide was explored by ab initio MO computations. On the Ramachandran hypersurface of four independent variables E=E(,ø,÷1,÷2), 36 conformers were located instead of the expected 34=81 stable structures. The relative stabilities of the various conformers were analyzed in terms of sidechain?backbone interactions. A comparative study amongst theoretical calculations and experimental (NMR and X-ray) results was carried out. Author Keywords: N-acetyl--Tryptophan-N-methylamide; Peptide conformation; Ab initio MO study; Ramachandran map of tryptophan residue; Sidechain orientation