An exploratory ab initio study of the full conformational space of N-acetyl-L-cysteine-N-methylamide

M ZAMORA; H.A.BALDONI; J. BOMBASARO; M.MAK; A PERCZEL; O.FARKAS; ENRIZ R.D.

JOURNAL OF MOLECULAR STRUCTURE THEOCHEM

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2001 vol. 540 p. 257 - 270

0166-1280

The full conformational space of N-acetyl-L-cysteine-N-methylamide was explored by ab initio MO computations. On the Ramachandran hypersurface of four independent variables E= E(phi, psi, chi (1), chi (2)), 47 conformers were located instead of the expected 3(4) = 81 stable structures. The relativestabilities of the various conformers were analyzed in terms of side-chain-backbone interactions covering both hydrogen bonding and charge-transfer types. The stabilization energies exerted by the side-chain of cysteine on the backbone were compared to those of other amino acids