Conformational and electronic study of cis-peptide (non-proline residues) ocurring in natutral proteins

” L.J GUTIERREZ, H.A BALDONI, R.D.ENRIZ

JOURNAL OF MOLECULAR STRUCTURE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2009 vol. 934 p. 103 - 111

0022-2860

First-principle computations were carried out on the conformational hyperspace of cis-peptide bond isomers of Ac-Gly-Gly-NHMe, Ac-Gly-Ala-NHMe, Ac-Ala-Gly-NHMe and Ac-Ala-Ala-NHMe. Using the conceptof multidimensional conformational analysis (MDCA), geometry optimisations were performed at B3LYP/6-31G(d) level of theory, and single point energies were calculated at the B3LYP/aug-cc-pVDZ//B3LYP/6-31G(d) level of theory for the corresponding optimized structures. The relative stabilities ofthe various conformers were analysed using the theory of atoms in molecules. The theoretical resultswere compared with some experimental data (X-ray)of Ac-Gly-Gly-NHMe, Ac-Gly-Ala-NHMe, Ac-Ala-Gly-NHMe and Ac-Ala-Ala-NHMe. Using the concept of multidimensional conformational analysis (MDCA), geometry optimisations were performed at B3LYP/6-31G(d) level of theory, and single point energies were calculated at the B3LYP/aug-cc-pVDZ// B3LYP/6-31G(d) level of theory for the corresponding optimized structures. The relative stabilities of the various conformers were analysed using the theory of atoms in molecules. The theoretical results were compared with some experimental data (X-ray) of Ac-Gly-Gly-NHMe, Ac-Gly-Ala-NHMe, Ac-Ala-Gly-NHMe and Ac-Ala-Ala-NHMe. Using the concept of multidimensional conformational analysis (MDCA), geometry optimisations were performed atB3LYP/6-31G(d) level of theory, and single point energies were calculated at the B3LYP/aug-cc-pVDZ//B3LYP/6-31G(d) level of theory for the corresponding optimized structures. The relative stabilities of he various conformers were analysed using the theory of atoms in molecules. The theoretical results were compared with some experimental data (X-ray)