Conformational analysis of Be(II) and Mg(II) complexes of N-acetyl alanine methyl ester

Abstract

Conformational changes of N-acetyl alanine methyl ester upon binding of Be(II) and Mg(II) have been investigated by means of ab initio MO-SCF calculations with minimal basis set. Results obtained with single step optimized geometries are compared with those computed with full energy gradient optimization. The latter proved to be of far superior quality, but both methods lead to the same prediction towards the most stable complex structure, which are chelate complexes with simultaneous ion binding to peptide and ester group. This conformation involves drastic structural changes in the ligand molecule, hence indicating the ions' ability to induce some conformational changes also in biological macromolecules with similar functional groups. © 1998.