ELUCIDATION OF VANCOMYCINS ENANTIOSELECTIVE BINDING-SITE USING ITS COPPER COMPLEX

Vancomycin forms a stable complex with CU2+ in neutral aqueous solutio ns. The enantioselectivity of native vancomycin was compared to that o f the copper-vancomycin complex using capillary electrophoresis (CE). There were significant differences in their enantioselectivities. This can be attributed to the fact that copper ion coordinates with some o f the same functional groups in vancomycin that are essential for chir al recognition and enantioresolution. An amine moiety that provides on e of the more important enantioselective interactions was identified. This chiral interaction site was illustrated using a color-coded, spac e-filling model of the X-ray crystal structure of the copper-vancomyci n complex. Successful enantioselective interactions at lower pHs were attributed to the partial dissociation of the copper-vancomycin comple x. (C) 1997 Wiley-Liss, Inc.