Interaction of vanadate (H2VO4-) with dipeptides investigated by 51V NMR spectroscopy

The complexation of vanadates by dipeptides has been studied, and the results are reported herein. The simple dipeptides selected with respect to the elucidation of their mode of coordination contained glycine at the N-terminal end. It is also known that acidic side chains of the protein matrix are likely to be involved in the vanadate coordination in vanadate-dependent peroxidase. At pH 7.5 and at overall vanadium concentrations of 10 mmol/L, the species present in solution are H2VO4-, H2V2O7-, V4O124-, and V5O155-. Another possible species present is V6O186-. 51V NMR spectroscopy was used to elucidate the vanadate species. 27 refs., 3 figs., 2 tabs