Spectroscopic and computational studies on the adenosylcobalamin-dependent methylmalonyl-CoA mutase: evaluation of enzymatic contributions to Co-C bond activation in the Co(super 3+) ground state

Electronic absorption (Abs) and magnetic circular dichroism (MCD) spectroscopic techniques to probe cofactor/enzyme active site interactions in the Co(super 3+)Cbl 'ground' state for Methylmalonyl-CoA mutase (MMCM) reconstituted with both the native cofactor AdoCbl and its derivative methylcobalamin are analyzed. The results indicate that the dominant contribution to the enzymatic Co-C bond activation presumably comes through stabilization of the Co2+Cbl/Ado post-homolysis products.