Adenosylcobalamin

Adenosylcobalamin (AdoCbl), also known as coenzyme B12, cobamamide, and dibencozide, is, along with methylcobalamin (MeCbl), one of the active forms of vitamin B12. Adenosylcobalamin (AdoCbl), also known as coenzyme B12, cobamamide, and dibencozide, is, along with methylcobalamin (MeCbl), one of the active forms of vitamin B12. Adenosylcobalamin participates as a cofactor in radical-mediated 1,2-carbon skeleton rearrangements. These processes require the formation of the deoxyadenosyl radical through homolytic dissociation of the carbon-cobalt bond. This bond is exceptionally weak, with an bond dissociation energy of 31 kcal/mol, which is further lowered in the chemical environment of an enzyme active site. An enzyme that uses adenosylcobalamin as a cofactor is methylmalonyl-CoA mutase (MCM).