1. Abbreviations: 5-methyl-H4-folatc l,N5-methyltetrahydrofolate (L-monoglutamate) 5-methyl-H4-folatc (Glu3) l,N5-methyltetrahydrofolate (λ-L-trklutamate) AMe S-adenosyl-L-methionine AH S-adenosyl-L-homocysteine B12 is used to denote various cobalamins cyano-B12, cyanocobalamin methyl-B12 methyl-cobalamin propyl-B12 propylcobalamin B12r a one-electron reduced derivative of aquo-B12 containing Co2+ B12s a two-electron reduced derivative of aquo-B12 containing Co1+ K3HPO4 potassium phosphate buffer
2. “Transmethylation and Methionine Biosynthesis”;Woods,1965