Nair C P, Noronha J M
Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
Indian J Exp Biol. 1991 Dec;29(12):1112-5.
Vitamin B12 augments thymidylate synthase function in L. leichmannii by facilitating indirectly the availability of suitable nonmethylpolyglutamylfolate cofactors. This is effected by the demethylation of trapped methyltetrahydrofolates, catalysed by a vitamin B12 requiring methionine synthase. Deoxyuridine supplemented cells, lacking in B12, have decreased levels of methionine synthase and thymidylate synthase. Addition of active and inactive conjugase preparation as a source of mono and polyglutamylfolates indicated that the latter are the preferred cofactors for thymidylate synthase.
