Folylpolyglutamate synthetase in Lactobacillus leichmannii: in vitro synthesis and characterization of polyglutamylfolates.

In vitro synthesis of folylpolyglutamates by folylpolyglutamate synthetase from Lactobacillus leichmannii has been studied and optimal conditions for enzyme activity determined. It is found that while ATP (5 mM) is essential for the synthesis of folylpolyglutamates homocysteine augments the same. Replacement of vitamin B12 (2 ng/ml) with deoxyuridine (20 micrograms/ml) in growth medium does not alter the enzymatic parameters studied. DEAE-cellulose column chromatography of in vitro synthesised folylpolyglutamates indicates that folylpolyglutamate synthetase of L. leichmannii can synthesize polyglutamates up to a chain length of four glutamate residues.