[Biosynthesis of tritium-labeled S-adenosyl-L-methionine in yeast cells]

Biosynthetic preparation of S-adenosyl-L-[methyl-3H]methionine from L-[methyl-3H]methionine by cultivation of diploid yeast Saccharomyces cerevisiae (methionine-auxotrophic) in a cultural medium with the high concentration of L-methionine is described. The radiochemical purity was over 95%. Biological activity of the preparations has been shown in transmethylation reactions in the presence of the yeast homocysteine-methyltransferase.