An S-Adenosyl-L-methionine : Cytisine Methyltransferase in Thermopsis Seedlings

Cytisine N-methyltransferase, a new enzyme catalyzing the formation of N-methyl-cytisine (II) from cytisine (I) and S-adenosyl-L-methionine, was found in the seedlings of Thermopsis species. 5-Methyltetrahydrofolic acid did not act as a methyl donor for the N-methylation of cytisine. A magnesium cation dependency was not detected. Some other properties of the enzyme are also described.