An S-adenosyl-l-methionine; coniine methyltransferase from Conium maculatum

Evidence is presented for a cell free system from Conium maculatum which catalyses the transfer of a methyl group from S-adenoysl-l-methionine to coniine with the formation of N-methyl coniine. Maximum enzyme activity which occurred in the unripe fruits was enhanced by dithiothreitol, and evidence for the role of sulphydryl groups of the enzyme was obtained from inhibition with p-CMB, iodoacetamide and N-methyl maleimide. A divalent metal cation dependency was not detected.