a n-methyltransferase in human brain catalyses n-methylation of 1,2,3,4-tetrahydroisoquinoline into n-methyl-1,2,3,4-tetrahydroisoquinoline , a precursor of a dopaminergic neurotoxin , n-methylisoquinolinium ion .
C0025831
methyltransferase
C0025723
methylation