S. Mizusaki, Y. Tanabe, M. Noguchi
Sep 1, 1972
Citations
5
Influential Citations
64
Citations
Journal
Phytochemistry
Abstract
Abstract N -Methylputrescine oxidase, catalyzing the oxidative deamination of the primary amino group of N -methylputrescine, was demonstrated in roots of tobacco plants, and purified 150-fold. N -Methylpyrrolinium salt was identified as the reaction product by comparison with the authentic compound. The enzyme had a pH optimum at 8·0 and the K m value for N -methylputrescine was 4·5 × 10 −4 M. Putrescine and cadaverine were also oxidized. Activity of the enzyme was strongly inhibited by carbonyl reagents, thiol inhibitors and diethyldithiocarbamate, but hydrazine derivatives were without significant effect on the enzyme activity. The enzyme was localized exclusively in the roots and its activity markedly increased on decapitation of the shoots. The demonstration of N -methylputrescine oxidase, in addition to putrescine N -methyltransferase, provides evidence that the biosynthetic route of nicotine involves N -methylputrescine and 4-methylaminobutanal ( N -methylpyrrolinium salt) as intermediates.