Rueffer M, Nagakura N, Zenk M H
Lehrstuhl Pharmazeutische Biologie der Universität München, D-8000 München 2, Federal Republic of Germany.
Planta Med. 1983 Nov;49(11):131-7. doi: 10.1055/s-2007-969833.
A new enzyme, S-adenosylmethionine: (R), (S)-norlaudanosoline-6-O-methyltransferase, was isolated from the soluble protein extract of A. PLATYCERAS cell cultures and purified approximately 80-fold. This enzyme catalyses the formation of 6-O-methylnorlaudanosoline, and, to a minor extent, 7-O-methylnorlaudanosoline from SAM and (S), as well as (R), norlaudanosoline. The apparent molcular weight of the enzyme is 47000 Dalton. The pH-optimum of the enzyme is 7.5, the temperature optimum, 35 degrees C. Apparent K (M) values for (S) and (R)-norlaudanosoline were 0.2 mM, and for SAM, 0.05 mM. The transferase shows high substrate specificity for tetrahydrobenzylisoquinoline alkaloids. Simple orthophenols, like phenylpropane derivatives, coumarins or flavonoids, are not accepted as substrates. The enzyme is widely distributed in benzylisoquinoline-containing plant cell cultures and is present in differentiated plants like PAPAVER SOMNIFERUM.
一种新的酶，S-腺苷甲硫氨酸：(R)，(S)-去甲劳丹索林-6-O-甲基转移酶，从PLATYCERAS细胞培养物的可溶性蛋白提取物中分离出来，并纯化了约80倍。这种酶催化从SAM和(S)以及(R)-去甲劳丹索林形成6-O-甲基去甲劳丹索林，在较小程度上还形成7-O-甲基去甲劳丹索林。该酶的表观分子量为47000道尔顿。该酶的最适pH为7.5，最适温度为35℃。(S)和(R)-去甲劳丹索林的表观K(M)值为0.2 mM，SAM的表观K(M)值为0.05 mM。该转移酶对四氢苄基异喹啉生物碱表现出高底物特异性。简单的邻苯酚，如苯丙烷衍生物、香豆素或黄酮类化合物，不被接受作为底物。该酶广泛分布于含苄基异喹啉的植物细胞培养物中，并存在于像罂粟这样的分化植物中。
