Naoi M, Maruyama W, Zhang J H, Takahashi T, Deng Y, Dostert P
Department of Biosciences, Nagoya Institute of Technology, Japan.
Life Sci. 1995;57(11):1061-6. doi: 10.1016/0024-3205(95)02051-j.
The dopamine-derived alkaloid, 1(R),2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [N-methyl(R)salsolinol] was found to be oxidized enzymatically into the more cytotoxic species, 1,2(N)-dimethyl-6,7-dihydroxyisoquinolinium ion, using enzyme sample prepared from human brain cortex. The values of the Michaelis constant and of the maximum velocity were 912 microM and 1,368 pmol/min/mg protein, respectively. The enzyme was not inhibited by inhibitors of monoamine oxidase, but was sensitive to semicarbazide. The oxidation is discussed in relation to the dopaminergic neurotoxicity of N-methyl-(R)salsolinol.
利用从人脑皮层制备的酶样品，发现多巴胺衍生的生物碱1(R),2(N)-二甲基-6,7-二羟基-1,2,3,4-四氢异喹啉[N-甲基(R)-salsolinol]可被酶促氧化为细胞毒性更强的物质1,2(N)-二甲基-6,7-二羟基异喹啉鎓离子。米氏常数和最大反应速度值分别为912微摩尔和1368皮摩尔/分钟/毫克蛋白质。该酶不受单胺氧化酶抑制剂的抑制，但对半卡巴肼敏感。结合N-甲基-(R)-salsolinol的多巴胺能神经毒性对这种氧化反应进行了讨论。
