Obata T, Hirai T, Kobayashi S, Sho S, Yasuhara H
Nihon Yakurigaku Zasshi. 1985 Jan;85(1):23-31. doi: 10.1254/fpj.85.23.
Molecular weights of mitochondrial type B monoamine oxidase (MAO) in guinea pig brain, liver and kidney were estimated, and their identities and multiplicity were studied. We ascertained what concentration of 3H-pargyline bound to type B MAO specifically from the inhibition curve toward serotonin (5-HT) and beta-phenylethylamine (beta-PEA) by pargyline. Pargyline irreversibly binds to FAD in MAO at a one to one molecular ratio. 3H-pargyline bound to type B MAO specifically and irreversibly by incubation for 5 hr at 37 degrees C, and SDS-disc electrophoresis was carried out using 3H-pargyline as a tracer. The molecular weight of MAO was estimated after specific binding of pargyline was corrected for non-specific binding. The molecular weight of type B MAO in every organ was found to be 60,000, giving a single peak after solubilization with 6% SDS, but several peaks at higher molecular weight were found in each organ after solubilization with 2% SDS. In the brain, there appeared to be a peak of 100,000, and it was suggested that the MAO existed as a dimer which was composed of a FAD containing subunit and a low molecular weight subunit containing no FAD. In the liver, there appeared to be peaks of 120,000 and 240,000, and it was suggested that the MAO existed as a dimer and tetramer. In the kidney, there appeared to be a peak of 180,000, and MAO was suggested to exist as a trimer.
我们估算了豚鼠脑、肝和肾中线粒体B型单胺氧化酶（MAO）的分子量，并研究了它们的同一性和多样性。我们根据帕吉林对血清素（5-HT）和β-苯乙胺（β-PEA）的抑制曲线，确定了与B型MAO特异性结合的3H-帕吉林的浓度。帕吉林以1:1的分子比例与MAO中的黄素腺嘌呤二核苷酸（FAD）不可逆结合。3H-帕吉林在37℃下孵育5小时后特异性且不可逆地与B型MAO结合，并以3H-帕吉林作为示踪剂进行十二烷基硫酸钠圆盘电泳（SDS-圆盘电泳）。在对帕吉林的非特异性结合进行校正后，估算了MAO的分子量。发现每个器官中B型MAO的分子量均为60,000，在用6%十二烷基硫酸钠（SDS）溶解后呈现单峰，但在用2%SDS溶解后，每个器官中均发现了几个分子量更高的峰。在脑中，似乎有一个100,000的峰，提示MAO以二聚体形式存在，该二聚体由一个含FAD的亚基和一个不含FAD的低分子量亚基组成。在肝中，似乎有120,000和240,000的峰，提示MAO以二聚体和四聚体形式存在。在肾中，似乎有一个180,000的峰，提示MAO以三聚体形式存在。
