Baker S P, Hemsworth B A
Eur J Biochem. 1978 Dec 1;92(1):165-74. doi: 10.1111/j.1432-1033.1978.tb12734.x.
The effect of phospholipid depletion by phospholipases on the properties and formation of monoamine oxidase A and B been investigated. The enzyme was solubilized, partially purified, treated with phospholipases and subjected to get filtration to reduce the amount of enzyme-associated phospholipids. Phospholipase A treatment of the purified monoamine oxidase fraction had no effect on the deprenil inhibition pattern or the observed transition temperatures in the Arrhenius plots. However, the rate of enzyme inactivation by heat and trypsin were greatly increased but differences in rates of inactivation of monoamine oxidase A and B were still observed. Phospholipase C treatment of the enzyme fraction had no effect on the deprenil inhibition pattern, Arrhenius plots, heat stability or trypsin digestibility. The inhibition pattern of membrane-bound monoamine oxidase and the phospholipase-treated fractions by propargylamine showed a reduced substrate specificity compared to deprenil suggesting a hydrophobic region in the enzyme is a factor involved in the structural differences of monoamine oxidase A and B.
研究了磷脂酶对磷脂的消耗对单胺氧化酶A和B的性质及形成的影响。将该酶溶解、部分纯化，用磷脂酶处理并进行凝胶过滤以减少与酶相关的磷脂量。用磷脂酶A处理纯化的单胺氧化酶组分对去甲丙咪嗪抑制模式或阿累尼乌斯图中观察到的转变温度没有影响。然而，热和胰蛋白酶使酶失活的速率大大增加，但仍观察到单胺氧化酶A和B失活速率的差异。用磷脂酶C处理酶组分对去甲丙咪嗪抑制模式、阿累尼乌斯图、热稳定性或胰蛋白酶消化率没有影响。与去甲丙咪嗪相比，炔丙胺对膜结合单胺氧化酶和经磷脂酶处理的组分的抑制模式显示出底物特异性降低，这表明酶中的疏水区域是参与单胺氧化酶A和B结构差异的一个因素。
