Action of phospholipase A2 on bilayers. Effect of fatty acid and lysophospholipid additives on the kinetic parameters.
Action of phospholipase A2 on bilayers. Effect of fatty acid and lysophospholipid additives on the kinetic parameters.
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磷脂酶 A2 对双层的作用。
DOI：
10.1016/0005-2736(85)90450-x
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Jahagirdar,DV
中科院分区：
文献类型：
--
作者：
Jain,MK;Jahagirdar,DV
本文研究了猪胰磷脂酶A_2对二酰基磷脂酰胆碱、1-酰基溶血磷脂酰胆碱和脂肪酸三元共分散体系的作用。结合和动力学常数被发现是相同的各种条件下。这些参数和催化周转数的三元共分散体的相变温度的变化，和最佳的结合，动力学和催化常数被认为是在横向分离的相之间存在平衡的相变范围内。改变三种组分中任何一种的结构的效果也是通过改变它们的三元共分散体的相变温度。这些观察结果表明，猪胰腺磷脂酶A2的底物界面上的缺陷位点的结合决定了水解的初始速率的底物浓度依赖性，和催化营业额由绑定酶也取决于双分子层的相态。添加剂诱导的稳定化的缺陷在基板的双层被假定占增强的结合的酶的双层。
Action of pig pancreatic phospholipase A2on the ternary codispersions of diacylphosphatidylcholine, 1-acyllysophosphatidylcholine and fatty acids is examined. The binding and kinetic constants are found to be the same under a variety of conditions. These parameters and the catalytic turnover number change with the phase-transition temperature of the ternary codispersions, and optimal binding, kinetic and catalytic constants are seen in the phase-transition range where an equilibrium exists between laterally separated phases. The effect of changing the structure of any of the three components is also via a change in the phase-transition temperature of their ternary codispersions. These observations suggest that the binding of pig pancreatic phospholipase A2to the defect sites on the substrate interface determines the substrate concentration dependence of the initial rate of hydrolysis, and the catalytic turnover by the bound enzyme also depends upon the phase state of the bilayer. An additive-induced stabilization of the defects in the substrate bilayer is postulated to account for the enhanced binding of the enzyme to the bilayer.