Narasimhulu S
Biochim Biophys Acta. 1979 Oct 5;556(3):457-68. doi: 10.1016/0005-2736(79)90133-0.
The addition of cholate to the microsomes at 37.5 degrees C resulted in a striking decrease in the apparent substrate dissociation constant (K's) and its temperature dependency. The microsomal membranes depleted of 80% of the lipids preserved the temperature dependency of the Ks and exhibited breaks in the Van't Hoff plot at the characteristic temperature of the lipids phase transition. The results indicate that the cytochrome P-450 is considerably restrained from expressing its maximum substrate binding potential at physiological temperature. In addition, the results indicate that the majority of the lipids apparently do not play a significant role in imposing constraint on the substrate-cytochrome -450 binding reaction and in the temperature dependency of the Ks.
在37.5摄氏度下向微粒体中添加胆酸盐，导致表观底物解离常数（K's）及其温度依赖性显著降低。脂质减少80%的微粒体膜保留了Ks的温度依赖性，并且在脂质相变的特征温度下，范特霍夫图出现断点。结果表明，细胞色素P - 450在生理温度下其最大底物结合潜力受到相当大的限制。此外，结果表明，大多数脂质显然在对底物 - 细胞色素 - 450结合反应施加限制以及Ks的温度依赖性方面不起重要作用。
