Narasimhulu S
Biochim Biophys Acta. 1977 May 25;487(2):378-87. doi: 10.1016/0005-2760(77)90014-5.
Temperature dependence of the substrate-cytochrome P-450 binding reaction is investigated in the adrenocortical microsomes using 17-hydroxyprogesterone as the substrate. The apparent substrate dissociation constant ("Ks") increases with increase in temperature. Van't Hoff's plot of "Ks" shows breaks at 21 and 31 degrees C. These temperatures correlate well with the lipid phase transition temperatures as determined by the technique of fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene as the probe. The results indicate that the affinity of the substrate depends upon the temperature. In addition the results suggest that changes in the physical state of the lipids is a factor responsible for the temperature dependency of the reaction.
以17 - 羟孕酮为底物，在肾上腺皮质微粒体中研究了底物与细胞色素P - 450结合反应的温度依赖性。表观底物解离常数（“Ks”）随温度升高而增加。“Ks”的范特霍夫曲线在21℃和31℃处出现转折。这些温度与使用1,6 - 二苯基 - 1,3,5 - 己三烯作为探针通过荧光偏振技术测定的脂质相转变温度密切相关。结果表明底物的亲和力取决于温度。此外，结果表明脂质物理状态的变化是反应温度依赖性的一个因素。
