Akhrem A A, Popova E M, Metelitsa D I
Biokhimiia. 1978 Aug;43(8):1485-91.
The interaction of alyphatic alcohols and cyclohexanol with cytochrome P-450 in microsomes has been investigated. All alchohols induced the modified 11 type spectral changes by mixing with microsomes. These changes are characterized by lambdamax = 412 and lambdamin = 380-382 nm in difference spectra. The dissociation constants of the alcohol cytochrome P-450 complexes are determined. On this dissociation constants influence pH and Triton X-100 presence. The interaction of the alcohols with cytochrome P-450 in phosphate buffer pH = 6,0 in the detergents absence is characterized by one dissociation constant for MeOH, EtOH, n-BuOH and cyclohexanol and by two dissociation constants for i-PrOH, i-BuOH and tert.-BuOH. The interaction of the alcohols with cytochrome P-450 in Tris-HCL-buffer (pH 7.5) in the Triton X-100 presence is characterized for all above alcohols by the dissociations constants, which are described by Taft equation with coefficient rho =-1.55. This fact confirms the interaction of alcohols HO-groups with heme iron of cytochrome P-450. The scheme of interaction of alcohols with cytochrome P-450 is discussed.
研究了脂肪醇和环己醇与微粒体中细胞色素P-450的相互作用。所有醇类与微粒体混合后均诱导了修饰的Ⅱ型光谱变化。这些变化在差示光谱中的特征为λmax = 412，λmin = 380 - 382 nm。测定了醇 - 细胞色素P-450复合物的解离常数。pH值和Triton X-100的存在会影响该解离常数。在无去污剂的pH = 6.0的磷酸盐缓冲液中，甲醇、乙醇、正丁醇和环己醇与细胞色素P-450的相互作用以一个解离常数为特征，而异丙醇、异丁醇和叔丁醇以两个解离常数为特征。在Triton X-100存在的Tris - HCL缓冲液（pH 7.5）中，上述所有醇类与细胞色素P-450的相互作用均以解离常数为特征，这些解离常数由塔夫脱方程描述，系数ρ = -1.55。这一事实证实了醇类的羟基与细胞色素P-450的血红素铁之间的相互作用。讨论了醇类与细胞色素P-450的相互作用机制。
