Interaction of aliphatid alcohols with cytochrome P-450 from rat liver microsomes
Akhrem, A.A.; Popova, E.M.; Metelitsa, D.I.
Biokhimiia 43(8): 1485-1491
1978
ISSN/ISBN: 0320-9725 PMID: 32928 Document Number: 137980
The interaction of aliphatic alcohols and cyclohexanol with microsomal cytochrome P-450 was investigated. All alcohols induced the modified 11 type spectral changes. These changes were characterized by .lambda.max = 412 and .lambda.min = 380-382 nm in difference spectra. The Kd of the alcohol cytochrome P-450 complexes were determined. Triton X-100 and pH influenced the Kd values. The interaction of the alcohols with cytochrome P-450 in phosphate buffer, pH 6.0, without Triton X-100 was characterized by 1 Kd value for MeOH, EtOH, n-BuOH and cyclohexanol and by 2 Kd values for i-PrOH, i-BuOH and tert-BuOH. The interaction of the alcohols with cytochrome P-450 in Tris-HCL-buffer (pH 7.5) with Triton X-100 was characterized for all the above alcohols by the Kd values, which were described by the Taft equation with coefficient .rho. = -1.55. This fact confirms the interaction of the OH-groups of the alcohol with heme Fe of cytochrome P-450. The mechanism of interaction of alcohols with cytochrome P-450 was discussed.