Proton nuclear magnetic resonance study of the binary complex of cytochrome P450cam and putidaredoxin: interaction and electron transfer rate analysis

A H-1 nuclear magnetic resonance study of the complex of cytochrome P450cam -putidaredoxin has been performed. Isocyanide is bound to cytochrome p450ca m in order to increase the stability of the protein both in the reduced and the oxidized state. Diprotein complex formation was detected through varia tion of the heme methyl proton resonances which have been assigned in the t wo redox states. The electron transfer rate at equilibrium was determinated by magnetization transfer experiments. The observed rate of oxidation of r educed cytochrome P450 by the oxidized putidaredoxin is 27 (+/- 7) per s, ( C) 1999 Federation of European Biochemical Societies.