Substrate induced spin state changes in cytochrome P450

Abstract

Deoxycorticosterone (DOC) produces 385 and 645 nm peaks and 420, 530 and 575 nm troughs, and 20αOH-cholesterol produces 420, 530 and 575 nm peaks and 385 and 645 nm troughs in the difference spectra of adrenal cortical submitochondrial particles. Electron spin resonance studies show that 20αOH-cholesterol produces an increase and 11-deoxycortisol or DOC produce a decrease in the low-spin signal of P450. These results suggest to us that the substrate induced difference spectra may be the result of a spin state shift in cytochrome P450.