Separation of two forms of cytochrome <i>P</i>450 adrenal cortex mitochondria

Abstract

The separation of two distinct forms of cytochrome P450 from adrenal cortex mitochondria has been achieved by the following steps; (1) lyophilisation (2) iso-octane extraction, (3) (NH(4))(2)SO(4) fractionation in the presence of sodium cholate. The fraction precipitating between 25-35 percent (NH(4))(2)SO(4) gave a difference spectrum with 11-deoxycorticosterone (11-DOC) but not with 20alpha-hydroxycholesterol (20alpha-HOC). This fraction showed high 11beta-hydroxylase activity but low activity for side chain cleavage of cholesterol (S.C.C.). The fraction precipitating between 45-60 percent (NH(4))(2)SO(4) gave a difference spectrum with 20alpha-HOC but not with 11-DOC and exhibited high S.C.C. activity but low 11beta-hydroxylase activity. The absorption spectrum of the 45-60 percent fraction indicated a preponderance of high spin hemoprotein (lambda(max) 395 nm).