Photochemical Action Spectrum of the Terminal Oxidase of Mixed Function Oxidase Systems

See allHide authors and affiliations

Science  22 Jan 1965:
Vol. 147, Issue 3656, pp. 400-402
DOI: 10.1126/science.147.3656.400


The reversal of the carbon monoxide inhibition by bands of monochromatic light was determined for the oxidative demethylation of codeine and monomethyl-4-aminopyrine and the hydroxylation of acetanilide by rat liver microsomes and for the hydroxylation of 17-hydroxyprogesterone at carbon-21 by bovine adrenocortical microsomes. Maximum reversal occurred at 450 millimicrons, the light absorption maximum of the CO compound of the CO-binding pigment of microsomes. The agreement between photochemical action spectrum and spectrophotometric difference spectrum supports the conclusion that the CO-binding pigment is the terminal oxidase of mixed function oxidase systems of mammals.