A P450 (heme-thiolate) protein. Unlike EC 1.14.14.26, 24-hydroxycholesterol 7¦Á-monooxygenase, which is specific for its oxysterol substrate, this enzyme can also metabolize the oxysterols 24,25-epoxycholesterol, 22-hydroxycholesterol and 24-hydroxycholesterol, but to a lesser extent [2]. The direct electron donor to the enzyme is EC 1.6.2.4, NADPH¡ªhemoprotein reductase.