Cholesterol is hydroxylated to 27-hydroxycholesterol by CYP27 Authored: Jassal, B, 2008-05-19 12:57:01 Cholesterol, NADPH + H+, and O2 react to form 27-hydroxycholesterol, H2O, and NADP+, in the mitochondrial matrix, catalyzed by CYP27A1. 27-Hydroxycholesterol is the most abundant oxysterol in the plasma in humans; its formation is thought to play a central role in the mobilization of cholesterol from non-hepatic tissues. Edited: D'Eustachio, P, 2007-04-30 14:43:26 Pubmed10428977 Pubmed1708392 Reactome Database ID Release 43192123 Reactome, http://www.reactome.org ReactomeREACT_9953 Reviewed: D'Eustachio, P, 2008-05-28 08:30:54 cholesterol + NADPH + H+ + O2 => 27-hydroxycholesterol + H2O + NADP+