20alpha,22beta-hydroxycholesterol is cleaved by CYP11A1 to yield pregnenolone and isocaproaldehyde 20alpha,22beta-hydroxycholesterol + NADPH + H+ + O2 => pregnenolone + isocaproaldehyde + NADP+ + H2O 20alpha,22beta-hydroxycholesterol, NADPH + H+, and O2 react to form pregnenolone, isocaproaldehyde, NADP+ and H2O. This cleavage reaction is catalyzed by CYP11A (P450scc) associated with the inner mitochondrial membrane. Pregnenolone is substantially more hydrophilic than cholesterol and hydroxycholesterol and is released into the mitochondrial matrix. Authored: Jassal, B, 2008-10-01 13:18:42 EC Number: 1.14.15.6 Edited: Jassal, B, 2007-04-20 21:09:56 Pubmed3024157 Pubmed9578606 Reactome Database ID Release 43193101 Reactome, http://www.reactome.org ReactomeREACT_10035 Reviewed: D'Eustachio, P, 2007-04-20 21:11:21 Reviewed: D'Eustachio, P, 2008-05-28 08:30:54 has a Stoichiometric coefficient of 2