CYP7B1 oxysterol 7alpha-hydroxylase;
cholest-5-ene-3beta,25-diol,NADPH:oxygen oxidoreductase (7alpha-hydroxylating);
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor
cholest-5-ene-3beta,25/26-diol,[NADPH---hemoprotein reductase]:oxygen oxidoreductase (7alpha-hydroxylating)
(1) cholest-5-ene-3beta,25-diol + [reduced NADPH---hemoprotein reductase] + O2 = cholest-5-ene-3beta,7alpha,25-triol + [oxidized NADPH---hemoprotein reductase] + H2O [RN:
(2) (25R)-cholest-5-ene-3beta,26-diol + [reduced NADPH---hemoprotein reductase] + O2 = (25R)-cholest-5-ene-3beta,7alpha,26-triol + [oxidized NADPH---hemoprotein reductase] + H2O [RN:
[reduced NADPH---hemoprotein reductase] [CPD:
[oxidized NADPH---hemoprotein reductase] [CPD:
A P-450 (heme-thiolate) protein. Unlike EC
, 24-hydroxycholesterol 7alpha-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 . The direct electron donor to the enzyme is EC
, NADPH---hemoprotein reductase.
EC 18.104.22.168 created 2005 as EC 22.214.171.124, modified 2013 (EC 126.96.36.199 created 1999, incorporated 2013), transferred 2016 to EC 188.8.131.52
ec00120 Primary bile acid biosynthesis
ec00140 Steroid hormone biosynthesis
K07430 25/26-hydroxycholesterol 7alpha-hydroxylase
SANH: 107659553 107690180
CCAR: 109070086 109073141
CAUA: 113045069 113120109 113120636
TNG: GSTEN00005656G001 GSTEN00010553G001
SLUC: 116056359 116056373
MSAM: 119896733 119902807
SASA: 106569045 106599438(CP7B1)
SALP: 111956752 111979270
BBEL: 109463792 109465379 109468210 109472486 » show all
Martin KO, Budai K, Javitt NB
Cholesterol and 27-hydroxycholesterol 7 alpha-hydroxylation: evidence for two different enzymes.
J Lipid Res 34:581-8 (1993)
Toll A, Wikvall K, Sudjana-Sugiaman E, Kondo KH, Bjorkhem I.
7 alpha hydroxylation of 25-hydroxycholesterol in liver microsomes. Evidence that the enzyme involved is different from cholesterol 7 alpha-hydroxylase.
Li-Hawkins J, Lund EG, Bronson AD, Russell DW
Expression cloning of an oxysterol 7alpha-hydroxylase selective for 24-hydroxycholesterol.
Ren S, Marques D, Redford K, Hylemon PB, Gil G, Vlahcevic ZR, Pandak WM
Regulation of oxysterol 7alpha-hydroxylase (CYP7B1) in the rat.
The enzymes, regulation, and genetics of bile acid synthesis.