Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | no activation by 1 mM hydrogen peroxide | Zea mays |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
itraconazole | no inhibition | Zea mays | |
additional information | no inhibition by azole inhibitors, 1 mM, pyrifenox, ketoconazole, and itraconazole, no inhibition by phenobarbital and pyrazole. No inhibition by 1 mM cyanide or 1 mM hydrogen peroxide, insensitive to carbon monooxide | Zea mays |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.003 | - |
NADPH | substrate: DELTA7-chondrillastenone | Zea mays | |
0.004 | - |
NADPH | substrate: cycloeucalenone | Zea mays | |
0.067 | - |
cycloartenone | - |
Zea mays | |
0.085 | - |
24-methylenecycloartanone | - |
Zea mays | |
0.1 | - |
cyclolaudenone | - |
Zea mays | |
0.162 | - |
24-methylenelophenone | - |
Zea mays | |
0.22 | - |
cholestanone | - |
Zea mays | |
0.22 | - |
cycloeucalenone | - |
Zea mays | |
0.245 | - |
DELTA7-chondrillastenone | - |
Zea mays | |
0.26 | - |
obtusifolione | - |
Zea mays | |
0.42 | - |
DELTA7-cholestenone | - |
Zea mays |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | - |
Zea mays | 16020 | - |
microsome | - |
Zea mays | - |
- |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Zea mays | constitutive component of microsomal sterol 4-demethylation complex in photosynthetic organism | ? | - |
? | |
additional information | Zea mays | enzyme of plant sterol biosynthesis, involved in sterol-4 demethylation, invoves the removal of two methyl groups at C4 | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Zea mays | - |
maize, variety LG11 | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
a 3beta-hydroxysteroid + NADP+ = a 3-oxosteroid + NADPH + H+ | stereoselectivity : #1,4,5# catalyzes reduction of the 3-keto group to a 3beta-hydroxyl group <5,6,7> | Zea mays |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
embryo | - |
Zea mays | - |
seedling | - |
Zea mays | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
24-ethylidenelophenone + NADPH | oxidation: poor | Zea mays | 24-ethylidenelophenol + NADP+ | - |
r | |
24-methylenecycloartanone + NADPH | 7% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | 24-methylenecycloartanol + NADP+ | - |
ir | |
24-methylenelophenone + NADPH | 35% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | 24-methylenelophenol + NADP+ | - |
? | |
24-methylenepollinastanone + NADPH + acetate | 70% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | 24-methylenepollinastanol + NADP+ | - |
? | |
24RS-dihydrocycloeucalenone + NADPH | 53% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | 24RS-dihydrocycloeucalenol + NADP+ | - |
? | |
4beta-methyl-28-nor-24RS-dihydrocycloeucalenone + NADPH | 27% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | 4beta-methyl-28-nor-24RS-dihydrocycloeucalenol + NADP+ | - |
? | |
avenastenone + NADPH | more than 72% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | avenasterol + NADP+ | - |
? | |
cholest-7-en-3-one + NADPH | DELTA7-cholestenone, best substrate | Zea mays | 3beta-hydroxy-cholest-7-ene + NADP+ | DELTA7-cholesterol | ir | |
cholestanone + NADPH | 57% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | cholestanol + NADP+ | - |
? | |
cycloartenone + NADPH | 7% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | cycloartenol + NADP+ | - |
ir | |
cycloeucalenone + NADPH + H+ | putative endogenous substrate for sterone reductase | Zea mays | cycloeucalenol + NADP+ | reverse oxidation: about 35% of forward reductase rate | r | |
cycloeucalenone + NADPH + H+ | putative endogenous substrate for sterone reductase | Zea mays | cycloeucalenol + NADP+ | 17-(4-isopropyl-1-methyl-pent-4-enyl)-4,13,14-trimethyl-tetradecahydro-cyclopropa[9,10]cyclopenta[a]phenanthren-3beta-ol | r | |
cycloeucalenone + NADPH + H+ | 68% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | cycloeucalenol + NADP+ | reverse oxidation: about 35% of forward reductase rate | r | |
cycloeucalenone + NADPH + H+ | 68% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | cycloeucalenol + NADP+ | 17-(4-isopropyl-1-methyl-pent-4-enyl)-4,13,14-trimethyl-tetradecahydro-cyclopropa[9,10]cyclopenta[a]phenanthren-3beta-ol | r | |
cyclolaudenone + NADPH | 10% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | cyclolaudenol + NADP+ | - |
? | |
DELTA7-chondrillastenone + NADPH | 70% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | DELTA7-chondrillasterol + NADP+ | 17-(4-ethyl-1,5-dimethyl-hex-2-enyl)-10,13-dimethyl-2,3,4,5,6,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3beta-ol | ? | |
DELTA7-chondrillastenone + NADPH | 5alpha,28beta(H)-stigmasta-7,22-dien-3-one | Zea mays | DELTA7-chondrillasterol + NADP+ | 17-(4-ethyl-1,5-dimethyl-hex-2-enyl)-10,13-dimethyl-2,3,4,5,6,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3beta-ol | ? | |
additional information | substrate specificity | Zea mays | ? | - |
? | |
additional information | coprostanol: not a substrate | Zea mays | ? | - |
? | |
additional information | 3-keto reducing enzyme is specific for a 5alpha, trans A/B ring junction in the sterone substrate, as found in all sterol biosynthesis intermediates | Zea mays | ? | - |
? | |
additional information | 4alpha-methyl-9beta,19-cyclo-C30-sterones and 4-desmethyl-DELTA7-C27-sterones or C30-sterones are preferentially reduced, 4,4-dimethyl-C30-sterones or C31-sterones react poorly. Produces stereoselectively corresponding 3beta-alcohol derivatives, no 3alpha-alcohol product is formed | Zea mays | ? | - |
? | |
additional information | catalyzes NADPH-dependent C-3 reduction of various sterones to produce stereoselectively the corresponding 3beta-hydroxy derivatives | Zea mays | ? | - |
? | |
additional information | constitutive component of microsomal sterol 4-demethylation complex in photosynthetic organism | Zea mays | ? | - |
? | |
additional information | enzyme of plant sterol biosynthesis, involved in sterol-4 demethylation, invoves the removal of two methyl groups at C4 | Zea mays | ? | - |
? | |
obtusifolione + NADPH | 43% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | obtusifoliol + NADP+ | 4,14-dimethyl-ergosta-8,24(28)-dien-3-ol | ? | |
obtusifolione + NADPH | 4,14-dimethyl-ergosta-8,24(28)-dien-3-one | Zea mays | obtusifoliol + NADP+ | 4,14-dimethyl-ergosta-8,24(28)-dien-3-ol | ? | |
spinastenone + NADPH | 32% compared with cholest-7-en-3-one, DELTA7-cholestenone | Zea mays | spinasterol + NADP+ | - |
? |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | essentially inactive with NADH | Zea mays | |
NADP+ | oxidation, poorly, only few substrates | Zea mays | |
NADPH | specific for NADPH, NADH is essentially inactive, less than 10% | Zea mays |