| 3-methylcholanthrene | A highly carcinogenic hydrocarbon that can be formed chemically from deoxycholic or cholic acids, or from cholesterol; the choice between 3-or 20-for the methyl group depends upon whether hydrocarbon (inner) or steroid (outer) numbering is chosen; in the latter case, the formal relationship to the cholic acids and cholesterol is clear. (05 Mar 2000) |
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| 3-methylcrotonyl-CoA | (CH3)2C==CHCOSCoA;an intermediate in the degradation of l-leucine; accumulates in a deficiency of 3-methylcrotonyl-CoA carboxylase. 3-methylcrotonyl-CoA carboxylase, an enzyme in the pathway of l-leucine degradation that catalyses the reaction of 3-methylcrotonyl-CoA with CO2, ATP, and water to form ADP, orthophosphate, and 3-methylglutaconyl-CoA; a deficiency of this enzyme causes episodes of severe metabolic acidosis. (05 Mar 2000) |
| 3-methylglutaconic aciduria | Elevated levels of 3-methylglutaconic acid in the urine. An inherited disorder whose mild form is a result of a deficiency of 3-methylglutaconyl-CoA hydratase, leading to delayed speech development. (05 Mar 2000) |
| 3-methylglutaconyl-CoA hydratase | <enzyme> An enzyme that catalyses the reaction of trans-3-methylglutaconyl-CoA and water to form 3-hydroxy-3-methylglutaconyl-CoA; this enzyme participates in the pathway for l-leucine degradation; a deficiency of this enzyme will result in 3-methylglutaconic aciduria. (05 Mar 2000) |
| 3-methylitaconate delta-isomerase | <enzyme> Catalyses reversibly the isomerization of methylitaconate to dimethylmaleate Registry number: EC 5.3.3.6 Synonym: 3-midiase (26 Jun 1999) |
| 3-O-methyl-fluorescein phosphatase | <enzyme> Used for assay of na-k-atpase in intact tissues Registry number: EC 3.6.1.- Synonym: 3-o-methylfluorescein phosphatase (26 Jun 1999) |
| 3-o-methylglucose | <chemical> A non-metabolizable glucose analogue that is not phosphorylated by hexokinase. 3-o-methylglucose is used as a marker to assess glucose transport by evaluating its uptake within various cells and organ systems. (j neurochem 1993;60(4):1498-504) Chemical name: D-glucose, 3-O-methyl- (12 Dec 1998) |
| 3-oxo-5 beta-steroid delta 4-dehydrogenase | <enzyme> Do not confuse with EC 1.3.1.23 (cholestenone 5 beta-reductase) which is also steroid 5 beta-reductase in chemline; do not use for enzyme using NADP-see EC 1.3.1.23 and EC 1.3.1.3 Chemical name: 3-oxo-5 beta-steroid delta(4)dehydrogenase Registry number: EC 1.3.99.6 Synonym: steroid 5 beta-reductase, testosterone 5 beta-reductase, 4-ene-5 beta-reductase, delta(4)-3-ketosteroid-5 beta-(acceptor)-reductase, testosterone 5beta-reductase, delta(4)-5beta-reductase, cytosolic 4-ene-reductase (26 Jun 1999) |
| 3-oxoacid-CoA transferase | <enzyme> An enzyme catalyzing the reversible conversion of acetoacetyl-CoA and succinate into succinyl-CoA and acetoacetate; malonyl-CoA can substitute for succinyl-CoA and a few other 3-oxo acids for the acetoacetate; an important step in order for the ketone bodies to serve as a fuel for extrahepatic tissues. Synonym: 3-ketoacid-CoA transferase, acetoacetyl-succinic thiophorase. (05 Mar 2000) |
| 3-oxoacyl-(acyl-carrier-protein) synthase | <enzyme> An enzyme of long-chain fatty acid synthesis, that adds a two-carbon unit from malonyl-(acyl carrier protein) to another molecule of fatty acyl-(acyl carrier protein), giving a beta-ketoacyl-(acyl carrier protein) with the release of carbon dioxide. Chemical name: Acyl-(acyl carrier protein):malonyl-(acyl-carrier-protein) C-acyltransferase (decarboxylating) Registry number: EC 2.3.1.41 (12 Dec 1998) |
| 3-oxoacyl-ACP reductase | A part of the fatty acid synthase complex; an enzyme reversibly reacting 3-oxoacyl-ACP with NADPH to form d-3-hydroxyacyl-ACP and NADP+. Synonym: beta-ketoacyl-ACP reductase. (05 Mar 2000) |
| 3-oxoacyl-ACP synthase | <enzyme> An enzyme condensing malonyl-ACP and acyl-cys-protein to 3-oxoacyl-ACP + cys-protein + CO2, and similar reactions, as steps in fatty acid synthesis; cys-protein is also a part of the fatty acid synthase complex. Synonym: acyl-malonyl-ACP synthase, beta-ketoacyl-ACP synthase. (05 Mar 2000) |
| 3-oxobutyryl-CoA reductase | <enzyme> Nadh-dependent, (s)-specific enzyme from clostridium tyrobutyricum; n-terminal amino acid sequence given in first source Registry number: EC 1.1.1.- (26 Jun 1999) |
| 3-oxosteroid delta(1) dehydrogenase | <enzyme> Cytochrome c used in assay Registry number: EC 1.3.99.4 Synonym: 4-ene-3-oxosteroid (acceptor)-1-ene-oxidoreductase, steroid 1,2-dehydrogenase, 4-en-3-oxosteroid-(acceptor)-1-en oxidoreductase, steroid-1-dehydrogenase, 3-ketosteroid delta(1) dehydrogenase (26 Jun 1999) |
| 3-phenylpyruvate aminotransferase | <enzyme> L-glutamate is amino-donor; forms phenylalanine Registry number: EC 2.6.1.- (26 Jun 1999) |