| 3-hydroxy-3-methylglutaryl-CoA | -OOCCH2C(OH)(CH3)CH2COS-CoA;a key intermediate in the synthesis of ketone bodies and of steroids. Synonym: 3-hydroxy-3-methylglutaryl-CoA. Beta-hydroxy-beta-methylglutaryl-lyase, an enzyme, found primarily in liver and rumen epithelium that catalyses the formation of acetyl-CoA and acetoacetate from beta-hydroxy-beta-methylglutaryl-CoA; a key step in ketogenesis; a deficiency of this enzyme leads to episodes of severe metabolic acidosis without ketosis. Beta-hydroxy-beta-methylglutaryl-reductase, an enzyme that catalyses the rate-limiting step of cholesterol biosynthesis, beta-hydroxy-beta-methylglutaryl-CoA + 2NADPH + 2H+ → mevalonate + 2NADP+ + coenzyme A. Beta-hydroxy-beta-methylglutaryl-synthase, an enzyme in mitochondria that catalyses the reaction of acetyl-CoA with acetoacetyl-CoA and water to form beta-hydroxy-beta-methylglutaryl-CoA and coenzyme A, a step required for both ketogenesis and steroidogenesis to occur. (05 Mar 2000) |
|---|---|
| 3-hydroxy-4-oxoquinoline oxygenase | <enzyme> Forms n-formylanthranilic acid + co2; 24 amino acids of n-terminal sequence given in first source Registry number: EC 1.13.12.- Synonym: 1h-3-hydroxy-4-oxoquinoline oxygenase, 3-oh-4-oxoquinoline oxygenase (26 Jun 1999) |
| 4-(4'-hydroxy-3'-methylbut-2'-enyl)-L-tryptophan synthetase | <enzyme> Enzymatic synthesis of above cpd from isopentenylpyrophosphate and tryptophan Registry number: EC 6.- (26 Jun 1999) |
| 4-hydroxy-2-ketopimelate aldolase | <enzyme> Bacterial enzyme functioning in pathways of aromatic catabolism; forms pyruvate and succinic saemialdehyde Registry number: EC 4.1.3.- (26 Jun 1999) |
| 4-hydroxy-2-ketovalerate aldolase | <enzyme> Forms acetaldehyde + pyruvate; catalyses conversion of 4-hydroxy-2-ketovalerate to pyruvate Registry number: EC 4.1.3.- (26 Jun 1999) |
| 4-hydroxy-2-oxovalerate aldolase | <enzyme> Forms pyruvate + acetaldehyde; enzyme g of p-cumate catabolic pathway in pseudomonas putida Registry number: EC 4.1.3.- Synonym: nahm gene product, cmtg gene product (26 Jun 1999) |
| 4-hydroxy-5-polyprenylbenzoate hydroxylase | <enzyme> Involved in ubiquinone biosynthesis Registry number: EC 1.14.13.- Synonym: 4-oh-5-ppb hydroxylase (26 Jun 1999) |
| 5-hydroxy tryptamine antagonists | Agents which block serotonin receptors and hence interfere with the biological actions of serotonin (5-HT). (05 Mar 2000) |
| 7 alpha-hydroxy-4-cholesten-3-one-12 alpha monooxygenase | <enzyme> Liver microsomal enzyme active in conversion of cholesterol to cholic acid; introduces a 12 alpha-hydroxyl group into the steroid nucleus of cholesterol Registry number: EC 1.14.99.- Synonym: 7-hco-monooxygenase, hco 12 alpha-hydroxylase (26 Jun 1999) |
| 8-hydroxy-2-(di-n-propylamino)tetralin | <chemical> 7-(dipropylamino)-5,6,7,8-tetrahydro-1-naphthalenol. A serotonin 1a-receptor agonist that is being used experimentally to test the effects of serotonin. Pharmacological action: serotonin agonists. Chemical name: 1-Naphthalenol, 7-(dipropylamino)-5,6,7,8-tetrahydro- (12 Dec 1998) |
| 8-hydroxy-5-deazaflavin-dependent DNA photolyase | <enzyme> From anacystis nidulans; purified in streptomyces coelicolor; distinguish from folate-dependent DNA photolyase Registry number: EC 4.1.99.- Synonym: 8-hdfd-DNA photolyase (26 Jun 1999) |
| 8-hydroxy-5-deazaflavin-NADPH oxidoreductase | <enzyme> From streptomyces griseus; mw 42kda; acts as an electron transfer carrier Registry number: EC 1.6.99.- Synonym: hdaf-NADPH oxidoreductase (26 Jun 1999) |
| Rambourg's chromic acid-phosphotungstic acid stain | <technique> A stain for glycoproteins, used with an electron microscope, with which ultrathin tissue sections reveal complex carbohydrates in the same locations as shown by Rambourg's periodic acid-chromic methenamine-silver stain. (05 Mar 2000) |
| a1-acid glycoprotein | <biology> Plasma protein of mammals and birds, 38% carbohydrate. In humans a single chain glycoprotein of 39 kD. Increased levels are associated with inflammation, pregnancy and various diseases. (18 Nov 1997) |
| abscisic acid | <biochemistry> A lipid hormone that inhibits cell growth in plants, it is associated with fruit drop, leaf death and seed dormancy. It is synthesised in the plastids from carotenoids. This hormone helps plants deal with water loss, and its effects can be reversed with gibberellins. (06 May 1997) |