| beta-cystathionase | <enzyme> An enzyme catalyzing the hydrolysis of l-cystathionine to pyruvate, l-homocysteine, and NH3. See: cystathionine gamma-lyase. Synonym: beta-cystathionase, cystine lyase. (05 Mar 2000) |
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| beta-d thalassaemia | Thalassaemia due to a gene that depresses synthesis of both beta-and d-globin chains by the chromosome bearing the abnormal gene. Heterozygous state: thalassaemia minor with Hb F comprising 5 to 30% of total haemoglobin but distributed unevenly among cells, Hb A2 reduced or normal. Homozygous state: moderate anaemia with only Hb F present, no Hb A or Hb A2. Synonym: F thalassaemia. (05 Mar 2000) |
| beta-D-fucosidase | <enzyme> Catalyses hydrolysis of terminal non-reducing beta-d-fucose residues in beta-d-fucosides; also hydrolyzes beta-d-galactosides Registry number: EC 3.2.1.38 Synonym: beta-d-fucoside fucohydrolase (26 Jun 1999) |
| beta-d-galactosidase | A sugar-splitting enzyme that catalyses the hydrolysis of lactose into d-glucose and d-galactose, and that of other beta-d-galactosides; it also catalyses galactotransferase reactions; a deficiency of beta-d -galactosidase leads to problems in the intestinal digestion of lactose; used in the production of milk products for adults who do not have the intestinal enzyme; a defect of one isozyme of beta-d-galactosidase is associated with Morquio's syndrome type B. Compare: lactase persistence, lactase restriction. Synonym: lactase. (05 Mar 2000) |
| beta-D-galactoside alpha 2-6-sialyltransferase | <enzyme> Catalyses the reaction of cmp-n-acetylneuraminate and galactosylglycoprotein to yield cmp and n-acetylneuraminylgalactosylglycoprotein; cd75 and cd75w antigen were removed as sys - it is not equivalent to the enzyme. Registry number: EC 2.4.99.1 Synonym: cmp-n-acetylneuraminate-d-galactosyl-glycoprotein n-acetylneurainyltransferase, cmp-n-acetylneuraminate-beta-galactoside alpha-2,6-sialyltransferase, beta-galactosyl(1-4)n-acetylglucosaminide alpha(2-6)-sialyltransferase, gal-glcnac(2-6)-sialyltransferase, cmp-n-acetylneuraminic acid-lactose sialytransferase, cmp-acetylneuraminate galactoside (alpha 2-6)-sialyltransferase, cmp-n-acetylneuraminate-galactosylglycoprotein sialyltransferase, alpha 2-6-sialyltransferase, cmp-sialic acid-n-acetyllactosaminide alpha (2-6)-sialyltransferase, cmp-neuac-galactoside (alpha 2-6)-sialyltransferase, gal-1-4-glcnac alpha(2-6)-sialyltransferase, siat-1, beta-galctoside alpha2,6-sialyltransferase (26 Jun 1999) |
| beta-d-glucosidase | A glucohydrolase similar to alpha-d-glucosidase, but attacking beta-glucosides and releasing beta-d-glucose. Synonym: amygdalase, cellobiase, gentiobiase. (05 Mar 2000) |
| beta-d-glucuronidase | <enzyme> An enzyme catalyzing the hydrolysis of various beta-d-glucuronides, liberating free d-glucuronic acid and an alcohol; a deficiency of this enzyme is associated with Sly syndrome. Synonym: glusulase, glycuronidase. (05 Mar 2000) |
| beta-d-glucuronidase deficiency | A rare deficiency of beta-d-glucuronidase; an autosomal recessive disorder with several allelic forms, characterised by abnormal mucopolysaccharide metabolism leading to progressive mental deterioration, splenic and hepatic enlargement, and dysostosis multiplex. Synonym: mucopolysaccharidase. (05 Mar 2000) |
| beta-D-mannosidase | <enzyme> Catalyses hydrolysis of terminal, non-reducing beta-d-mannose residues in beta-d-mannosides Registry number: EC 3.2.1.25 Synonym: mannanase, beta-mannosidase, mana gene product (26 Jun 1999) |
| beta-DNA | <molecular biology> The normal form of DNA found in organisms, which exists as a right-handed helix. (09 Oct 1997) |
| beta-endorphin | <chemical> A peptide consisting of amino acid sequence 61-91 of the endogenous pituitary hormone beta-lipotropin. The first four amino acids show a common tetrapeptide sequence with methionine- and leucine enkephalin. The compound shows opiate-like activity. Injection of beta-endorphin induces a profound analgesia of the whole body for several hours. This action is reversed after administration of naloxone. Chemical name: beta-Endorphin (12 Dec 1998) |
| beta-farnesene | 7,11-Dimethyl-3-methylene-1,6,10-dodecatriene;one of the two isomers (trans) that occurs in the alarm pheromone of some aphids and also in various essential oils. (05 Mar 2000) |
| beta-farnesene synthase | <enzyme> Catalyses conversion of farnesyl diphosphate to beta-farnesene; genbank af024615 Registry number: EC 3.6.1.- (26 Jun 1999) |
| beta-fructofuranosidase | Beta-h-Fructosidase;an enzyme hydrolyzing beta-d-fructofuranosides and releasing free d-fructose; if the substrate is sucrose, the product is d-glucose plus d-fructose (invert sugar); invert sugar is more easily digestible than sucrose. Synonym: invertase, invertin, saccharase. (05 Mar 2000) |
| beta-galactanase | <enzyme> Appears around day 7 of embryo development of the mollusc pomacea sp; responsible for the degradation of acidic beta-galactan to galactose and di- and tri-galactosides; see also exo-1,4-beta-galactanase and endo-1,4-beta galactanase Registry number: EC 3.2.1.- (26 Jun 1999) |