| beta-carotene 15,15'-dioxygenase | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
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| beta-carotene cleavage enzyme | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
| beta-carotene hydroxylase | <enzyme> O2-dependent NADPH-dependent monooxygenase from erwinia herbicola; forms zeaxanthin; amino acid sequence has been determined; genbank m87280 Registry number: EC 1.14.13.- Synonym: beta-carotene monooxygenase, crtz gene product (26 Jun 1999) |
| beta cell | 1. <pathology> Cells of the pancreas within discrete endocrine islands (Islets of Langerhans) embedded in the major exocrine tissue of vertebrate pancreas. The B or beta cells (originally distinguished by differential staining from A, C and D), are responsible for synthesis and secretion of insulin, a hormone that controls the level of glucosein the blood. 2. Also refers to the beta cells of the anterior lobe of hypophysis. These are a population of functionally diverse cell's that contain basophilic granules and secrete hormones such as ACTH, lipotropin, thyrotropin, and the gonadotropins. Synonym: basophil cell of anterior lobe of hypophysis. (05 Mar 2000) |
| beta-cell src-homology tyrosine kinase | <enzyme> A murine frk (fyn-related kinase) homolog; genbank l36132; do not confuse with brain-specific kinase bsk Registry number: EC 2.7.1.- Synonym: beta-cell sh tk, bsk protein, sh tk, bsk gene product, sh tk (26 Jun 1999) |
| beta-chlorovinyldichloroarsine | C2H2AsCl3; dichloro(2-chlorovinyl)arsine;a war gas. It is a vesicant, a lung irritant like mustard gas, a systemic poison entering the circulation through the lungs or skin, and a mitotic poison arresting mitosis in the metaphase; dimercaprol is the antidote. Synonym: beta-chlorovinyldichloroarsine. Origin: W. Lee Lewis, U.S. Chemist 1898-1943 (05 Mar 2000) |
| beta conformation | A polypeptide chain (often a secondary structure of a protein) arranged as along zig-zag. (09 Oct 1997) |
| beta-corticotropin | Acid-or pepsin-degraded beta-corticotropin. Synonym: corticotropin. (05 Mar 2000) |
| beta-cortol | Alpha-Cortol with a 20b-OH group; the 5b enantiomer of beta-allocortol, found in urine. (05 Mar 2000) |
| beta-cortolone | Alpha-Cortolone with a 20b-OH group; the 5b enantiomer of beta-allocortolone, found in urine. (05 Mar 2000) |
| beta-cyclohexenyl carotenoid epoxidase | <enzyme> Isolated from the pepper capsicum annuum; genbank x91491 Registry number: EC 1.14.14.- Synonym: beta-chc epoxidase (26 Jun 1999) |
| beta-cyclopiazonate dehydrogenase | <enzyme> Catalyses the conversion of beta-cyclopiazonic acid to alpha-cyclopiazonic acid, forming a 5-ring fused system connecting the pyrrole and indole rings; minor descriptor (75-83); on-line and index medicus search oxidoreductases (75-83) Registry number: EC 1.3.99.9 Synonym: beta-cyclopiazonate oxidocyclase (26 Jun 1999) |
| 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) |
| 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) |