| histidine decarboxylase | <enzyme> An enzyme that catalyses the decarboxylation of histidine to histamine and carbon dioxide. It requires pyridoxal phosphate in animal tissues, but not in microorganisms. Chemical name: L-Histidine carboxy-lyase Registry number: EC 4.1.1.22 (12 Dec 1998) |
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| histidine N-acetyltransferase | <enzyme> Synthesises nalpha-acetyl-l-histidine from l-histidine and acetylcoenzyme a Registry number: EC 2.3.1.33 Synonym: acetyl-CoA - l-histidine n-acetyltransferase, histidine acetyltransferase, coasac - l-histidine n-acetyltransferase, n-acetylhistidine synthetase (26 Jun 1999) |
| histidine permease | <chemical> Hisp, hism and hisq are membrane proteins found in histidine permease (the hisqmp2 complex); also contains the histidine-binding protein hisj Chemical name: permease, histidine Synonym: hisp protein, hism protein, hisq protein, hutm gene product, ee57d gene product (26 Jun 1999) |
| histidine-trna ligase | <enzyme> An enzyme that activates histidine with its specific transfer RNA. Chemical name: L-Histidine:tRNA(His) ligase (AMP-forming) Registry number: EC 6.1.1.21 (12 Dec 1998) |
| histidino | The radical of histidine produced by removal of a hydrogen from a nitrogen atom; prefixed by Na, Nτ, or Nπ. (05 Mar 2000) |
| histidinol | <chemical> Beta-amino-1h-imidazole-4-propanol. The penultimate step in the pathway of histidine biosynthesis. Oxidation of the alcohol group on the side chain gives the acid group forming histidine. Histidinol has also been used as an inhibitor of protein synthesis. Chemical name: 1H-Imidazole-4-propanol, beta-amino- (12 Dec 1998) |
| histidinol-phosphatase | <enzyme> An enzyme that catalyses the hydrolysis of histidinol-phosphate to histidinol. One of the regulatory enzymes in histidine biosynthesis. Chemical name: L-Histidinol-phosphate phosphohydrolase Registry number: EC 3.1.3.15 (12 Dec 1998) |
| histidinuria | Excretion of considerable amounts of histidine in the urine; frequently observed in later months of pregnancy, and in histidinaemia. (05 Mar 2000) |
| histidyl | The acyl radical of histidine. (05 Mar 2000) |
| histio- | Tissue, especially connective tissue. Origin: G. Histion, web (tissue) (05 Mar 2000) |
| histioblast | A tissue-forming cell. Synonym: histoblast. Origin: histio-+ G. Blastos, germ (05 Mar 2000) |
| histiocyte | <pathology> Long lived resident macrophage found within tissues. (11 Jan 1998) |
| histiocytic | Relating to or involving histiocytes (macrophages). (09 Oct 1997) |
| histiocytic disorders, malignant | Distinctive neoplastic disorders of histiocytes. Included are acute monocytic leukaemias, malignant histiocytosis (histiocytosis, malignant), and true histiocytic lymphomas. (12 Dec 1998) |
| histiocytic lymphoma | <tumour> A malignant tumour of reticular tissue composed predominantly of neoplastic histiocytes. See: large cell lymphoma. (05 Mar 2000) |