| thiaminase | 1. An enzyme present in raw fish that destroys thiamin and may produce thiamin deficiency in animals on a diet largely composed of raw fish. 2. A hydrolase cleaving thiamin into a pyrimidine moiety (i.e., 2-methyl-4-amino-5-hydroxymethylpyrimidine) and a thiazole moiety (i.e., 4-methyl-5-(2'-hydroxyethyl)-thiazole); the pyrimidine moiety may appear in the urine as pyramin. Synonym: thiaminase II. (05 Mar 2000) |
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| thiaminase I | <enzyme> An enzyme catalyzing transfer of a pyridine or other bases into the position of the pyrimidine in thiamin; e.g., thiamin reacting with pyridine produces heteropyrithiamin and 4-methyl-5-(2'-hydroxyethyl)-thiazole. Synonym: pyrimidine transferase, thiaminase I. (05 Mar 2000) |
| thiaminase II | 1. An enzyme present in raw fish that destroys thiamin and may produce thiamin deficiency in animals on a diet largely composed of raw fish. 2. A hydrolase cleaving thiamin into a pyrimidine moiety (i.e., 2-methyl-4-amino-5-hydroxymethylpyrimidine) and a thiazole moiety (i.e., 4-methyl-5-(2'-hydroxyethyl)-thiazole); the pyrimidine moiety may appear in the urine as pyramin. Synonym: thiaminase II. (05 Mar 2000) |