title: Biosynthesis of riboflavin. Characterization of the product of the deaminase.
abstract: The 2'5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5'-phosphate deaminase was partially purified from cell extracts of Candida guilliermondii ATCC 9058. The enzyme requires Mg2+ for activity. Maximal activity was observed at pH 7,3. The enzyme converts its substrate, 2,5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5'-phosphate, to 2,5-diamino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione 5'-phosphate. This labile compound was treated with diacetyl and the resulting 6,7-dimethyl-8-ribityllumazine 5'-phosphate was identified by comparison with a synthetic sample.
mesh_terms: D000619:Aminohydrolases / Q000302:isolation & purification / Q000378:metabolism*; D002175:Candida / Q000201:enzymology*; D007700:Kinetics; D012256:Riboflavin / Q000096:biosynthesis*; D013050:Spectrometry, Fluorescence
chemical_list: C033326:2,5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5'-phosphate deaminase; D000619:Aminohydrolases; D012256:Riboflavin