title: Thermostable N-carbamoyl-D-amino acid amidohydrolase: screening, purification and characterization.
abstract: A thermostable N-carbamoyl-D-amino acid amidohydrolase was found in the cells of newly isolated bacterium. Blastobacter sp. A17p-4. The bacterium also showed D-specific hydantoinase activity. The N-carbamoyl-D-amino acid amidohydrolase activity of the cells exhibited a temperature optimum at 50-55 degrees C, and was stable up to 50 degrees C. The N-carbamoyl-D-amino acid amidohydrolase of Blastobacter sp. A17p-4 was purified to homogeneity and characterized. It has a relative molecular weight of about 120,000 and consists of three identical subunits with a relative molecular weight of about 40,000. N-Carbamoyl-D-amino acids having hydrophobic groups served as good substrates for the enzyme. It has been suggested that D-amino acid production from DL-5-substituted hydantoin involves the action of a series of enzymes involved in pyrimidine degradation, namely amide-ring opening enzyme, dihydropyrimidinase, and N-carbamoylamide hydrolyzing enzyme, beta-ureidopropionase. However, the purified enzyme did not hydrolyze beta-ureidopropionate; suggesting that the N-carbamoyl-D-amino acid amidohydrolase coexisting with D-specific hydantoinase, probably dihydropyrimidinase, in Blastobacter sp. A17p-4 is different from beta-ureidopropionase.
authors.affiliation: Department of Agricultural Chemistry, Kyoto University, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Ogawa
authors.forename: M C
authors.initials: MC
authors.lastname: Chung
authors.forename: S
authors.initials: S
authors.lastname: Hida
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: S
authors.initials: S
authors.lastname: Shimizu
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006090:Gram-Negative Bacteria / Q000201:enzymology*; D006358:Hot Temperature; D008969:Molecular Sequence Data
chemical_list: D000581:Amidohydrolases; C080477:N-carbamoyl-D-amino acid amidohydrolase