title: Enhanced hydantoinase and N-carbamoylase activity on immobilisation of Agrobacterium tumefaciens.
abstract: Cell extracts of Agrobacterium tumefaciens, immobilised in calcium alginate beads, had a 7-fold increase in N-carbamoylase (N-carbamylamino acid amidohydrolase E.C. 3.5.1) activity on reaction with N-carbamylglycine. The hydantoinase (dihydropyrimidinase E.C. 3.5.2.2) and N-carbamoylase activities remained stable over 4 weeks storage at 4 degrees C relative to the non-immobilised enzymes, with the hydantoinase activity showing a 5-fold increase in activity relative to the non-immobilised hydantoinase. The pH optima of the immobilised hydantoinase and N-carbamoylase enzymes decreased to pH 7 and pH 8, respectively. The temperature optimum remained at 40 degrees C for the N-carbamoylase enzyme while the hydantoinase activity was optimal at 50 degrees C.
authors.affiliation: Department of Biochemistry and Microbiology, Rhodes University P.O. Box 94, Grahamstown, 6140, South Africa.
authors.forename: Ingrid M
authors.initials: IM
authors.lastname: Foster
authors.forename: Rosemary D
authors.initials: RD
authors.lastname: Dorrington
authors.forename: Stephanie G
authors.initials: SG
authors.lastname: Burton
mesh_terms: D016960:Agrobacterium tumefaciens / Q000737:chemistry / Q000145:classification / Q000201:enzymology*; D000464:Alginates; D000581:Amidohydrolases / Q000096:biosynthesis* / Q000737:chemistry; D002457:Cell Extracts / Q000737:chemistry / Q000145:classification; D018914:Cells, Immobilized / Q000737:chemistry / Q000145:classification / Q000201:enzymology; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D011786:Quality Control; D013696:Temperature
chemical_list: D000464:Alginates; D002457:Cell Extracts; D004800:Enzymes, Immobilized; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D000581:Amidohydrolases; C080477:N-carbamoyl-D-amino acid amidohydrolase; C020047:dihydropyrimidinase