title: Biotransformation of amides to acids using a co-cross-linked enzyme aggregate of Rhodococcus erythropolis amidase.
abstract: Rhodococcus erythropolis amidase was expressed in Escherichia coli cells. The crude amidase in the cell-free extract was immobilized using the cross-linked enzyme aggregate (CLEA) method. The crude amidase was mixed with bovine serum albumin and then precipitated with ammonium sulfate. The resultant precipitant was subsequently cross-linked with glutaraldehyde. Scanning electron microscopy revealed that this co-CLEA had a ball-like shape of a diameter of approximately 1 micronm. This co-CLEA evidenced hydrolytic activity toward a variety of amide substrates. The amidase co-CLEA evidenced an optimum temperature of 60 degrees and an optimum pH of 8.0, results that were similar to those of the soluble amidase. The reaction stability of the co-CLEA was increased. That is, it was stable up to 50 degrees and in a pH range of 5.0-12.0. Additionally, the co-CLEA could be recovered by centrifugation, and retained 96% activity after 3 repeated cycles. This amidase co-CLEA may prove useful as a substitute for soluble amidase as a biocatalyst in the pharmaceutical and chemical industries.
authors.affiliation: Division of Biotechnology, The Catholic University of Korea, Bucheon 420-743, Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Park
authors.forename: Ki-Nam
authors.initials: KN
authors.lastname: Uhm
authors.forename: Hyung Kwoun
authors.initials: HK
authors.lastname: Kim
mesh_terms: D000143:Acids / Q000378:metabolism*; D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000588:Amines / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001711:Biotransformation; D003432:Cross-Linking Reagents / Q000737:chemistry; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005976:Glutaral / Q000737:chemistry; D012240:Rhodococcus / Q000201:enzymology* / Q000235:genetics
chemical_list: D000143:Acids; D000588:Amines; D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D000581:Amidohydrolases; C019665:amidase; D005976:Glutaral