title: Chemically modified Sepharose as support for the immobilization of cholesterol oxidase.
abstract: Because the cholesterol oxidase from Brevibacterium sp. M201008 was not as stable as the free enzyme form, it had been covalently immobilized onto chemically modified Sepharose particles via N-ethyl-N'-3-dimethylaminopropyl carbodiimide. The optimum immobilization conditions were determined, and the immobilized enzyme activity obtained was 12.01 U/g Sepharose-ethylenediamine. The immobilization of the enzyme was characterized by Fourier transform infrared spectroscopy. The immobilized enzyme exhibited the maximal activity at 35°C and pH 7.5, which was unchanged compared with the free form. After being repeatedly used 20 times, the immobilized enzyme retained more than 40.43% of its original activity. The immobilized enzyme showed better operational stability, including wider thermal and pH ranges, and retained 62.87% activity after 20 days of storage at 4°C, which was longer than the free enzyme.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, PR China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Yang
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Xin
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Yuran
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wu
authors.initials: W
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D001951:Brevibacterium / Q000737:chemistry / Q000201:enzymology*; D002789:Cholesterol Oxidase / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012685:Sepharose / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D012685:Sepharose; D002789:Cholesterol Oxidase