title: Covalent immobilization of β-1,4-glucosidase from Agaricus arvensis onto functionalized silicon oxide nanoparticles.
abstract: An efficient β-1,4-glucosidase (BGL) secreting strain, Agaricus arvensis, was isolated and identified. The relative molecular weight of the purified A. arvensis BGL was 98 kDa, as determined by sodium dodecylsulfate polyacrylamide gel electrophoresis, or 780 kDa by size exclusion chromatography, indicating that the enzyme is an octamer. Using a crude enzyme preparation, A. arvensis BGL was covalently immobilized onto functionalized silicon oxide nanoparticles with an immobilization efficiency of 158%. The apparent V (max) (k (cat)) values of free and immobilized BGL under standard assay conditions were 3,028 U mg protein(-1) (4,945 s(-1)) and 3,347 U mg protein(-1) (5,466 s(-1)), respectively. The immobilized BGL showed a higher optimum temperature and improved thermostability as compared to the free enzyme. The half-life at 65 °C showed a 288-fold improvement over the free BGL. After 25 cycles, the immobilized enzyme still retained 95% of the original activity, thus demonstrating its prospects for commercial applications. High specific activity, high immobilization efficiency, improved stability, and reusability of A. arvensis BGL make this enzyme of potential interest in a number of industrial applications.
authors.affiliation: Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul, South Korea, 143-701.
authors.forename: Raushan Kumar
authors.initials: RK
authors.lastname: Singh
authors.forename: Ye-Wang
authors.initials: YW
authors.lastname: Zhang
authors.forename: Ngoc-Phuong-Thao
authors.initials: NP
authors.lastname: Nguyen
authors.forename: Marimuthu
authors.initials: M
authors.lastname: Jeya
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
mesh_terms: D000364:Agaricus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000302:isolation & purification; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D012988:Soil Microbiology; D001617:beta-Glucosidase / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D012822:Silicon Dioxide; D001617:beta-Glucosidase