title: Immobilization of Cyclooxygenase-2 on Silica Gel Microspheres: Optimization and Characterization.
abstract: In this study, immobilized COX-2 was successfully constructed through glutaraldehyde-mediated covalent coupling on functional silica gel microspheres. The optimum conditions, properties, and morphological characteristics of the immobilized COX-2 were investigated. The optimal immobilization process was as follows: about 0.02 g of aminated silica gel microspheres was activated by 0.25% GA solution for 6 h and mixed with 5 U of free recombinant COX-2 solution. Then, the mixture was shaken for 8 h at 20 °C. Results showed that the immobilized COX-2 produced by this method exhibited excellent biocatalytic activity, equivalent to that of free COX-2 under the test conditions employed. The best biocatalytic activity of immobilized COX-2 appeared at pH 8.0 and still maintained at about 84% (RSD < 7.39%, n = 3) at pH 10.0. For temperature tolerance, immobilized COX-2 exhibited its maximum biocatalytic activity at 40 °C and about 68% (RSD < 6.99%, n = 3) of the activity was maintained at 60 °C. The immobilized COX-2 retained over 85% (RSD < 7.26%, n = 3) of its initial biocatalytic activity after five cycles, and after 10 days storage, the catalytic activity of immobilized COX-2 still maintained at about 95% (RSD < 3.08%, n = 3). These characteristics ensured the convenient use of the immobilized COX-2 and reduced its production cost.
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. srdwjm@sina.com.|Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. srdwjm@sina.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. jhchen@fio.org.cn.
authors.forename: Junhui
authors.initials: J
authors.lastname: Chen
authors.affiliation: Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. wangyanlong92@163.com.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. lizhaoyong2056@126.com.
authors.forename: Zhaoyong
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. lixg@ouc.edu.cn.
authors.forename: Xianguo
authors.initials: X
authors.lastname: Li
authors.affiliation: Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. csun@fio.org.cn.
authors.forename: Chengjun
authors.initials: C
authors.lastname: Sun
authors.affiliation: Research Center for Marine Ecology, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China. zhengli@fio.org.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
mesh_terms: D055162:Biocatalysis; D051546:Cyclooxygenase 2 / Q000737:chemistry* / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D008863:Microspheres; D058428:Silica Gel / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics
chemical_list: D004800:Enzymes, Immobilized; D058428:Silica Gel; D051546:Cyclooxygenase 2
keywords: aminated silica gel; cross linking; cyclooxyenase 2; immobilized enzyme