title: An efficient immobilizing technique of penicillin acylase with combining mesocellular silica foams support and p-benzoquinone cross linker.
abstract: To improve the performance of covalently immobilized penicillin acylase (PA), the immobilization was carried out in mesocellular silica foams (MCFs) using p-benzoquinone as cross linker. The characterizations of the immobilized enzyme were studied carefully. The results showed that the relative activity of the immobilized PA was increased to 145% of that of free enzyme. The activity was 3.7 folds of that of PA on the silica nanoparticles. The enzyme in MCFs presented a turnover equal to that of free enzyme. It was also found that the optimum pH of the immobilized PA shifted to pH 7.5 and the optimum reaction temperature rose from 45 to 50 degrees C. Furthermore, the stability of PA was ameliorated greatly after immobilization. Fourier transform infrared spectroscopy showed no major secondary structural change for PA confined in MCFs. The proposed covalent immobilizing technique would rank among the potential strategies for efficient immobilization of PA.
authors.affiliation: National Engineering Research Center for Biotechnology, College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, No.5 Xinmofan Road, Nanjing, People's Republic of China.
authors.forename: Anming
authors.initials: A
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Shemin
authors.initials: S
authors.lastname: Zhu
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Du
authors.forename: Shubao
authors.initials: S
authors.lastname: Shen
mesh_terms: D000327:Adsorption; D016227:Benzoquinones / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D010399:Penicillin Amidase / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D016227:Benzoquinones; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D005740:Gases; C004532:quinone; D012822:Silicon Dioxide; D010399:Penicillin Amidase