Poly(hydroxyethyl methacrylate‐co‐glycidyl methacrylate) reactive membrane utilised for cholesterol oxidase immobilisation |
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Authors: | Sinan Akgl Gülay Bayramolu Yasemin Kacar Adil Denizli M Yakup Arca |
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Affiliation: | Sinan Akgöl,Gülay Bayramo?lu,Yasemin Kacar,Adil Denizli,M Yakup Ar?ca |
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Abstract: | Poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) p(HEMA–GMA) membrane was prepared by UV‐initiated photopolymerisation of 2‐hydroxyethyl methacrylate (HEMA) and glycidyl methacrylate (GMA) in the presence of an initiator, azobisisobutyronitrile (AIBN). Cholesterol oxidase was immobilised directly on the membrane by forming covalent bonds between its amino groups and the epoxide groups of the membrane. An average of 53 µg of enzyme was immobilised per cm2 of membrane, and the bound enzyme retained about 67% of its initial activity. Immobilisation improved the pH stability of the enzyme as well as its temperature stability. The optimum temperature was 5 °C higher than that of the free enzyme and was significantly broader. The thermal inactivation rate constants for free and immobilised preparations at 70 °C were calculated as ki (free) 1.06 × 10?1 min?1 and ki (imm) 2.68 × 10?2 min?1, respectively. The immobilised enzyme activity was found to be quite stable in the repeated experiments. © 2002 Society of Chemical Industry |
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Keywords: | pHEMA membrane epoxy support immobilization covalent attachment cholesterol oxidase |
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