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    Application of natural kaolin as support for the immobilization of catalase from bovine liver
    (Asian Publication Corporation, 2006) Savran, Ali; Alkan, Salih; Demir, Halit; Ceylan, Hasan; Ceylan, Hasan
    Catalase from bovine liver was immobilized on to natural kaolin by physical adsorption method. About 80% of the protein content was immobilized on to support. The activities of immobilized catalase were determined in the reaction mixture containing substrate hydrogen peroxide and free catalase. The effects of reaction temperature, thermostability, stability in organic solvent, leaching and storage studies of immobilized catalase were investigated. Kaolin-immobilized catalase exhibited activities higher by four folds than free catalase after thermal stability test at 70ºC. Immobilized catalase was found to be stable in hexane at room temperature up to 12 d and also showed higher stability than free catalase in the storage study. Leaching studies showed that the immobilized catalase remained fully active even after being washed by 20 mL of solvent. The experimental results showed that physical adsorption is suitable for the attachment of enzyme on to kaolin.
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    Application of natural kaolin as support for the immobilization of catalase from bovine liver
    (Asian Publication Corporation, 2006) Savran, Ali; Alkan, Salih; Demir, Halit; Ceylan, Hasan; Ceylan, Hasan
    Catalase from bovine liver was immobilized on to natural kaolin by physical adsorption method. About 80% of the protein content was immobilized on to support. The activities of immobilized catalase were determined in the reaction mixture containing substrate hydrogen peroxide and free catalase. The effects of reaction temperature, thermostability, stability in organic solvent, leaching and storage studies of immobilized catalase were investigated. Kaolin-immobilized catalase exhibited activities higher by four folds than free catalase after thermal stability test at 70ºC. Immobilized catalase was found to be stable in hexane at room temperature up to 12 d and also showed higher stability than free catalase in the storage study. Leaching studies showed that the immobilized catalase remained fully active even after being washed by 20 mL of solvent. The experimental results showed that physical adsorption is suitable for the attachment of enzyme on to kaolin.
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    Effects of some drugs on enzyme activity of catalase from bovine liver
    (Asian Publication Corporation, 2006) Alkan, Salih; Savran, Ali; Demir, Halit; Ceylan, Hasan; Ceylan, Hasan
    The effects of gentamicin sulphate, acetyl salicylic acid, ampicillin sodium, paracetamol, potassium penicillin and augmentin were investigated on the in-vitro enzyme activity of catalase. Catalase (CAT:EC1.11.1.6) was purified from bovine liver by a simple and rapid method. The purification process was done by 2´,5´-ADP sepharose 4B affinity chromatography. Although the purified enzyme showed a tetrameric band on sodium dodecyl sulphate polyacryilamide gel electrophrosis but bovine liver showed a one band. The enzyme activity was measured spectrophotometrically at 240 nm, according to the method of Aebi. From these six drugs, paracetamol, potassium penicillin and augmentin inhibited the activity of the purified enzyme; gentamicin sulphate, acetyl salicylic acid and ampicillin sodium showed little effect on the enzyme activity. The I50 values for these three drugs were as 4.6, 0.35 and 0.49 mM, respectively. The Ki constants were 20, 25 and 25 mM, respectively and they were competitive inhibitors.