The improvement of chloroperoxidase activities in the presence of ammonium salts and cationic surfactants |
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| Authors: | Xuejiao Ru Jinyue Wu Huan Guo Yucheng Jiang Mancheng Hu Quanguo Zhai Shuni Li |
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| Affiliation: | 1. School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an, Shaanxi 710062, P.R. China;2. Key Laboratory of Macromolecular Science of Shaanxi Province, Shaanxi Normal University, Xi'an, Shaanxi 710062, P.R. China |
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| Abstract: | The catalytic activities of chloroperoxidase (CPO) including halogenation, oxidation, and peroxidation were investigated in the presence of ammonium salts: tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), tetrapropylammonium bromide (TPABr), tetrabutylammonium bromide (TBABr), and cationic surfactants: dodecyltrimethylammonium bromide (DTABr) and cetyltrimethylammonium bromide (CTABr). All the mentioned activities were promoted in most cases. The highest modified activity (ABTS peroxidation) was 18.16 times higher in the presence of TMABr than that in pure buffer. The activity enhancement was strongly dependent on the concentration and the hydrophobic chain length of additives, and the structure of substrates. The kinetic parameters showed that the activation was mainly attributed to an increase in kcat due probably to a catalytically favorable conformation of CPO induced by the additives. Moreover, a lower Km and higher ratio of kcat/Km (specificity constant) was obtained, indicating that both the affinity and specificity of CPO to substrates were improved in the presence of additives. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 |
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| Keywords: | chloroperoxidase ammonium salts cationic surfactants improvement of activities |
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