Effect of Immobilization on the Activity of Rat Hepatic-Microsomal Cytochrome P450 Enzymes

Fernandezsalguero, P. and Gutierrezmerino, C. and Bunch, A.W. (1993) Effect of Immobilization on the Activity of Rat Hepatic-Microsomal Cytochrome P450 Enzymes. Enzyme and Microbial Technology, 15 (2). pp. 100-104. ISSN 0141-0229. (The full text of this publication is not available from this repository)

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Abstract

Cytochrome P450 enzyme preparations were obtained from phenobarbital-treated rats.'On immobilization in Romicon PM 10 polysulfone anisotropic hollow fibers, 20-25% of the original activity remained. The immobilization procedure did not significantly alter the K(m) of the preparations when 7-ethoxycoumarin was the substrate. Coimmobilization of the preparations with glucose-6-phosphate dehydrogenase allowed cofactor recycling to take place but resulted in an apparent drop in the value for the K(m). The V(max) of immobilized preparations with or without cofactor recycling was about 25% of that observed with the nonimmobilized preparations. The flow rate through the reactors greatly affected the time at which product was detected in the effluent from the reactor and the amount of 7-hydroxycoumarin produced. It is suggested that this reflects alternative fates of the NADPH cofactor when residence times in the reactor are lengthened. Increasing the amounts of protein immobilized increased the K(m) and decreased the V(max) values in comparison to the free enzyme. Immobilization increased the stability of preparations with respect to ionic strength and storage. Little effect was noted with regard to changes in temperature stability or pH optima of immobilized preparations.

Item Type: Article
Subjects: Q Science > QR Microbiology
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: M. Nasiriavanaki
Date Deposited: 09 Aug 2009 18:00
Last Modified: 09 Aug 2009 18:00
Resource URI: http://kar.kent.ac.uk/id/eprint/22089 (The current URI for this page, for reference purposes)
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