Improving the Cytochrome P450 Enzyme System for Electrode-Driven Biocatalysis of Styrene Epoxidation

Published

July 1, 2000

Author(s)

M P. Mayhew, Vytautas Reipa, Marcia J. Holden, V L. Vilker

Abstract

Cytochrome P450 enzymes catalyze a vast array of oxidative and reductive biotransformations that are potentially useful for industrial and pharmaceutical syntheses. Factors such as cofactor utilization and slow reaction rates for non-natural substrates limit their large-scale usefulness. This paper reports several improvements that make the cytochrome P450cam enzyme system more practical for the epoxidation of styrene. NADH coupling was increased from 14% to 54%, and product turnover rate was increased from 8 min^-1 to 70 min ^-1 by introducing the Y96F mutation to P450cam. Styrene and styrene and styrene oxide mass balance determinations showed different product profiles at low and high styrene conversion levels. For styrene conversion less than about 25%, the stoichiometry between styrene consumption and styrene oxide formation was 1:1. At high styrene conversion, a second doubly oxidized product, α-hydroxyacetophenone product was suppressed in reactions where styrene was present at saturating concentrations. Finally, styrene epoxidation was carried out in an electro-enzymatic reactor. In this scheme, the costly NADH cofactor and one of the three proteins (putidaredoxin reductase are eliminated from the Y96F P450cam enzyme system.

Citation

Biotechnology Progress

Volume

16

Issue

4

Pub Type

Journals

Keywords

biocatalysis, Cytochrome P450, electroenzymology, styrene oxide

Citation

Mayhew, M. , Reipa, V. , Holden, M. and Vilker, V. (2000), Improving the Cytochrome P450 Enzyme System for Electrode-Driven Biocatalysis of Styrene Epoxidation, Biotechnology Progress (Accessed April 19, 2024)