title: Characterization of Styrene Oxide Isomerase, a Key Enzyme of Styrene and Styrene Oxide Metabolism in Corynehacterium sp.
abstract: Styrene oxide isomerase (SOI) [EC 5.3.99.7], most probably located in the cell wall, was partially purified from Coiynebacterium sp. AC-5 cells grown in a styrene gas atmospheres. The enzyme catalyzed the isomerization reaction to give phenylacetaldehyde, but did not catalyze its reverse reaction. The optimum pH of the reaction was around 7.0, and the enzyme was unstable below pH 6.0. The Km toward styrene oxide was very low (7.7 × 10(-5) m), indicating its high affinity for styrene oxide. The enzyme showed strict substrate specificity, and epoxide compounds other than styrene oxide did not serve as substrates. (S)-Styrene oxide was preferentially converted by the enzyme, compared with the (R)-isomer. The possible application of SOI as a biocatalyst is also discussed.
authors.affiliation: b Biotechnology Research Center, Toyama Prefectural University , 5180 Kurokawa Kosugi, Toyama 939-03 , Japan.
authors.forename: N
authors.initials: N
authors.lastname: Itch
authors.affiliation: a Department of Applied Chemistry and Biotechnology, Faculty of Engineering , Fukui University , Bunkyo 3-9-1, Fukui 910 , Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: a Department of Applied Chemistry and Biotechnology, Faculty of Engineering , Fukui University , Bunkyo 3-9-1, Fukui 910 , Japan.
authors.forename: K
authors.initials: K
authors.lastname: Okada
authors.affiliation: a Department of Applied Chemistry and Biotechnology, Faculty of Engineering , Fukui University , Bunkyo 3-9-1, Fukui 910 , Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ito
authors.affiliation: a Department of Applied Chemistry and Biotechnology, Faculty of Engineering , Fukui University , Bunkyo 3-9-1, Fukui 910 , Japan.
authors.forename: N
authors.initials: N
authors.lastname: Mizuguchi
keywords: Corynehacterium sp.; metabolism; styrene; styrene oxide; styrene oxide isomerase