title: Properties of diacetyl (acetoin) reductase from Bacillus stearothermophilus.
abstract: The cells of Bacillus stearothermophilus contain an NADH-dependent diacetyl (acetoin) reductase. The enzyme was easily purified to homogeneity, partially characterised, and found to be composed of two subunits with the same molecular weight. In the presence of NADH, it catalyses the stereospecific reduction of diacetyl first to (3S)-acetoin and then to (2S,3S)-butanediol; in the presence of NAD+, it catalyses the oxidation of (2S,3S)- and meso-butanediol, respectively, to (3S)-acetoin and to (3R)-acetoin, but is unable to oxidise these compounds to diacetyl. The enzyme is also able to catalyse redox reactions involving some endo-bicyclic octen- and heptenols and the related ketones, and its use is suggested also for the recycling of NAD+ and NADH in enzymatic redox reactions useful in organic syntheses.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Ferrara, Italy.
authors.forename: P P
authors.initials: PP
authors.lastname: Giovannini
authors.forename: A
authors.initials: A
authors.lastname: Medici
authors.forename: C M
authors.initials: CM
authors.lastname: Bergamini
authors.forename: M
authors.initials: M
authors.lastname: Rippa
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D002849:Chromatography, Gas; D004795:Enzyme Stability; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D007700:Kinetics; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000429:Alcohol Oxidoreductases; C019801:butanediol dehydrogenase