title: Asymmetric reduction of diketones by two Gluconobacter oxydans oxidoreductases.
abstract: Two genes encoding recombinant cytosolic oxidoreductases from Gluconobacter oxydans, gox0313 and gox0646, were heterologously expressed in Escherichia coli and the resulting proteins were purified and characterized. GOX0313 was identified as a medium-chain alcohol dehydrogenase, whereas GOX0646 was classified as a ketocarbonyl reductase. GOX0313 had a broad substrate spectrum and oxidized various primary alcohols. However, GOX0313 had a preference for substrate reduction, reducing many aldehydes and α-diketones. In contrast, GOX0646 had a narrow substrate spectrum and reduced α-diketones, preferring short-chain ketocarbonyls. Both enzymes regio- and stereospecifically reduced α-diketones to the corresponding (S)-hydroxy ketone, as shown by NMR. These products are difficult to produce chemically, requiring complicated protecting group chemistry. Furthermore, hydroxy ketones find industrial application in the production of pheromones, fragrances, flavors, and pharmaceuticals. Hence, these enzymes are interesting biocatalysts for the production of enantiomerically pure building blocks that are difficult to prepare chemically.
authors.affiliation: Department of Biology, Missouri State University, 901 South National Avenue, Springfield, MO 65897, USA. PSchweiger@MissouriState.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Schweiger
authors.forename: Harald
authors.initials: H
authors.lastname: Gross
authors.forename: Jessica
authors.initials: J
authors.lastname: Zeiser
authors.forename: Uwe
authors.initials: U
authors.lastname: Deppenmeier
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001711:Biotransformation; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D020600:Gluconobacter oxydans / Q000201:enzymology* / Q000235:genetics; D007659:Ketones / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D007659:Ketones; D000429:Alcohol Oxidoreductases; D000426:Alcohol Dehydrogenase