title: Purification and characterization of monovalent cation-activated levodione reductase from Corynebacterium aquaticum M-13.
abstract: (6R)-2,2,6-Trimethyl-1,4-cyclohexanedione (levodione) reductase was isolated from a cell extract of the soil isolate Corynebacterium aquaticum M-13. This enzyme catalyzed regio- and stereoselective reduction of levodione to (4R,6R)-4-hydroxy-2,2, 6-trimethylcyclohexanone (actinol). The relative molecular mass of the enzyme was estimated to be 142,000 Da by high-performance gel permeation chromatography and 36,000 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme required NAD(+) or NADH as a cofactor, and it catalyzed reversible oxidoreduction between actinol and levodione. The enzyme was highly activated by monovalent cations, such as K(+), Na(+), and NH(4)(+). The NH(2)-terminal and partial amino acid sequences of the enzyme showed that it belongs to the short-chain alcohol dehydrogenase/reductase family. This is the first report of levodione reductase.
authors.affiliation: Department of Bioscience, Fukui Prefectural University, 4-1-1 Kenjyojima, Fukui 910-1195, Japan. masaru@fpu.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Wada
authors.forename: A
authors.initials: A
authors.lastname: Yoshizumi
authors.forename: S
authors.initials: S
authors.lastname: Nakamori
authors.forename: S
authors.initials: S
authors.lastname: Shimizu
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D003352:Corynebacterium / Q000201:enzymology*; D003512:Cyclohexanones / Q000378:metabolism*; D004789:Enzyme Activation; D004795:Enzyme Stability; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010088:Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D003512:Cyclohexanones; D012964:Sodium; D010088:Oxidoreductases; D011188:Potassium