title: Characterization of an efficient catalytic and organic solvent-tolerant azoreductase toward methyl red from Shewanella oneidensis MR-1.
abstract: The acyl carrier protein (ACP) phosphodiesterase gene (SO 4396) of Shewanella oneidensis MR-1 which was analyzed to have azoreductase activity was heterologously expressed in Escherichia coli. The ACP phosphodiesterase was found to reach maximum enzyme velocity 220.59 U/mg, named azoreductase in this study. The azoreductase had highest specific activity (153.16 U/mg) at pH 6.5, which showed a preference for nicotinamide adenine dinucleotide (NADH) as electron donor. The phylogenetic tree analysis indicated that the azoreductase had preference for NADH and dependence for flavin mononucleotide (FMN). However, the azoreductase from S. oneidensis MR-1 still had high enzyme activity in the absence of FMN. The Mg(2+) had a positive influence on the enzyme activity with 25 mM concentration, whereas Cr(3+), Cd(2+) usually had significantly negative effect on enzyme activity. The purified azoreductase retained nearly 100 % activity after incubating in 30 % dimethyl sulfoxide (DMSO), 30 % acetone, 30 % methanol, 20 % ethanol, 20 % isopropanol, and 10 % propanol.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
authors.forename: Yuyi
authors.initials: Y
authors.lastname: Yang
authors.forename: Liling
authors.initials: L
authors.lastname: Lu
authors.forename: Fen
authors.initials: F
authors.lastname: Gao
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005486:Flavin Mononucleotide / Q000378:metabolism; D007477:Ions / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017385:Sequence Homology; D020592:Shewanella / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics*; D012997:Solvents / Q000378:metabolism; D013501:Surface-Active Agents / Q000378:metabolism; D013696:Temperature
chemical_list: D007477:Ions; D019216:Metals, Heavy; D012997:Solvents; D013501:Surface-Active Agents; D009243:NAD; D009249:NADP; D005486:Flavin Mononucleotide; D009247:NADH, NADPH Oxidoreductases; C021584:methyl red azoreductase; D010727:Phosphoric Diester Hydrolases; C018754:(acyl-carrier-protein) phosphodiesterase