Stereoselective Reduction of Carbonyl Compounds with Actinomycete: Purification and Characterization of Three α-Keto Ester Reductases fromStreptomyces avermitilis

2008 ◽  
Vol 72 (12) ◽  
pp. 3249-3257 ◽  
Author(s):  
Kohji ISHIHARA ◽  
Chiaki KATO ◽  
Hitomi YAMAGUCHI ◽  
Rieko IWAI ◽  
Momoko YOSHIDA ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Purification And Characterization ◽  
Stereoselective Reduction ◽  
Keto Ester

Purification and characterization of rat liver enzyme catalyzing stereoselective reduction of acetylpyridines

Chirality ◽  
2005 ◽  
Vol 17 (8) ◽  
pp. 494-500 ◽  
Author(s):  
Koji Uwai ◽  
Noboru Konno ◽  
Shigeyuki Kitamura ◽  
Shigeru Ohta ◽  
Mitsuhiro Takeshita
Keyword(s):  
Liver Enzyme ◽  
Rat Liver ◽  
Purification And Characterization ◽  
Stereoselective Reduction

scholarly journals Purification and characterization of a novel dimeric 20 α-hydroxysteroid dehydrogenase from Tetrahymena pyriformis

1994 ◽  
Vol 297 (1) ◽  
pp. 195-200 ◽  
Author(s):  
A Inazu ◽  
K Sato ◽  
T Nakayama ◽  
Y Deyashiki ◽  
A Hara ◽  
...  
Keyword(s):  
Hydroxy Group ◽  
Carbonyl Compounds ◽  
Specific Activity ◽  
Reductase Activity ◽  
Tetrahymena Pyriformis ◽  
Hydroxysteroid Dehydrogenase ◽  
Purification And Characterization ◽  
Reductase Inhibitors ◽  
Hydroxy Groups

Tetrahymena pyriformis was found to exhibit high NADPH-dependent 20-oxosteroid reductase activity that converted 17 alpha-hydroxyprogesterone into 17 alpha,20 alpha-dihydroxypregn-4-en-3-one. The enzyme was purified 400-fold from the cytosolic fraction. The purified enzyme with a specific activity of 6.4 mumol/min per mg of protein had an isoelectric point of 4.9 and M(r) of 68,000, and was composed of two subunits of equal size. The N-terminal sequence was determined to be LAKTVPLNDGTNFPIFGG. The enzyme reduced pregnanes and pregnanes possessing a 17 alpha-hydroxy group to a greater extent than those without the hydroxy group, and oxidized 20 alpha-hydroxy groups of the steroids in the presence of NADP+. The Km values for 17 alpha-hydroxyprogesterone and 17 alpha-hydroxypregnenolone were 2.9 and 3.4 microM respectively. Although the enzyme was inactive towards androgens and oestrogens with 3- or 17-oxo groups, it reduced several nonsteroidal carbonyl compounds and oxidized trans-benzene dihydrodiol. The enzyme activity was inhibited by synthetic oestrogens, barbiturates, aldose reductase inhibitors and quercitrin. Thus, this enzyme is a novel form of 20 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.149) which structurally and functionally differs from the mammalian and bacterial enzymes.

scholarly journals Stereoselective Reduction of α-Keto Ester and α-Keto Amide with Marine Actinomycetes, Salinispora strains, as Novel Biocatalysts

2011 ◽  
Vol 4 ◽  
pp. BCI.S7877 ◽  
Author(s):  
Kohji Ishihara ◽  
Hirokazu Nagai ◽  
Kazunari Takahashi ◽  
Mariko Nishiyama ◽  
Nobuyoshi Nakajima
Keyword(s):  
Carbonyl Compounds ◽  
Ethyl Pyruvate ◽  
Conversion Ratio ◽  
High Conversion ◽  
Marine Actinomycetes ◽  
Stereoselective Reduction ◽  
Keto Ester ◽  
Keto Esters ◽  
Salinispora Tropica ◽  
High Conversion Ratio

To clarify the potential ability of marine actinomycetes as biocatalysts, the stereoselective reduction of α-keto esters and α-keto amide using Salinispora arenicola and Salinispora tropica was tested. The reduction of ethyl pyruvate and ethyl 2-oxobutanoate by S. tropica gave corresponding alcohol with high conversion ratio and in high e.e. (96% e.e. ( S) and 99% e.e. ( S), respectively). In the presence of l-glutamate as an additive, the reduction of ethyl pyruvate by S. tropica afforded the corresponding ( S)-ethyl lactate with >99% e.e. Furthermore, 2-chlorobenzoylformamide was reduced by S. tropica to the corresponding ( R)-2-chloromandelamide with high conversion ratio and excellent enantioselectivity (>99% e.e.). Thus, it was found that marine actinomycetes, Salinispora strains, had high ability for the stereoselective reduction of carbonyl compounds as useful biocatalysts.

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