| Title |
Nitroreductase II Involved in 2,4,6-Trinitrotoluene Degradation: Purification and Characterization from Klebsiella sp. C1 |
| Author |
Jung-Hye Shin and Hong-Gyu Song* |
| Address |
Division of Life Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea |
| Bibliography |
Journal of Microbiology, 47(5),536-541, 2009,
|
| DOI |
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| Key Words |
nitroreductase, Klebsiella sp., enzyme purification, trinitrotoluene |
| Abstract |
Three 2,4,6-trinitrotoluene (TNT) nitroreductases from Klebsiella sp. C1 have different reduction capabilities that can degrade TNT by simultaneous utilization of two initial reduction pathways. Of these, nitroreductase II was purified to homogeneity by sequential chromatographies. Nitroreductase II is an oxygen- insensitive enzyme and reduces both TNT and nitroblue tetrazolium. The N-terminal amino acid sequence of the enzyme did not show any sequence similarity with those of other nitroreductases reported. However, it transformed TNT by the reduction of nitro groups like nitroreductase I. It had a higher substrate affinity and specific activity for TNT reduction than other nitroreductases, and it showed a higher oxidation rate of NADPH with the ortho-substituted isomers of TNT metabolites (2-hydroxylaminodinitrotoluene and 2-aminodinitrotoluene) than with para-substituted compounds (4-hydroxylaminodinitrotoluene and 4-aminodinitrotoluene). |
