| Title | Purification and Characterization of NADPH-Dependent Cr(VI) Reductase from Escherichia coli ATCC 33456 |
|---|---|
| Author | Woo-Chul Bae1, Han-Ki Lee1, Young-Chool Choe1, Deok-Jin Jahng2, Sang-Hee Lee1, Sang-Jin Kim3, Jung-Hyun Lee3, and Byeong-Chul Jeong1,* |
| Address | 1Division of Bioscience and Bioinformatics, Myongji University, Yongin, 449-728, Republic of Korea, 2Department of Environmental Engineering and Biotechnology, Myongji University, Yongin, 449-728, Republic of Korea, 3Microbiology Laboratory, Korea Ocean Research and Development Institute, Ansan, 425-600, Republic of Korea |
| Bibliography | Journal of Microbiology, 43(1),21-27, 2005, |
| DOI | |
| Key Words | Cr(VI) reductase, Escherichia coli ATCC 33456, purification |
| Abstract | A soluble Cr(VI) reductase was purified from the cytoplasm of Escherichia coli ATCC 33456. The molecular mass was estimated to be 84 and 42 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis, respectively, indicating a dimeric structure. The pI was 4.66, and optimal enzyme activity was obtained at pH 6.5 and 37^oC. The most stable condition existed at pH 7.0. The purified enzyme used both NADPH and NADH as electron donors for Cr(VI) reduction, while NADPH was the better, conferring 61% higher activity than NADH. The K_m values for NADPH and NADH were determined to be 47.5 and 17.2 umol, and the V_max values 322.2 and 130.7 umol Cr(VI) min^-1mg^-1 protein, respectively. The activity was strongly inhibited by N-ethylmalemide, Ag^2+, Cd^2+, Hg^2+, and Zn^2+. The antibody against the enzyme showed no immunological cross reaction with those of other Cr(VI) reducing strains. |
| Download PDF | p[1].21-27.pdf |