Ferredoxin-dependent Nitrite Reductase from Spinach Leaves |
| |
Authors: | Masakazu Hirasawa Goro Tamura |
| |
Institution: | Department of Agricultural Chemistry, Faculty of Horticulture, Chiba University, Matsudo, Chiba-ken 271, Japan |
| |
Abstract: | A ferredoxin-dependent nitrite reductase from Spinacea oleracea was purified approximately 180-fold, with a specific activity of 285 units/mg protein. This purified enzyme also had methyl viologen-dependent nitrite reductase activity, with a specific activity of 164 units/mg protein. After disc electrophoresis with polyacrylamide gel, the purified enzyme showed one major and one minor protein band.The molecular weight of the enzyme was estimated to be 86,000 from Ultrogel filtration. This purified enzyme in oxidized form had absorption peaks at 278, 390, 573 and 690 nm. The absorbance ratios, A390: A278 and A673: A390 were 0.61 and 0.37, respectively.By applying the purified enzyme to DEAE-Sephadex A–50 column chromatography, the ferredoxin-dependent nitrite reductase activity was selectively decreased. However, the methyl viologen-dependent nitrite reductase activity was increased, with a specific activity of 391 units/mg protein. This modified enzyme was homogeneous by disc electrophoresis with polyacrylamide gel. |
| |
Keywords: | Shiga toxin GMCSF baculovirus immunotoxin pUltraBac1 |
|
|