含铼重组液对部分缺失金属原子簇的钼铁蛋白的激活作用

Reactivation of Partially Metallocluster-deficient MoFe Protein by Rhenium-containing Reconstituent Solution 

棕色固氮菌(AzotobactervinelandiiLipmann)固氮酶MoFe蛋白经邻菲啉和空气处理后,成为部分缺失P_cluster和FeMoco的失活蛋白。与由Re2O7、高柠檬酸铁、Na2S和二硫苏糖醇(DTT)组成的无圆二色(CD)谱信号的重组液保温后,保温蛋白对乙炔和质子还原的活性都得以显著恢复;紫外和可见光CD谱虽有明显恢复,但仍与还原MoFe蛋白有所差异。这表明:1)保温的蛋白液中除含有未被邻菲啉等处理而破坏的完整MoFe蛋白外,还可能存在新组装的含Re的固氮酶;2)新组装的ReFe蛋白和MoFe蛋白可能在固氮能力上相似。

When the reduced MoFe protein from Azotobacter vinelandii Lipmann was treated with o _phenanthroline and air, an inactive protein partially deficient in both FeMoco and P_cluster could be obtained. After incubating the treated protein with a reconstituent solution containing Re 2O 7, ferric homocitrate, Na 2S and dithiothreitol, which had no circular dichroism (CD) signal, the ultraviolet and visible CD spectra, the C 2H 2 and H +_reduction activity of the incubated protein were significantly recovered. However, the spectra were somewhat different from those of the reduced MoFe protein. The results showed that: 1) in the incubated protein solution there was possibly a new recombined ReFe protein besides the intact MoFe protein which was not destroyed by the treatment with o _phenanthroline and air; 2) it might be possible that both ReFe protein and MoFe protein exhibited similar ability of nitrogen fixation, although they were somewhat different in structure.