含铬重组液激活部分缺失金属原子簇的钼铁蛋白的研究

棕色固氮菌（Ａｚｏｔｏｂａｃｔｅｒ ｖｉｎｅｌａｎｄｉｉ）固氮酶钼铁蛋白经邻菲口罗啉和Ｏ２ 处理后，变为部分缺失ＦｅＭｏｃｏ 和Ｐ－ｃｌｕｓｔｅｒ的失活蛋白。与由Ｋ２ＣｒＯ４、高柠檬酸铁、Ｎａ２Ｓ和二硫苏糖醇组成的重组液保温后，处理蛋白对乙炔和质子还原的活性都得以显著恢复；然而，它的吸收光谱和圆二色谱虽有明显恢复，但仍与还原钼铁蛋白有所不同。这表明，激活蛋白中也许存在功能与钼铁蛋白相似，而结构则有所差异的含铬（ＣｒＦｅ）蛋白

REACTIVATION OF PARTIALLY METALLOCLUSTER DEFICIENT MoFe PROTEIN BY CHROMIUM CONTAINING RECONSTITUENT SOLUTION

By treating the reduced MoFe protein from Azotobacter vinelandii with o phenanthroline and O 2, partially deficient in both FeMoco and P cluster and inactive protein could be obtained. After incubating the treated protein with a reconstituent solution containing K 2CrO 4, ferric homocitrate, Na 2S and dithiothreitol, a reactivated protein could be obtained. The absorption spectrum, circular dichroism spectrum, and the C 2H 2 and proton reduction activities of the reactivated protein were remarkably recovered. However, the spectra were somewhat different from those of the reduced MoFe protein. The results showed that some of the reactivated protein might be Cr containing protein (CrFe protein) which were similar in function, but somewhat different in structure from MoFe protein.