中文摘要：

通过 DEAE-52 的列上的缺氧的层析， Q-Sepharose andSeph 压克力 S-200， CrFe 蛋白质准备从 UW3 被获得， Azotobactervinelandii 的异种，它在包含 Cr 媒介上成长了很好。与 MoFe 蛋白质(OP Av1 ) 相比 fromwild 类型紧张 OP，在准备的约 50% 蛋白质有类似的子单元作文并且与 OP Av1 的抗体有有免疫力的反应。准备有 C_2H_2- H~+-andN_2 的 -40 百分比(在 H~+ 减小活动在之间由差别表示了在 Ar 下面并且在 N_2 下面) 到那些的 OP Av1 和 OP Av1 的类似的电子对的减小活动。并且金属分析证明准备包含了 Fe， Cr 和瞬间。，在在约 450 nm 的准备的圆形的二色性(CD ) 光谱类似于 OP Av1 的出现在一样的 g 价值的 threeEPR 信号的相对紧张(g 约 4.3， 3.7 和 2.0 ) 是不同的。EPR-basedcalculated 结果显示出那(1 ) 到 Cr 的瞬间并且 Fe 到的比率(Cr+Mo ) 分别地， CrFe 蛋白质准备， 0.41 和 15 正在显示在准备，到 MoFe 蛋白质的比率包含 ofCr 蛋白质是大约 2.5；(2 ) 到 Fe 并且到准备的 Cr 的活动的比率分别地接近了活动的比率到 Fe 并且到 OP Av1 的瞬间；(3 ) EPR 的比率在到 CrFe 蛋白质的 Cr 的值大约到瞬间的约 83% 那些， 0% 和约 40% 的上述三 g 表明紧张。OP Av1，分别地。结果进一步显示 CrFe 蛋白质力量是一个新 ni-trogenase 部件我有在余因子由 Mn MoFe 蛋白质包括 metallocluster 到那些而不是瞬间的简单代替的类似的功能和结构的蛋白质。

英文摘要：

Through the anoxic chromatography on the columns of DEAE-52, Q-Sepharose and Sephacryl S-200, a CrFe protein preparation was obtained from UW3, a mutant of Azotobacter vinelandii, which grew well on the Cr-containing medium. Compared with MoFe protein （OP Avl） from wild-type strain OP, -50% protein in the preparation had similar subunits composition and had immune reaction with antibody of OP Avl. The preparation had -40% of C2H2-, H^＋- and N2 （expressed by the difference in H^＋-reduction activity between under Ar and under N2） -reduction activity of OP Avl and similar electron pairs to those of OP Avl. And metal analysis showed that the preparation contained Fe, Cr and Mo. The circular dichroism （CD） spectrum in the preparation at -450 nm was similar to that of OP Avl, while the relative intensities of three EPR signals appearing at the same g values （g≈4.3, 3.7 and 2.0） were different. The EPR-based calculated results showed that （1） the ratios of Mo to Cr and of Fe to （Cr＋Mo） of the CrFe protein preparation were 0.41 and 15, respectively, indicating that in the preparation, a ratio of Cr-containing protein to MoFe protein was about 2.5; （2） the ratios of activity to Fe and to Cr of the preparation were close to the ratios of activity to Fe and to Mo of OP Av1, respectively; （3） the ratios of the EPR signal intensities at the above three g values to Cr of CrFe protein were about -83%, 0% and -40% of those to Mo of OP Avl, respectively. The results indicate further that CrFe protein might be a new nitrogenase component I protein with a similar function and structure including metallocluster to those of MoFe protein instead of simple replacement of Mo by Mn in the cofactor.