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棕色固氮菌(Azotobacter vinelandii)固氮酶的钼铁蛋白经邻菲啰啉在厌氧或有氧环境中处理后,变为 P-cluster 单一缺失或 P-cluster 和 FeMoco 同时缺失的失活钼铁蛋白。含柠檬酸盐或高柠檬酸盐的重组液都使这两种失活蛋白能恢复固氮酶重组的 H~+和 C_2H_2还原活性,活性恢复程度随反映钼铁蛋白中金属原子簇含量变化的圆二色和磁圆二色谱及金属含量的恢复程度的提高而提高,但它们固 N_2能力的恢复程度则不相同:P-cluster 单一缺失的蛋白用两种重组液重组后均可恢复其固 N_2能力,而 P-cluster 和 FeMoco 同时缺失的蛋白,只有用含高柠檬酸盐的重组液重组才恢复其固 N_2能力,表明含不同有机组分的重组液所组装的 P-cluster 均与天然状态相同,只有含高柠檬酸盐的重组液所组装的 FeMoco 才与天然状态相同,从而证明高柠檬酸盐是 FeMoco 的必需的有机组分。
Molybdenum ferritin of azotobacter vinelandii nitrogenase is treated with phenanthroline in an anaerobic or aerobic environment to become a single deletion of P-cluster or an inactivated molybdenum ferritin with simultaneous deletion of P-cluster and FeMoco . Both recombinant citrate and citrate-containing recombination solutions restored the H ~ + and C_2H_2 reductive activity of recombinant nitrogenase and showed that the degree of activity recovery varied with the number of clusters containing metal clusters in the molybdenum ferritin Dichroism and magnetic circular dichroism and the recovery of metal content increased, but their ability to restore N_2 is not the same: the P-cluster single deletion protein can be restored with two recombinant solutions However, the same missing P-cluster and FeMoco proteins restored their N_2 ability only by recombination with high citrate, indicating that the P-cluster assembled with the reconstituted liquid with different organic components had the same activity as the native state Similarly, only the FeMoco assembled with the high citrate-containing recombination liquid was the same as the natural state, thus confirming that high citrate is an essential organic component of FeMoco.