【摘要】 棕色围氮菌（Azotobacter vinelandii）铜铁蛋白经邻菲啰啉处理后,克分子消光系数δ_100nm和圆二向色性克分子消光系数△δ_450nm以及乙炔还原活性都随着 P-cluster 中 Fe 原子被螯合数目的增加而降低;而与由 Mo、Fe、S 和 DTT 组成的溶液重组后,吸收光谱、圆二色谱和乙炔还原活性又都随着金属组成的恢复而恢复。结果表明,重组溶液使邻菲啰啉处理而缺失 P-cluster 的铝铁蛋白因重新组装 P-cluster 而恢复活性,从而再次证明了 P-cluster 是钼铁蛋白还原底物所不可缺少的重要部分。更多还原

【Abstract】 After the treatment of nitrogenase MoFe protein from Azotobacter vinelandii with O-phen- anthrotine,ε_700nm（molecular extinction coefficient at 700 nm）,Δε_450nm （molecular circular dichroic extinction coefficient at 450 nm） and the acetylene reduction activity of the treated protein were decreased with the increase in iron atoms chelated from P- cluster of the protein. However,they were restored with the restoration of the metal content after reconstitution of the treated protein with reconstituting solution containing Na₂MoO₄,ferric citrate,Na₂S and dithiothreitol.The results showed that the restoration of the reconstituted protein was result- ed from the assembly of new P-cluster in the protein.It seems to be further demonstrated that P-cluster in the MoFe protein is a necessary and important fraction for the protein to reduce substrates.更多还原