钼,铁,硫化合物激活曝氧的棕色固氮菌固氮酶钼铁蛋白的研究

曝氧后,棕色固氮菌(Azotobacter vinelandii)固氮酶钼铁蛋白的催化活性和圆二色信号都显著降低,而吸收光谱则显著增加。与钼、铁、硫化合物和二硫苏糖醇组成的重组溶液保温后,曝氢蛋白的圆二色信号和吸收光谱几乎完全恢复至天然状态的同时,乙炔还原活性也得到了显著的恢复,表明重组溶液可使曝氧蛋白中的 P-cluster和其它活性部位都得到了不同程度的修复。

STUDIES ON THE REACTIVATION OF AERATED NITROGENASE MoFe PROTEIN FROM AZOTOBACTER VINELANDII BY THE COMPOUNDS OF IRON MOLYBDENUM AND SULFUR

After the exposure to air,the crystalline nitrogenase MoFe protein from Azotobacter vine- dii was resulted in the remarkable increase in its absorption (ABS) and the significant decrease in its activity and circular dichroism(CD) However,when the aerated MoFe pro- ein was incubated with the reconstituting solution which consisted of Na_2MoO_4,ferric citra- te,Na_2S aud dithiothreitol,the ABS and CD of the aerated MoFe protein both were comple- tely restored,simultaneously with the significant restoration of acetylene reduction.It is shown that the P-cluster and other parts related to the protein activity which was damaged by O_2 are able to be repaired to a certain extent by the reconstituting solution.