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

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

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。

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.