固氮酶铁钼辅基在分离纯化中结构变化的新证据

New Evidence for Structure Change of Iron molybdenum Cofactor from Nitrogenase MoFe Protein in Separation

根据Ｋｉｍ－Ｒｅｅｓ模型［１］，固氮酶铁钼辅基（即ＦｅＭｏｃｏ或Ｍ簇），是由一个ＭｏＦｅ３Ｓ３簇和一个Ｆｅ４Ｓ３簇通过三个Ｓ－桥联接而成．然而，自Ｓｈａｈ等（１９７７）首次从结晶的钼铁蛋白中分离出具有生物重组活性的ＦｅＭｏｃｏ以来，固氮研究者们一直致...

The iron molybdenum cofactor (FeMoco) of nitrogenase MoFe protein from Azotobacter Vinelandii OP was extracted by N methylformamide (NMF).Effects of FeMoco(in NMF) on electronic spectrum and fluorescence intensity (in 1 mol/L NaOH) were investigated by fluorophotometric titrations and compared with results of effects of (NH 4) 2MoS 4 and its complexes with Na 2S,Na 2S 2 and (NH 4) 2S X on relative properties of FDMA.It was found that titration curve for quenching of FDMA with FeMoco was very similar to that for quenching of FDMA with complexes of (NH 4) 2MoS 4 and Na 2S 2(1∶3,mol/mol).The results showed that FeMoco(N) probably contained S S bonds and Its structure was found to be a changing one.