氧对固氮螺菌(Azospirillum brasilense)Yu62固氮酶活性的调节作用  

THE REGULATION OF NITROGENASE ACTIVITY BY OXYGEN IN AZOSPIRILLUM BRASILENSE Yu 62

作　　者：王继文[1] 李永兴[1] 胡长征[1] 李久蒂[1] 

机构地区：[1]中国科学院植物研究所

出　　处：《微生物学报》1991年第5期351-356,共6页Acta Microbiologica Sinica

基　　金：863经费资助项目

摘　　要：本文研究了在好气条件下,在以谷氨酸为氮源的液体培养基中,固氮螺菌(Azospirillumbrasilense)Yu62固氮酶形成的条件及溶氧压对固氮酶活性的影响。厌氧使整体细胞固氮酶迅速失活;而见氧后固氮酶又重新恢复活性。Western blotting 实验证实,这种可逆失活的分子基础,是由于固氮酶铁蛋白-亚基被修饰和去修饰。呼吸抑制剂 KCN 对固氮酶活性的抑制,亦是由于固氮酶铁蛋白被修饰。因此推论细胞内的能量状态可能是启动固氮酶活化酶系统的重要信号。谷氨酰胺合成酶的抑制剂 MSX 不能去除厌氧和 KCN 引起的抑制作用。结果表明:固氮酶活性的 NH^+_-和厌氧关闭可能通过不同的机制起作用。The condition of nitrogenase expressionand the regulation of N_2ase activity in liquidglutamate medium in air was described.TheDOT effected on N_2ase activity.An anaerobiccondition in the incubator caused an inhi-bition of N_2ase activity immediately and com-pletely.By Western blotting experiment,theresults demonstrated that the molecular basisof reversible inhibition of N_2ase activity wascovalent modification and demodification ofthe Fe protein of N_2ase.The respiratory inhi-bitor KCN inhibited N_2ase activity rapidlyand caused the covalent modification of the Feprotein of N_2ase.GS inhibitor MSX couldabolished the inhibition caused by an anaerobiccondition and KCN.The energy state in cellmay be a important signal for tragging thecovalent modification system of the Fe protein.

关 键 词：固氮螺菌 固氮酶 活性 调节 

分 类 号：Q939.113[生物学—微生物学]