Thorneley R N, Willison K R
Biochem J. 1974 Apr;139(1):211-4. doi: 10.1042/bj1390211.
Acetylene-reducing activity of purified nitrogenase from Klebsiella pneumoniae was studied over a range of ATP and Mg(2+) concentrations at 15 degrees C, pH7.8. Inhibition at Mg(2+) concentrations of 2.5-30mm was due to the formation of the inactive complex, Mg(2)ATP. At higher Mg(2+) concentrations an additional inhibitory effect was observed. The results were consistent with a MgATP complex being the active substrate with an apparent K(m)(MgATP)=0.4mm.
在15摄氏度、pH7.8条件下,研究了肺炎克雷伯菌纯化固氮酶在一系列ATP和Mg(2+)浓度范围内的乙炔还原活性。Mg(2+)浓度为2.5 - 30mM时的抑制作用是由于形成了无活性的复合物Mg(2)ATP。在更高的Mg(2+)浓度下,观察到了额外的抑制作用。结果表明,MgATP复合物是活性底物,其表观K(m)(MgATP)=0.4mM。