Hageman R V, Burris R H
Proc Natl Acad Sci U S A. 1978 Jun;75(6):2699-702. doi: 10.1073/pnas.75.6.2699.
Nitrogenase and nitrogenase reductase dissociate after each electron is transferred between them, as shown by the occurrence of a lag phase approximately as long as the average turnover time of nitrogenase before hydrogen evolution occurs. Because nitrogenase was present in the reaction mixture in large excess over nitrogenase reductase, the electrons donated by nitrogenase reductase must have been distributed randomly over all of the nitrogenase present. This is accomplished by nitrogenase reductase molecules associating randomly with nitrogenase molecules for each cycle of electrons transferred. The fact that ATP is hydrolyzed without a lag indicates both that electron transfer occurs during the lag and the ATP hydrolysis is coupled to electron transfer from nitrogenase reductase to nitrogenase and not to substrate reduction. The observations support the suggestion that it now is desirable to alter nomenclature to designate the MoFe protein as nitrogenase and the Fe protein as nitrogenase reductase.
固氮酶和固氮酶还原酶在每次电子传递后会解离，这可由一个延迟期的出现得到证明，该延迟期的时长大约与固氮酶在氢气释放发生前的平均周转时间相同。由于反应混合物中固氮酶的含量大大超过固氮酶还原酶，固氮酶还原酶提供的电子必定随机分布于所有存在的固氮酶分子上。这是通过固氮酶还原酶分子在每次电子传递循环中与固氮酶分子随机结合来实现的。ATP水解没有延迟这一事实表明，电子传递在延迟期内发生，且ATP水解与从固氮酶还原酶到固氮酶的电子传递相偶联，而不是与底物还原相偶联。这些观察结果支持了这样的建议，即现在需要改变命名法，将钼铁蛋白指定为固氮酶，将铁蛋白指定为固氮酶还原酶。
