An Equation for the Nitrogenase Reaction

Abstract

Research in the biochemistry and biophysics of N2 fixation has progressed along two separate but related lines. One deals mainly with the catalytic activity of the enzyme nitrogenase, while the other is concerned chiefly with its physical and chemical characteristics. Productive research in the former was initiated with the preparation of active cell-free extracts in 1960, but characterization work did not get well under way until into the mid-1960’s. By then the over-all reaction characteristics had become reasonably clear, though the detailed reaction mechanism was not established, nor is it yet. Since the mid-1960’s, understanding of the nitrogenase reaction has become increasingly refined, and major advances in defining the physical-chemical nature of the enzyme have been made possible with the availability of pure nitrogenase proteins for analysis. Until now it has been feasible and also fruitful to pursue these two areas rather independently; however, as experimentation becomes more definitive and bears more directly on the mechanism of nitrogenase action, these areas seem destined to overlap increasingly as they blend toward the ultimate goal, the description of nitrogenase catalysis in terms of molecular structure.