Cooperativity nitrogenase

As the preceding discussion of nitrogenase metal-sulfur clusters indicate, analysis of complex bioinorganic systems requires the use of multiple analytical techniques and the cooperative exchange of data and ideas of many researchers. The descriptions in this chapter have attempted to give students some idea of the scope and complexity of instrumental techniques available to the bioinorganic chemist. It has not been intended to be either comprehensive or theoretical in presentation. Students are encouraged to acquaint themselves further with the theory and practice of instrumental techniques, especially those that are important to their particular research interests. 

In summary, reduction of dinitrogen by nitrogenase requires cooperativity among nitrogenase s subunits and involves three basic types of electron transfer steps ... 

Frank, P., Angove, H. C., Burgess, B. K., and Hodgson, K. O. (2001) Determination of ligand binding constants for the iron-molybdenum cofactor of nitrogenase monomers, multimers, and cooperative behavior, J. Biol. Inorg. Chem. 6, 683-697. 

A significant breakthrough has occurred in the crystallographic analysis of the iron-molybdenum protein of nitrogenase. The overall distribution of the metal clusters in the protein is shown in Eigure 7.40. The distance between the two FeMoco units is fully consistent with each cofactor acting as an independent active site. On the other hand, the closeness of the P cluster and FeMoco centers in each unit is indicative of their likely cooperation in the N2 fixation reaction. 

The enzymology and biochemistry of nitrogenases started only a few years before the first dinitrogen metal complex was discovered by Allen and Senoff in 1965. Cooperation and mutual encouragement increased when more and more results were found on both sides. Two iron-sulfur proteins are involved in the nitrogenase complex. The larger protein, the nitrogenase itself, consists of four subunits and has an... 

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