Nitrogenase physical properties

Unlike the nitrogenases, which do not vary much in composition and physical properties with the source, nitrate reductases vary considerably from one organism to the next. The only feature which they all seem to have in common is an absolute requirement for the presence of molybdenum. 

More detailed information about structure and spectral properties of the nitrogenase Fe-clusters were obtained by a combination of physical methods. The structure suggested at that time and variation of spectra parameters is presented in Fig. 3.1, which was plotted on the basis of the data obtained in the works of Ohrme-Johnson s and Miinck s groups cited above. Subsequent investigations have confirmed the main parameters and added some important details. 

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