Molybdenum complexes histidine

However, when the X-ray crystal structure of the MoFe protein was examined, it was clear that homocitrate could not directly hydrogen bond to the histidine, since the carboxylate group and imidazole are stacked parallel to each other in the crystal. Nevertheless, as noted in the previous section, studies on model complexes have suggested that homocitrate can become monodentate during nitrogenase turnover, with the molybdenum carboxylate bond breaking to open up a vacant site at molybdenum suitable for binding N2. 

Molybdenum(II) complexes mandelic acid, 474 Molybdenum(IV) complexes cyanides synthesis, 9 histidine, 747... 

MoFe-Protein contains a second cluster, the M-cluster. [33] This is covalently bonded to cysteine and histidine of the a-suhunit. A homocitrate anion R)-2-Hydroxyhutane-l,2,4-tricarhoxylic acid) is complexed as a bidentate ligand with molybdenum (Fig. 4.5). On the basis of better resolved X-ray structural analysis and quantum mechanical calculations, initially it was thought, a nitrogen atom is located in the centre of the Fe/Mo complex, [34] but more recent results gave evidence for an interstitial carbido ligand [35,36], which is unprecedent in bioinorganic chemistry. 

The iron-molybdenum cofactor of nitrogenase is one of the more complex inorganic cofactors. It consists of seven iron, one molybdenum, and nine sulfur atoms. The cofactor is held in place through an iron-cysteine interaction on one end and a molybdenum-histidine interaetion... 

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