[Electron factors in peroxidase properties and the mechanism of activation of oxygen with heme-containing proteins].
A quantum-chemical calculation was carried out for the electronic structure of coordination compounds of general formula FeP (L1) (L2) (P-porphine; L1-imidazole or imidazolate; L2-CO, O2 or is absent), modelling the active sites of number of hemoproteins. The elucidation of electronic structures of the complexes under consideration explains the similar shapes and band positions of optical absorption and magnetic circular dichroism spectra of oxy- and carboxycomplexes of myoglobin, hemoglobin, and peroxidase. It is shown that the Coulomb repulsion between electrons of the lone pair of the imidazolate distal nitrogen leads to the transfer of the electronic density from this ligand to the dioxygen. This results in the strong dioxygen activation leading, in particular, to the high catalytical activity of peroxidase.
Stavrov
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Dikusar
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Bersuker
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D001051:Apoenzymes / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D004583:Electrons; D006420:Hemeproteins / Q000378:metabolism*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism*
D001051:Apoenzymes; D006420:Hemeproteins; D009195:Peroxidase; D010100:Oxygen
Elektronnye faktory v svoĭstvakh peroksidazy i mekhanizm aktivatsii kisloroda gemsoderzhashchimi belkami.