[Electron transport in hemoproteins. IX. The effect of zinc ions on the rate of oxymyoglobin oxidation by ferricytochrome c].
The effect of zink ions, which according to the X-ray data are bound to the His GH1 residue of myoglobin, has been investigated. It is shown that the electron transfer in the system is almost completely inhibited at the equimolar Zn2+ concentration in the pH range 5 to 8. Unlike the reaction between the intact MbO2 and Cyt c, the electron transfer rate in this case does not depend on pH and ionic strength of the solution. Further increase of Zn2+ concentration up to the 20-fold molar excess has no significant effect on the rate of the process. Since the thermodynamic characteristics of the redox reaction between MbO2 and Cyt c are not altered in the presence of Zn2+, the findings obtained can be interpreted as indicating the important role of His GH1 in the formation of productive electron transfer complex.
Postnikova
G B
GB
Tselikova
S V
SV
D000818:Animals; D002942:Circular Dichroism; D003574:Cytochrome c Group / Q000378:metabolism*; D004579:Electron Transport / Q000187:drug effects; D066298:In Vitro Techniques; D009211:Myoglobin / Q000378:metabolism*; D010084:Oxidation-Reduction; D011487:Protein Conformation; D013552:Swine; D014907:Whales; D015032:Zinc / Q000378:metabolism / Q000494:pharmacology*
D003574:Cytochrome c Group; D009211:Myoglobin; C017595:oxymyoglobin; D015032:Zinc
Izuchenie perenosa élektrona v gemoproteinakh. IX. Vliianie ionov tsinka na skorost' okisleniia oksimioglobina ferritsitokhromom c.