[Dismutation of superoxide radicals by ceruloplasmin--details of the mechanism].
Like superoxide dismutase (SOD), human ceruloplasmin (Cp) scavenges superoxide anion radicals injected into the solution with the aid a high-voltage generator, hydrogen peroxide being the product of reaction. The O2-/H2O2 ratio is close to 2:1. The dismutase activity of Cp is about 1500 times lower than that of Cu, Zn-SOD isolated from human erythrocytes. The dismutation of O2- accomplished by SOD, "free" copper ions, native Cp or partly copper-depleted Cp, is inhibited with equal efficiency by cyanide. All the copper ions of the multicopper catalytic center of Cp are not essentially required for the dismutation of O2-, since the enzyme depleted of all type 2 Cu2+ and partly of type 1 Cu2+ lost none of its dismutase activity. Type 1 copper ions of Cp seem to play the leading role in the one-electron transfer occurring upon dismutation of O2-.
Vasil'ev
V B
VB
Kachurin
A M
AM
Soroka
N V
NV
D002570:Ceruloplasmin / Q000494:pharmacology*; D005609:Free Radicals; D013482:Superoxide Dismutase / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism*
D005609:Free Radicals; D013481:Superoxides; D013482:Superoxide Dismutase; D002570:Ceruloplasmin
Dismutirovanie superoksidnykh radikalov tseruloplazminom--detali mekhanizma.