On the mechanism of citrate inhibition of ceruloplasmin ferroxidase activity.
Ceruloplasmin is a plasma protein, which oxidizes ferrous ions in a catalytic manner. It is considered to function as a ferroxidase in vivo. Citrate was found to inhibit the reaction. The ceruloplasmin catalyzed oxidation of p-phenylenediamines, however, was not affected by citrate. The inhibitory effect is proposed to be due to formation of Fe(2+)-citrate, which does not react with ceruloplasmin. The stability constant for the Fe(2+)-citrate complex estimated from the present inhibition study is in good agreement with previously published data.
Løvstad
R A
RA
Department of Medical Biochemistry, Institute of Basic Medical Sciences, University of Oslo, Norway.
D002384:Catalysis; D002570:Ceruloplasmin / Q000037:antagonists & inhibitors*; D002951:Citrates / Q000494:pharmacology*; D019343:Citric Acid; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005296:Ferrous Compounds / Q000378:metabolism*; D006801:Humans; D010084:Oxidation-Reduction
D002951:Citrates; D004791:Enzyme Inhibitors; D005296:Ferrous Compounds; D019343:Citric Acid; D002570:Ceruloplasmin