STUDIES ON COPPER METABOLISM. XXXI. ERYTHROCYTE COPPER*

Abstract

A chromatographic method for the preparation of immunologically homogeneous erythrocuprein has been described. The physical and chemical properties of the erythrocuprein isolated were similar to those of the erythrocuprein isolated previously. The erythrocuprein concentration was determined by the precipitin technique in erythrocytes from 20 normal subjects. The mean value [plus or minus] 1 SD was 16 [plus or minus] 2.9 mg per 100 ml of packed cells. Since erythrocuprein contains 3.4 [mu]g of copper per mg of protein, the copper in erythrocuprein accounts for about 60% of the total erythrocyte copper. Quantitative and qualitative study of erythrocuprein in erythrocytes from patients with a variety of disorders failed to disclose alterations from the normal. The concentration of erythrocuprein was independent of alterations in the concentration of serum copper. Erythrocuprein was detected in human brain, liver and kidney. Hemolysates of pig, rabbit, chicken and bovine erythrocytes failed to react with antihuman erythrocuprein rabbit serum in the agar diffusion system. A reaction of partial identity was obtained with a hemolysate of squirrel monkey (Saimiri sciureus) erythrocytes. A second erythrocyte copper fraction has been separated from erythrocuprein by chromatography on diethylaminoethyl-cellulose and from hemoglobin by chromatography on carboxymethyl-cellulose. The nature of the copper compound(s) in this fraction is unknown. When radio-copper was incubated with whole blood, radioactivity was detected both in the 3rythrocuprein and in the second copper-containing fraction.