Ceruloplasmin

ceruloplasmin [sə¦rül·ō¦plaz·mən]

(biochemistry)

The copper-binding serum protein in human blood.

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Ceruloplasmin 

a copper-containing protein of the α₂-globulin fraction of blood plasma. It was first discovered and isolated by the Swedish scientists C. Holmberg and C. Laurell in 1948. Its content in human plasma is 0.2–0.3 mg/ml. Ceruloplas-min, which has a molecular weight of 130,000, is bound to 60–99 percent of all the plasma copper ions. Its two molecular forms differ in the number of carbohydrate chains, which consist of galactose, mannose, fucose, N-acetylglucosamine, and sialic-acid residues. Ceruloplasmin has some catalytic activity, oxidizing polyamines, polyphenols, and ascorbic acid (vitamin C). It also takes part in hematopoiesis and the transport of copper to sites where other copper-containing proteins, such as cytochromoe oxidases, are synthesized. In addition, it apparently participates in the regulation of the level of biogenic amines.

There exist genetically determined variants of ceruloplasmin caused by the presence of mutant alleles. The level of ceruloplas-min in blood serum increases nonspecifically during pregnancy, infections, anemias, and malignancies but decreases during the Wilson-Konovalov disease and some other diseases.

N. N. CHERNOV