Which copper transport protein migrates as an alpha2-globulin?

Which copper transport protein migrates as an alpha2-globulin?

• A. Ceruloplasmin
• B. Haptoglobin
• C. Transferrin
• D. Fibrinogen

Answer: (A)

Copper in the blood is carried mainly by ceruloplasmin, a copper-containing enzyme produced by the liver. Ceruloplasmin binds most of the circulating copper and provides ferroxidase activity. When serum proteins are separated by electrophoresis, ceruloplasmin appears in the alpha-2 globulin region due to its size and charge, so it migrates there. Therefore, the copper transport protein that migrates as an alpha-2 globulin is ceruloplasmin. For context, haptoglobin binds free hemoglobin and is not a copper transporter; transferrin transports iron and is in the beta globulin region; fibrinogen is a clotting factor and is not a copper transporter.

Copper in the blood is carried mainly by ceruloplasmin, a copper-containing enzyme produced by the liver. Ceruloplasmin binds most of the circulating copper and provides ferroxidase activity. When serum proteins are separated by electrophoresis, ceruloplasmin appears in the alpha-2 globulin region due to its size and charge, so it migrates there. Therefore, the copper transport protein that migrates as an alpha-2 globulin is ceruloplasmin.

For context, haptoglobin binds free hemoglobin and is not a copper transporter; transferrin transports iron and is in the beta globulin region; fibrinogen is a clotting factor and is not a copper transporter.