Ceruloplasmin Detection by SDS-PAGE, Immunoblotting, and In Situ Oxidase Activity

Ceruloplasmin is an acute-phase reactant that functions as a ferroxidase, oxidizing Fe⁺⁺ to Fe⁺⁺⁺ , the latter being able to combine with apotransferrin to form transferrin, the primary iron transport protein in the plasma. Ferroxidases indirectly reduce formation of hydroxyl radical by preventing the participation of Fe⁺⁺ in the Fenton reaction (1 ). Ceruloplasmin is primarily produced in the liver and transported in the plasma, but has also been shown to be produced in other tissues (2-5 ). We describe here methods for detecting ceruloplasmin using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by either immunoblotting or assay of in situ oxidase activity.