Purification of human ceruloplasmin as a by-product of C1-inhibitor

Human ceruloplasmin (Cp) has been purified from cryoprecipitate-poor plasma as a by-product of the C1-inhibitor production chain. Highly purified Cp was obtained by subsequent ion-exchange chromatography on sulfate-Fractogel EMD and TMAE-Fractogel EMD. Treatments for viral safety included application of the solvent-detergent method and two nanofiltration steps using 35- and 15-nm pore size filters at the end of the process. Overall antigen yield was 95 (±5)%. Purified human ceruloplasmin was studied by electron spin resonance (ESR) to characterize its different types of copper complexes and to check its antioxidant properties. We distinguished three types of complexes: One type-2 Cu(II) with g_//=2.25 and A_//=180 G and two type-1 Cu(II) exhibiting different narrow hyperfine splitting (A_//=72 G and A_//=90 G) with close g_//(2.20 and 2.21). Purified Cp has a specific activity of 24.5±0.2 mU/mg of proteins. This process provides a method for Cp purification that could be easily integrated into modern plasma fractionation.