Purification and functional characterization of C4b-binding protein (C4BP).
C4b-binding protein (C4BP) is a soluble, 570 kDa large glycoprotein, present in plasma at a concentration of approximately 200 mg/L. C4BP is the main inhibitor of the classical and lectin pathways of complement, where it controls C4b-mediated reactions. Here, we describe a method for purification of C4BP from human plasma, which is based on barium chloride precipitation, anion exchange chromatography, and gel filtration. We also describe a functional assay, in which C4BP's cofactor activity to factor I, in the degradation of C4b, can be assessed.
Department of Laboratory Medicine, Section of Medical Protein Chemistry, The Wallenberg Laboratory, Lund University, Skåne University Hospital, Malmö, Sweden.
Frida C
FC
Mohlin
Anna M
AM
Blom
D002852:Chromatography, Ion Exchange; D003167:Complement Activation; D050716:Complement C4b-Binding Protein / Q000302:isolation & purification* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans
D050716:Complement C4b-Binding Protein