The application of DNA-cellulose chromatography in the isolation of immunoglobulin M and complement component C4b-binding protein from human serum.
By utilising the ability of some anionic serum proteins to bind to DNA-cellulose, at physiological pH and ionic strength, two such proteins have been purified and identified as immunoglobulin M (IgM) and complement component C4b-binding protein (C4BP). The method entails ammonium sulphate precipitation followed by QAE-Sephadex, DNA-cellulose and Sephacryl S-300 chromatographic steps. Fractionation of the anionic proteins eluting from QAE-Sephadex over a selected range of ionic strength has afforded IgM which was characterised electrophoretically and immunochemically. A mixture containing IgM complexed with C4BP has also been obtained by utilizing fractions eluted from QAE-Sephadex at higher ionic strength. C4BP can be isolated from this mixture by using immunoaffinity chromatography to remove IgM.
D002352:Carrier Proteins / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003169:Complement Inactivator Proteins; D004247:DNA / Q000032:analysis*; D006023:Glycoproteins; D006801:Humans; D007122:Immunoelectrophoresis; D007075:Immunoglobulin M / Q000302:isolation & purification*
D002352:Carrier Proteins; D003169:Complement Inactivator Proteins; D006023:Glycoproteins; D007075:Immunoglobulin M; D004247:DNA