Malignancy-Associated DNA-Binding Protein C3DP from Human Serum. Further Characterization and Purification of C3DP Retaining its DNA-Binding Affinity

Abstract

C3DP, a malignancy-associated DNA-binding protein from human serum[1], was purified to homogeneity without loss of its DNA-binding affinity. For this purpose normal human serum was submitted to affinity chromatography on Con A-Sepharose and DNA-cellulose and to preparative polyacrylamide gel electrophoresis. The purified C3DP was identified by immunodiffusion and sodium dodecylsulfate polyacrylamide gel electrophoresis and it bound to DNA by DNA-cellulose chromatography. The isoelectric point of C3DP was determined to 4.9 by isoelectric focusing.