Characterization of polyclonal antibodies raised against DNA attachment proteins

Abstract

The eukaryotic nucleus is thought to contain an internal protein scaffolding structure which is present in interphase and metaphase cells. We were interested in identifying some of the protein components of the scaffolding structure by isolating proteins which have DNA attached to them (DNA attachment proteins). DNA attachment proteins have been previously described by our group, and are referred to as proteins 1, 2, 3, and 4, respectively. Their apparent molecular weights (Mr) and isoelectric values (pI) are 70,000, 4.3; 70,000, 5.3; 58,000, 5.3; and 57,000, 4.8, respectively. My project was to produce and characterize polyclonal antibodies made against these four proteins. The DNA attachment proteins were injected into rabbits. The serum was affinity purified using Protein-A sepharose chromatography. Antibody preparations 1, 2, and 4 recognized the specific DNA attachment proteins and did not cross react with the others suggesting that the polyclonal sera recognized distinct and separate epitopes.