Proliferation-associated nuclear antigen Ki-S1 is identical with topoisomerase II alpha. Delineation of a carboxy-terminal epitope with peptide antibodies.

摘要: Proliferation-linked expression of the nuclear Ki-S1 antigen is a significant prognostic indicator in mammary carcinomas. Here, we show staining protein 170 kd by antibody immunoblots Saccharomyces cerevisiae expressing human topoisomerase II alpha but not parental strain. In HL-60 cells containing both isoforms II, binds selectively to 170-kd isoenzyme similar fashion as peptide-antibodies directed against amino acid residues 1 15 or 1512 1530 alpha. Conversely, antibodies carboxyl-terminal sequences beta stain 180-kd protein. The immunoreactive pattern V8 endoproteinase restriction digests was identical for Ki-S1-antibody and different 15. Rf values smallest fragment commonly recognized carboxy terminus-specific peptide-antibody place epitope within last 495