Demonstration and characterization of polyoma-tumor-associated antigenic components using preparative and analytical polyacrylamide gel electrophoresis.

Glycoproteins from surface of polyoma tumor cells extracted with 3M KCl were separated in preparative electrophoresis and elution profile showed eight fractions, which were further separated by polyacrylamide gel electrophoresis and SDS-PAGE. Twenty polypeptides were detected, their molecular weights were in range 10000-155000 but most of them had Mr 17000-68000 and isoelectric points ranged between 3.9 and 5.5. Results of immunodiffusion after absorption of immune sera suggested that tumor associated antigens were present in fraction II in which four glycopeptides of molecular weights 14,000, 67,000, 36,000, 18,000 were found. These polypeptides had isoelectric points 5.3, 5.9, 6.4 and 6.6 respectively. Antigens of H-2 system were detected in fraction IV, which contained three glycopeptides of molecular weights 18000, 37000 and 48000 and isoelectric points 6.0, 5.8, and 6.7 respectively.