PURIFICATION AND PREPARATION OF ANTIBODY TO RNA POLYMERASE-II STIMULATORY FACTORS FROM EHRLICH ASCITES TUMOR-CELLS

An improved method was developed for purification of the protein termed S-II that specifically stimulates RNA polymerase II of Ehrlich ascites tumor cells. The specific activity of the final preparation was 400000 units/mg of protein, which is about 30-fold higher than that of the previous preparation [Sekimizu, K., et al. (1976) Biochemistry 15, 5064], The final preparation gave a single band on both sodium dodecyl sulfate and nondenaturing gel electrophoresis, and the protein extracted from the band on nondenaturing gel had stimulatory activity. S-II is a basic protein with a molecular weight of 40 500. The fundamental characteristics of S-II determined with the previous preparation were confirmed with completely purified S-II. A specific antibody to S-II was prepared. This antibody inhibited only the stimulatory activity of S-II and did not affect the activity of RNA polymerase II itself. Thus, S-II is probably not a component of the mul-timeric proteins of RNA polymerase II. © 1979, American Chemical Society. All rights reserved.