Purification and preparation of antibody to RNA polymerase II stimulatory factors from Ehrlich ascites tumor cells

Abstract

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 400,000 units/mg of protein, which is .apprx. 30-fold higher than that of the previous preparation. 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 MW 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. S-II is probably not a component of the multimeric proteins of RNA polymerase II.