Studies on microbial protein synthesis with Azotobacter vinelandii as the test organism II. Incorporation of radioactive amino acids into protein of cell-free particulate preparations

Abstract

It has been found that a cell-free particulate preparation from A. vinelandii sedimentable at low gravitational field (2,000-30,000 × g) actively incorporates the amino acids, glycine, glutamate and leucine, into protein. The requirements of the incorporating system have been studied in detail. Treatment of the particles with NaCl reduces their incorporating activity to a considerable extent. Rat-liver pH 5 fraction or pH 5 fraction prepared from A. vinelandii extracts reactivates the particles. The bacterial pH 5 fraction can also substitute for the rat-liver pH 5 fraction in its capacity of incorporating amino acids into microsomes of rat liver.