PURIFICATION OF ARGINYL-RNA SYNTHETASE FROM RAT LIVER

1. 1. The arginyl-RNA synthetase (l-arginine:tRNA ligase (AMP)) of rat liver has been purified 100-fold. The purified enzyme was stable for several months at -20° in 20% glycerol. 2. 2. The kinetic properties of this enzyme were similar to those of other aminoacyl-RNA synthetases. The Km values for arginine, ATP and rat liver tRNA were 1.25, 1.9 and 0.37 μM, respectively. The Km values for tRNA of rat liver, yeast and Escherichia coli were 0.37, 0.66 and 0.17 μM, respectively. 3. 3. The 100-fold purified enzyme is heat labile, but is stabilized considerably by the addition of glycerol. © 1969.