The activities of aminoacyl-tRNA synthetase phosphatase and aminoacyl-tRNA synthetases in MPC-11 and Krebs II ascites cells.

The activity of aminoacyl-tRNA synthetase phosphatase as well as the activities of aminoacyl-tRNA synthetases in Krebs II ascites cells and MPC-11 cells have been investigated. The activity of the phosphatase was greater in the tumor cells than in normal tissues. The aminoacyl-tRNA synthetase activities were 100-300 times higher than the activities found in the uterus of ovariectomized mice, but not very different from the activities found in the liver. The influence of cyclic AMP. 2-deoxyadenosine 3-phosphate and 2-deoxyguanosine 3-phosphate on the growth of MPC-11 cells, grown in suspension culture, was also investigated.