Occurrence of aminoacyl-tRNA synthetase complexes in quiescent wheat germ

The cellular distribution of arginyl-tRNA, leucyl-tRNA, methionyl-tRNA and phenylalanyl-tRNA synthetases from quiescent wheat germ shows that these enzymes participate to various high molecular weight complexes from 3.10⁶ to 3.10⁵. Two types of interactions were discriminated by salt washing. The greater part of these complexes are weakly bound and destroyed by conventional enzymatic extraction procedures which release the free enzymes. Sedimentation constants of complexes show that they have a common size at 18–20S, but higher sedimentation constants were also observed (? 40–60 S). Investigations by gel filtration lead to evidence that the complexes contain a little amount of conjugates.