Studies of the interaction between aminoacyl-tRNA synthetase and transfer ribonucleic acid by equilibrium partition

The partition behavior of isoleucyl-tRNA synthetase, leucyl-tRNA synthetase and tRNA in aqueous two-phase systems composed of the polymers poly(ethyleneglycol) and dextran was investigated. From the results of this investigation a two-phase system could be derived which can be employed for the study of the interactions between synthetases and their cognate tRNAs by equilibrium partition. These measurements show that in each case one molecule of cognate tRNA is bound per molecule of enzyme. The binding constants were in the range 1-5micronM-1. It could be demonstrated that equilibrium partition is a useful method for the study of interactions between macromolecules.