Application of capillary zone electrophoresis to the study of interactions between Bacillus subtilis tryptophanyl-tRNA synthetase and tRNA(TrP)

The application of capillary zone electrophoresis to the study of interactions between Bacillus subtilis tryptophanyl-tRNA synthetase (TrpRS) and tRNA(Trp) is described. Significant changes in peak shape of tRNA(Trp) incubated with TrpRS indicated the occurrence of interactions between TrpRS and tRNA(Trp) in pH 8.0 Tris-HCl buffer containing 0.1 mmol L-1 EDTA and 1 mmol L-1 - 5 mmol L-1 MgCl2. Addition of Mg2+ decreased the electrophoretic mobility of tRNA(Trp), which illustrated that conformation of tRNA(Trp) depended on Mg2+. The dissociation constant of the TrpRS-tRNA(Trp) complex was estimated to be 0.63 mu mol L-l at 25 degrees C in buffer solution.