The 400-MHz 1H-NMR spectra of L-isoleucine were measured in the presence of Escherichia coli isoleucyl-tRNA synthetase (IleRS). Because of chemical exchange of L-isoleucine between the free state and the IleRS-bound state, transferred nuclear Overhauser effect (TRNOE) was observed among proton resonances of L-isoleucine. The IleRS-bound L-isoleucine was found to take the gauche+ form about the Cα-Cβ bond and the trans form about the Cβ-Cγ1 bond. The TRNOE analysis is useful for studying the amino acid discrimination mechanism of ammoacyl-tRNA synthetases.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)