Improved 1HN-detected triple resonance TROSY-based experiments.

A pulse scheme resulting in improved sensitivity in TROSY-based 1HN-detected triple resonance experiments is presented. The approach minimizes relaxation losses which occur during the transfer of transverse magnetization from 15N to 1HN immediately prior to detection. The utility of the method is demonstrated on a complex of methyl protonated, highly deuterated maltose binding protein (MBP, 370 residues) and β- cyclodextrin. Sensitivity gains relative to previous TROSY schemes of approximately 10 and 20% are noted in HNCO spectra of MBP recorded at 25 and 5 °C, respectively, corresponding to molecular correlation times of 23 and 46 ns.