A new proton-nitrogen-15-carbon-13 triple-resonance experiment for sequential assignments and measuring homonuclear Ha-HN vicinal coupling constants in polypeptides
G. Wagner, P. Schmieder, V. Thanabal
J. Magn. Reson. (1991) 93, 436-440
A new design of pulse sequences for the title experiment is described that provides results similar to those from the experiments of G. T. Montelione and G. Wagner (1989,1990), but does not rely on coherence transfer between C and N. They are simpler and significantly more sensitive than the original techniques, so that they can be applied to proteins. An illustrative spectrum for a cyclic hexapeptide is presented. The intraresidue cross peaks have the desired E.COSY-type multiple structure. The homonuclear coupling constant can be measured precisely from the intraresidue cross peak.