Spin-State-Selective Excitation. Application for E.COSY-Type Measurement of J_HHCoupling Constants

A new pulse sequence element, spin-state-selective excitation (S³E), is introduced and combined with E.COSY-type techniques for measurement of ¹H-¹H J coupling constants, (S³E) edits the two resonances of a doublet prior to an evolution period of a multidimensional experiment and results in a subspectrum for each resonance, Due to this editing the large heteronuclear one-bond coupling constants normally exploited for separation of submultiplets in E.COSY-type experiments can be suppressed in experiments employing (S³E). Hence there is a concomitant effective increase in resolution, Apart from pulse imperfections and relaxation during a delay (4J)^-1 S³E causes no loss of sensitivity in comparison to conventional experiments. Experimental confirmation is done using the protein RAP 17-97 (N-terminal domain of alpha(2)-macroglobulin receptor associated protein). © 1997 Academic Press.