Time-Shared X(ω ₁ )-Half-Filter for Improved Sensitivity in Subspectral Editing

Experiments with X-half-filter elements allow the separation of the resonances from protons bound and unbound to a spin X into different subspectra. This Communication presents a modified half-filter element where the filter delay is simultaneously used for chemical shift labeling and scalar coupling evolution in a semi-constant time experiment. The filter element is demonstrated with a ¹ H NOESY spectrum of a 28.5-kDa 2:1 complex between the uniformly ¹³ C-labeled N-terminal domain of Escherichia coli arginine represser and operator DNA.