Simultaneous measurement of 1H-15N, 1H-13C', and 15N-13C' dipolar couplings in a perdeuterated 30 kDa protein dissolved in a dilute liquid crystalline phase

Experiments were performed to measure the dipolar couplings of 1H-15N, 1H-13C' and 15N-13C' in a perdeuterated protein under high magnetic field conditions. Analysis of the data revealed the strengthening of 15N line-narrowing through the use of relaxation interference between 15N-1H and 15N chemical shift anisotropy. Findings suggested that the measurement of small heteronuclear dipolar couplings can extend the limit of protein structure determination by nuclear magnetic resonance.