Simultaneous MQMAS NMR Experiments for Two Half-Integer Quadrupolar Nuclei

Slice & Dice: nested spin-lattice relaxation measurements

Spin-lattice relaxation rate (R₁) measurements are commonly used to characterize protein dynamics. However, the time needed to collect the data can be quite long due to long relaxation times of the low-gamma nuclei, especially in the solid state. We present a method to collect backbone heavy atom relaxation data by nesting the collection of datasets in the solid state. This method results in a factor of 2 to 2.5 times faster data acquisition for backbone R₁ relaxation data for the ¹³C and ¹⁵N sites of proteins.

Accelerating 15N and 13C R1 and R1ρ relaxation measurements by multiple pathway solid-state NMR experiments

Magic angle spinning (MAS) Solid-state NMR is a powerful technique to probe dynamics of biological systems at atomic resolution. R₁ and R_1ρ relaxation measurements can provide detailed insight on amplitudes and time scales of motions, especially when information from several different site-specific types of probes is combined. However, such experiments are time-consuming to perform. Shortening the time necessary to record relaxation data for different nuclei will greatly enhance practicality of such approaches. Here, we present staggered acquisition experiments to acquire multiple relaxation experiments from a single excitation to reduce the overall experimental time. Our strategy enables one to collect ¹⁵N and ¹³C relaxation data in a single experiment in a fraction of the time necessary for two separate experiments, with the same signal to noise ratio.