An efficient 1H/31P double-resonance solid-state NMR probe that utilizes a scroll coil

Abstract

The construction and performance of a scroll coil double-resonance probe for solid-state NMR on stationary samples is described. The advantages of the scroll coil at the high resonance frequencies of 1 H and 31 P include: high efficiency, minimal perturbations of tuning by a wide range of samples, minimal RF sample heating of high dielectric samples of biopolymers in aqueous solution, and excellent RF homogeneity. The incorporation of a cable tie cinch for mechanical stability of the scroll coil is described. Experimental results obtained on a Hunter Killer Peptide 1 (HKP1) interacting with phospholipid bilayers of varying lipid composition demonstrate the capabilities of this probe on lossy aqueous samples.

Optimization of purification and refolding of the human chemokine receptor CXCR1 improves the stability of proteoliposomes for structure determination

“…The homebuilt 1 H/ 15 N double-resonance probe had 5 mm inner diameter solenoid coil tuned to the 15 N frequency, and an outer MAGC coil tuned to the 1 H frequency [42]. The 31 P solid-state NMR spectra were obtained using a homebuilt 1 H/ 31 P double-resonance probe equipped with double-tuned scroll coil [43]. The one-dimensional 31 P NMR spectra were obtained by direct excitation with a single pulse using a 6 s recycle delay; 64 scans were signal averaged with a 10ms acquisition time for each spectrum.…”

Experimental and numerical examination of eddy (Foucault) currents in rotating micro-coils: Generation of heat and its impact on sample temperature

“…Under the initial MACS set-up significantly greater heating of the sample, than due to friction, was observed [26]. Much attention -notably pertaining to NMR of biological molecules in high ionic-strength solutionshas recently been given to the issue of radio-frequency induced sample heating [31][32][33]. Although, the heating observed for MACS arises through a very different mechanism, the magnitude of the heating is at least as large, and thus will present a similar barrier to implementation for such samples.…”

Construction of 1

“…19,20 For these reasons, a specific probe with high efficiency and high capability is required to study these biological samples using solid-state NMR, and several probe designs have been developed in recent studies to improve their efficiency. 21,22 In this paper, we present the optimized design, construction, and efficiency of a 400 MHz wide-bore (WB) N 2D SAMMY spectra from a single crystal and membrane protein in oriented phospholipid bicelles were successfully obtained using this home-built solidstate NMR probe at 400 MHz.…”