Is protein deuteration beneficial for proton detected solid-state NMR at and above 100 kHz magic-angle spinning?

¹ H-detection in solid-state NMR of proteins has been traditionally combined with deuteration for both resolution and sensitivity reasons, with the optimal level of proton dilution being dependent on MAS rate. Here we present ¹ H-detected ¹⁵ N and ¹³ C CP-HSQC spectra on two microcrystalline samples acquired at 60 and 111 kHz MAS and at ultra-high field. We critically compare the benefits of three labeling schemes yielding different levels of proton content in terms of resolution, coherence lifetimes and feasibility of scalar-based 2D correlations under these experimental conditions. We observe unexpectedly high resolution and sensitivity of aromatic resonances in 2D ¹³ C- ¹ H correlation spectra of protonated samples. Ultrafast MAS reduces or even removes the necessity of ¹ H dilution for high-resolution ¹ H-detection in biomolecular solid-state NMR. It yields ¹⁵ N, ¹ H and ¹³ C, ¹ H fingerprint spectra of exceptional resolution for fully protonated samples, with notably superior ¹ H and ¹³ C lineshapes for side-chain resonances.
(Copyright © 2017. Published by Elsevier Inc.)