Sensitivity boosts by the CPMAS CryoProbe for challenging biological assemblies

Abstract

Despite breakthroughs in MAS NMR hardware and experimental methodologies sensitivity remains a major challenge for large and complex biological systems. Here, we report 3-4 fold higher sensitivities obtained in heteronuclear-detected experiments, using a novel HCN CPMAS probe, where the sample coil and the electronics operate at cryogenic temperatures, while the sample is maintained at ambient temperatures (BioSolids CryoProbe™). Such intensity enhancements permit recording 2D and 3D experiments for large assemblies that are otherwise time-prohibitive, such as 2D 15 N-15 N proton-driven spin diffusion and 15 N-13 C double cross polarization to natural abundance carbon experiments. The benefits of CPMAS CryoProbe-based experiments are illustrated for assemblies of kinesin Kif5b with microtubules, HIV-1 capsid protein assemblies, and fibrils of human Y145Stop and fungal HET-s prion proteins -demanding systems for conventional MAS solid-state NMR and excellent reference systems in terms of spectral quality. We envision that this probe technology will be beneficial for a wide range of Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Significant, 3-4 fold sensitivity gains are obtained experiments with a novel CPMAS CryoProbe.The benefits of CPMAS CryoProbe are demonstrated in heteronuclear-detected 2D and 3D experiments on five challenging biological assemblies.High-quality 2D NN and NCA/NCO spectra are obtained on U-15 N-CA tubular capsid assembly containing carbons at natural abundance.

Gut bacteria are essential for normal cuticle development in herbivorous turtle ants

“…The 15 N spectra were referenced using L-tyrosine ( δ = 40.4 ppm). The 1 H– 15 N– 13 C double CP-MAS experiment was carried out on a Bruker Advance Neo spectrometer operating at 14.1 T ( 13 C Larmor frequency of 150.9 MHz) using a 3.2 mm Bruker CP-MAS CryoProbe TM 32 . The MAS frequency was 11 kHz, and the 1 H– 15 N and 15 N– 13 C contact times were 1.5 and 7 ms, respectively.…”

Probing short and long‐range interactions in native collagen inside the bone matrix by BioSolids CryoProbe

“…In the future, multidimensional 1 H detected solid‐state NMR experiments using BioSolids CryoProbe (noninvasive) would be more advantageous in elucidating the atomic‐scale structure along with the dynamics of the biological system. Hence, all these developments such as proton‐detected solid‐state NMR experiments, CPMAS BioSolids CryoProbe, [ 37 ] and MAS‐DNP‐based solid‐state NMR experiments can complement each other to get structural and dynamical details of biological systems in natural abundance.…”

“…Cryogenically cooling the RF coil and preamplifier electronics leads to a boost in S/N by 3–4 folds and hence faster data acquisition by at least an order of magnitude while keeping the sample in its original composition along with its natural line width. [ 37 ]…”

Efficient incorporation and protection of lansoprazole in cyclodextrin metal-organic frameworks

“…Hence, the cryoprobe technology is so far the only technology that allows probing the state of a low API content in formulations that are not amenable to DNP-MAS NMR. Note that the CP-MAS CryoProbe has been used so far for biomolecules (Hassan et al, 2020), and we reported here its first use in the field of materials science.…”

“…10,240 and 75,776 transients were accumulated for LPZ and LPZ loaded CD-MOF, respectively. Similar 15 N CPMAS NMR spectra were recorded at 8 kHz MAS frequency on a Bruker 600 SB NMR spectrometer using a novel cryogenically cooled 3.2 mm HCN CPMAS probe (Biosolids Cry-oProbe™) (Hassan et al, 2020). 528 and 122 888 transients were accumulated for LPZ and LPZ loaded CD-MOF, respectively.…”