Sensitivity boosts by the CPMAS CryoProbe for challenging biological assemblies

J Magn Reson. 2020 Feb;311:106680. doi: 10.1016/j.jmr.2019.106680. Epub 2019 Dec 23.

Abstract

Despite breakthroughs in MAS NMR hardware and experimental methodologies, sensitivity remains a major challenge for large and complex biological systems. Here, we report that 3-4 fold higher sensitivities can be 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 that are otherwise time-prohibitive, such as 2D 15N-15N proton-driven spin diffusion and 15N-13C 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 applications, especially for biological systems suffering from low intrinsic sensitivity and at physiological temperatures.

Keywords: Biological assemblies; CryoProbe; MAS NMR; Magic angle spinning.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Capsid Proteins / chemistry
  • Carbon / chemistry
  • Cold Temperature
  • Escherichia coli / chemistry
  • Fungi / chemistry
  • HIV-1 / chemistry
  • Humans
  • Hydrogen Cyanide / chemistry*
  • Indicators and Reagents
  • Kinesins / chemistry
  • Microscopy, Electron, Transmission
  • Microtubules / chemistry
  • Microtubules / ultrastructure
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Prion Proteins / chemistry
  • Sensitivity and Specificity
  • Temperature

Substances

  • Capsid Proteins
  • Indicators and Reagents
  • KIF5B protein, human
  • Prion Proteins
  • Hydrogen Cyanide
  • Carbon
  • Kinesins