From Sensitivity to Resolution: Transforming DNP MAS NMR of biosolids

Dynamic nuclear polarisation (DNP) has recently emerged as a transformative technology to address the sensitivity limitation of Nuclear Magnetic Resonance (NMR) spectroscopy.

In the solid-state, hyperpolarisation has the potential to reveal unique insight into the structure of complex biological assemblies such as amyloid fibrils, membrane-embedded proteins, virus capsids or plant cell walls.

However, despite key pioneering studies, several challenges must be resolved before DNP Magic Angle Spinning (MAS) NMR can be widely adapted as a routine analytical approach for studying biomolecules.

The primary bottleneck is the resolution of 13C and 15N DNP enhanced NMR spectra of solid-state biomolecules which is compromised by severe line broadening at the cryogenic temperatures at which DNP experiments are performed. The second limitation is the absence of robust site-specific assignment strategies.

Leveraging progress in fast MAS and high-field DNP NMR systems, the project will focus on improving spectral resolution through the development of (i) new sample formulations and labeling strategies, (ii) advanced radio-frequency pulse sequences using unique instrumentation at the host laboratory, and (iii) innovative methods for site-specific assignment of backbone and side-chain resonances.

These methods will first be tested on model microcrystalline samples, then applied to complex biological targets like vaccines and fibrillar assemblies.

The proposed work is highly interdisciplinary, connecting biochemical techniques, spin physics, and physical chemistry, and will have a broad impact across fields including structural biology, pharmaceutical science, and materials science.

The methods developed will streamline data collection in biomolecular NMR and push the boundaries of what is currently possible with hyperpolarisation today.

The project will significantly advance both fundamental and applied research, benefiting large communities of chemists and biologists.