A hierarchy of protein motions: Functioning proteins are not static but explore complex conformational energy landscapes. Lewandowski et al. used multinuclear solid-state nuclear magnetic resonance experiments to measure protein motion over a broad range of temperatures and time scales. Above 160 K there was a strong coupling between solvent and protein motion. The hierarchy of motions as the temperature increased revealed the dynamic modes that relate solvent, sidechain, and backbone motion. Science , this issue p. 578

Nuclear magnetic resonance (NMR) is one of the most powerful analytical techniques currently available, with applications in fields ranging from synthetic chemistry to clinical diagnosis. Due to the size and cost of high-field spectrometers, NMR is generally considered to be ill-suited for industrial environments and field work. This conventional wisdom is currently being challenged through the development of NMR systems that are smaller, cheaper, more robust and portable. Despite remarkable progress in this area, potential applications are often limited by low sensitivity. Hyperpolarisation techniques have the potential to overcome this limitation and revolutionise the use of compact NMR. This review describes the state-of-the-art in NMR hyperpolarisation and presents promising examples of its application to compact NMR. Both the benefits and challenges associated with the different hyperpolarisation approaches are discussed and applications where these technologies have the potential to make a significant impact are highlighted

Benchtop NMR spectrometers operating with low magnetic fields of 1–2 T at sub-ppm resolution show great promise as analytical platforms that can be used outside the traditional laboratory environment for industrial process monitoring. One current limitation that reduces the uptake of benchtop NMR is associated with the detection fields’ reduced sensitivity. Here we demonstrate how para-hydrogen (p-H₂) based signal amplification by reversible exchange (SABRE), a simple to achieve hyperpolarization technique, enhances agent detectability within the environment of a benchtop (1 T) NMR spectrometer so that informative ¹H and ¹³C NMR spectra can be readily recorded for low-concentration analytes. SABRE-derived ¹H NMR signal enhancements of up to 17 000-fold, corresponding to ¹H polarization levels of P = 5.9%, were achieved for 26 mM pyridine in d₄-methanol in a matter of seconds. Comparable enhancement levels can be achieved in both deuterated and protio solvents but now the SABRE-enhanced analyte signals dominate due to the comparatively weak thermally-polarized solvent response. The SABRE approach also enables the acquisition of ¹³C NMR spectra of analytes at natural isotopic abundance in a single scan as evidenced by hyperpolarized ¹³C NMR spectra of tens of millimolar concentrations of 4-methylpyridine. Now the associated signal enhancement factors are up to 45 500 fold (P = 4.0%) and achieved in just 15 s. Integration of an automated SABRE polarization system with the benchtop NMR spectrometer framework produces renewable and reproducible NMR signal enhancements that can be exploited for the collection of multi-dimensional NMR spectra, exemplified here by a SABRE-enhanced 2D COSY NMR spectrum.