Dynamic nuclear polarization

The weak point of most NMR methods is the relatively low sensitivity of the method, compared to other biophysical techniques. This results in the requirement for relatively large sample sizes and long acquisition times. Ongoing develpments in NMR hardware and methodology aim at substantial sensitivity improvements, for instance through the application of dynamic nuclear polarization (DNP) [1,2]. This technique uses the inherently (much!) larger polarization on electrons to enhance the nuclear NMR signals. Various experimental implementations aimed at biological NMR are described in two recent review articles [2,3]. This includes the application of low temperature DNP for magic angle spinning applications on biological solids, as pioneered in the lab of Robert Griffin, and now also commercially available. Such experiments for example allowed a 120-fold enhancement for GNNQQNY nanocrystals (an amyloid forming peptide fragment of yeast prion protein Sup35p; see also here)[1].

References

1. Van der Wel, P.C.A. et al. (2006)  "Dynamic nuclear polarization of amyloidogenic peptide nanocrystals: GNNQQNY, a core segment of the yeast prion protein Sup35p." J. Am. Chem. Soc. 128:10840-10846 *
2. Barnes et al. (2008) "High field dynamic nuclear polarization for solid and solution biological NMR" App. Magn. Reson. 34(3-4) 237-263 *
3. Maly et al. (2008) "Dynamic nuclear polarization at high magnetic fields"  J. Chem. Phys.  128(1): 052211 *