Visualizing the nanoscale: protein internal dynamics and neutron spin echo spectroscopy.

The most complex molecular machines are proteins found within cells. Protein dynamics, in particular dynamics on nanoscales, presents us with a novel paradigm for cell signaling: the idea that proteins and protein complexes can communicate directly within themselves to effect long-range information transfer, via coupled domains and correlated residue clusters. This idea has been little explored, in large part because of a paucity of experimental techniques that can address the necessary questions. Here we review recent progress in developing a promising new approach, neutron spin echo spectroscopy.