High-resolution NMR of biological solids

Solid-state NMR experiments have recently provided a number of biochemical insights: motionally averaged H-2 lineshapes have shown that the motion of a backbone loop protecting a protein binding site is not ligand gated; isotropic C-13 chemical shifts of freeze-quenched enzyme-ligand intermediates have revealed mechanistic details of reaction pathways; multiple heteronuclear distance determinations have characterized the binding-site geometry of a 46 kDa noncrystalline enzyme complex; and homonuclear recoupling experiments have established that insoluble amyloid fibrils form a pleated beta sheet.