Solid-state NMR approaches to study protein structure and protein-lipid interactions.

Solid-state NMR spectroscopy has been developed for the investigation of membrane-associated polypeptides and remains one of the few techniques to reveal high-resolution structural information in liquid-disordered phospholipid bilayers. In particular, oriented samples have been used to investigate the structure, dynamics, and topology of membrane polypeptides. Much of the previous solid-state NMR work has been developed and performed on peptides, but the technique is constantly expanding towards larger membrane proteins. Here, a number of protocols are presented describing among other the reconstitution of membrane proteins into oriented membranes, monitoring membrane alignment by (31)P solid-state NMR spectroscopy; investigations of the protein by one- and two-dimensional (15)N solid-state NMR; and measurements of the lipid order parameters using (2)H solid-state NMR spectroscopy. Using such methods solid-state NMR spectroscopy has revealed a detailed picture of the ensemble of both lipids and proteins and their mutual interdependence in the bilayer environment.