Solution NMR studies of polytopic α-helical membrane proteins.

NMR spectroscopy has established itself as one of the main techniques for the structural study of integral membrane proteins. Remarkably, over the last few years, substantial progress has been achieved in the structure determination of increasingly complex polytopical α-helical membrane proteins, with their size approaching ∼100kDa. Such advances are the result of significant improvements in NMR methodology, sample preparation and powerful selective isotope labelling schemes. We review the requirements facilitating such work based on the more recent solution NMR studies of α-helical proteins. While the majority of such studies still use detergent-solubilized proteins, alternative more native-like lipid-based media are emerging. Recent interaction, dynamics and conformational studies are discussed that cast a promising light on the future role of NMR in this important and exciting area.