Dynamics of Membrane Proteins

Transmembrane proteins inhabit a highly asymmetric environment that is, to a first approximation, two-dimensional. Many of them serve to transmit information between aqueous compartments, while others serve as conduits for the transport of material between compartments. In serving these functions they have to adopt at least two stable structures and rapidly interconvert between them. The paucity of atomic resolution structures has been limiting in elucidating the mechanisms by which these proteins carry out their functions. However, this century has seen the determination of the three-dimensional structures of a number of membrane proteins, leading to the start of an understanding of the dynamics displayed by them within the bilayer. Without attempting to be exhaustive, we provide illustrative examples of dynamics in membrane proteins and review their underlying mechanisms as they insert, fold and function in biological membranes.