Why membrane proteins?
Membrane proteins represent almost a quarter of all proteins within living cells. They direct and regulate a wide range of essential functions, being responsible for such diverse process as inter- and intracellular communication, transport of nutrients and generation of energy. Their vital nature is reflected by the fact that up to 70% of current drug targets are membrane proteins. For G-Protein Coupled Receptors, for instance, this represents a multi-billion dollar market. Despite their obvious pharmaceutical importance, our understanding of membrane protein function at an atomic level remains rudimentary. Detailed information about the spatial structure – a prerequisite for modern rational drug design – is rare for membrane proteins.
The key to structure determination of membrane proteins is the production and purification of sufficient quantities of functional protein.