Structural and biophysical characterisation of membrane protein-ligand binding (editorial)

A detailed understanding of membrane protein structure and function remains of profound importance on many fronts, not least of which includes drug discovery. In a post-genomic era it is now well established that a sizeable 20–30% of eukaryotic, eubacterial and archaean open reading frames encode integral membrane proteins. Furthermore, membrane proteins constitute approximately 49% of current therapeutic targets in higher organisms, providing evidence of their strong potential as targets for new drugs of the future. A detailed understanding of how agonist and antagonist ligands interact and bindwith membrane protein drug targets is important for the development and refinement of new and novel therapeutics. Although commercially-available drugs targeting membrane proteins have so far been generated mainly through conventionalmeans (high throughput screening, functional assays etc.), the availability of structure-based and/or biophysical techniques for investigating membrane protein–ligand interactions reveals the details of how ligands and potential new drugs bind. The purpose of this Special Issue is to provide a review of some biophysical techniques available for studying membrane protein interactionswith ligands and drugs. It also reviews some of the latest developments inmethods and approaches for structure elucidation, particularly focusing on optimisation of membrane protein crystal growth for structure determination using X-ray crystallography, one of the pre-requisites for structure-based investigations of ligand binding