Scott, D.J. & Plückthun, A. J. Mol. Biol. 425, 662–677 (2013).

Engineering detergent-stable variants of integral membrane proteins would enable many studies, including structural studies, of this important class of proteins. Scott and Plückthun describe a bacterial encapsulation technique that permits selection for detergent-stable membrane proteins from a large mutant library. When encapsulated bacteria expressing the protein of interest are solubilized, the resulting nanocontainer retains (that is, prevents the exit or loss of) the solubilized protein variant and its encoding gene but allows entry of a fluorescently labeled ligand. Detergent-stable variants of the examined protein can then be isolated by iteratively identifying ligand-binding clones. The researchers applied the approach to evolve detergent-stable variants of two G protein–coupled receptors.