Reconstitution of Membrane Proteins into Nanodiscs for Single-Particle Electron Microscopy

The structure determination of integral membrane protein (IMP) in lipid environment is particularly challenging. Among emerging methods for exchanging detergent required for IMP purification by original compounds, the use of lipid nanodisc preserves a lipid environment. Compared with the classical method of proteoliposome formation, the nanodisc technology provides a better control of IMP molecules inserted in lipid membrane, therefore giving access to structural methodologies developed for soluble proteins. Here, we present the reconstitution of OprM membrane protein into nanodisc associated with a step of size-exclusion chromatography, an approach applicable to prepare IMPs for subsequent visualization by single-particle electron microscopy.