Imaging of Transmembrane Proteins Directly Incorporated Within Supported Lipid Bilayers Using Atomic Force Microscopy

Structural analysis of transmembrane proteins remains a challenge in biology, mainly due to their difficulty in being overexpressed and the required use of detergents that impair different steps of biochemistry classically used to obtain 3D crystals. In this context, we have developed a new technique for protein incorporation within supported lipid bilayers that only requires a few picomoles of protein per assay. Proteins are directly inserted into a detergent-destabilized bilayer that can be imaged in buffer with atomic force microscopy (AFM) allowing structural analysis down to sub-nanometer lateral resolution. In this chapter, we describe the main guidelines for this technique, from the choice of detergent to the requirements for AFM high-resolution imaging.