A step-by-step protocol for capturing conformational snapshots of ligand gated ion channels by single-particle cryo-EM

Capturing conformational snapshots by single-particle cryo-EM facilitates the analysis of ligand binding and activation mechanisms for ion channels and other receptor complexes. Here, we present a protocol to capture intermediate states of nanodisc-reconstituted TRPV1. This protocol covers sample preparation, data acquisition, and image processing with focuses on the symmetry expansion and focused 3D classification. This protocol can be adapted to different proteins and samples. For complete details on the use and execution of this protocol, please refer to Zhang et al. (2021).