Structure-based drug design uses the three-dimensional structure of a target protein to identify functional binding sites and design drug molecules that complement their shape, size, and electrostatic properties. This approach has enabled major advances in medicine, including HIV protease inhibitors, antibiotics, and targeted cancer therapies such as imatinib.

A high-resolution cryo-EM map can still leave important regions unresolved. Here's what missing density may and may not tell you about protein structure, flexibility, and conformational heterogeneity.

Electron paramagnetic resonance (EPR) spectroscopy is one of the most effective methods for studying membrane protein structure and dynamics. Unlike X-ray crystallography and cryo-electron microscopy, which provide static structural snapshots, EPR measures conformational ensembles and molecular motions under native-like conditions. This makes it particularly valuable for investigating GPCRs, ion channels, and membrane transporters involved in drug discovery.