There are 1.7% coordinate files from membrane proteins deposited in the protein data bank. 20-30% of all ORFs genomic-wide are predicted to encode membrane proteins and more than 50% drug targets are membrane proteins. A major technical hurdle is to obtain conformationally homogeneous, stable and active pure proteins in sufficient amount. Driven by biological questions, meaningful structural information of membrane proteins and membrane protein complexes have been obtained using X-ray crystallography, Small-Angle X-ray Scattering (SAXS), cryo-Electron Microscopy (cryo-EM) and X-ray Free Electron Laser (XFEL). The study of membrane proteins will be further discussed.


Xiaodan Li is a membrane protein biochemist and structural biologist. She studied biology and biotechnology at the University of Beijing and Zürich, and got her PhD at the ETH Zürich Institute of Microbiology, Switzerland. She did her postdoctoral research at the Rockfeller University and Columbia University in New York. She has established the membrane protein structure biology group at Paul Scherrer Institute since 2002. Her research lab focuses on: 1. Functional expression of mammalian membrane protein in milligram amount using protein engineering; 2. Structure studies of voltage/ligand-gated channels and G-Protein Coupled Receptors (GPCRs) with 3D and 2D crystals using X-ray crystallography, cryo-EM and XFEL; 3. Identification and characterization of human disease-related membrane protein complexes, involved in energy conservation and signalling transduction by mass spectrometry, SAXS and cryo-EM and Total Internal Reflection Fluorescence microscopy (TIRF); 4. Development of nanomaterial tools for detecting membrane protein conformational changes in the lipid bilayer aiming for time-resolved studies using XFEL.