Structural Analysis of Membrane Proteins

Membrane proteins constitute a large group of proteins that have structurally distinct differences from soluble proteins, but are substantially underrepresented in structure databanks.
 
We are therefore working on different classes of membrane proteins that are responsible for the controlled transport of nutrients or drugs across the lipid bilayer, such as ABC transporters and other different types of transporters like representatives of the resistance-nodulation-division family.

The preparation of diffraction quality crystals remains the major bottleneck in the structural analysis of membranes proteins by X-ray crystallography. For that reason we use crystallization chaperones (DARPin or scFv) as auxiliary proteins that bind to and increase the crystallization probability of a target molecule of interest. Such chaperones reduce conformational heterogeneity and extend surfaces predisposed to forming crystal contacts.

Depicted is the crystal structure of a complex between AcrB and a DARPin.