Nanobodies to study protein conformational states.

Because of their small size and their beneficial biochemical and economic properties (size, affinity, specificity, stability, production cost), nanobodies are now increasingly used for routine and more innovative applications in research, biotechnology, and medicine. As they provide access to conformational epitopes in concave and hinge regions, nanobodies are also increasingly applied in structural biology to freeze dynamic proteins into single functional conformations. X-ray crystallography can then be used to determine the structures of different stills of the same moving biomolecule. Conformational nanobodies can also be introduced as intrabodies inside living cells as conformational biosensors for spatiotemporal analysis. By engineering these nanobodies in several ways, conformational nanobodies are now also amenable to single particle cryo-EM or to drive better-focused drug discovery.