Mapping invisible epitopes by NMR spectroscopy

Defining discontinuous antigenic epitopes remains a substantial challenge, as exemplified by the case of lipid transfer poly-proteins, which are common pollen allergens. Hydrogen/ deuterium exchange monitored by NMR can be used to map epitopes onto folded protein surfaces, but only if the complex rapidly dissociates. Modifying the standard NMR-exchange measurement to detect substoichiometric complexes overcomes this time scale limitation and provides new insights into recognition of lipid transfer polyprotein by antibodies. In the future, this new and exciting development should see broad application to a range of tight macromolecular interactions.