NMR backbone assignment of the Cε4 domain of immunoglobulin E.

Immunoglobulin E (IgE) plays a central role in allergic reactions. IgE is a dynamic molecule that is capable of undergoing large conformational changes. X-ray crystal structures of the Fc region of IgE in complex with various ligands have shown that IgE-Fc can exist in extended and various bent conformations. IgE-Fc consists of three domains: Cε2, Cε3 and Cε4. While the complete NMR backbone assignments of the Cε2 and Cε3 domains have been reported previously, the Cε4 domain has not been assigned. Here, we report the complete backbone assignment of the Cε4 homodimer. Cε4 can be used as a model system to study dynamics and allostery in IgE, as both molecules exist as homodimers and exhibit similar binding properties to a number of ligands.