High-resolution epitope mapping by HX MS reveals the pathogenic mechanism and a possible therapy for autoimmune TTP syndrome.

The epitope residues recognized by scFv4-20 were deduced based on hydrogen-deuterium exchange mass spectrometry analysis of peptides produced from acid protease digestion of the amino terminal MDTCS domains of ADAMTS13 in the presence and absence of bound antibody. Deletion of any of the five loops (residues 659-664, 632-639, 608-614, 558-592, and 667-672) that contain the epitope residues abolished binding of scFv4-20.