Evidence that conformational changes upon the transition of the native to the modified form of vitronectin are not limited to the heparin binding domain.

Vitronectin (Vn) exists in vivo in at least two different conformational states, the native and the modified form, and these forms have different ligand binding properties. To characterize the molecular events associated with this conformational flexibility, modified Vn was analyzed by competitive ELISA using a panel of conformationally sensitive antibodies with known epitopes. These studies provided evidence for major molecular rearrangements upon the transition from the native to the modified form that are not limited to the C-terminal heparin binding domain, but also occur in the N-terminal part of the molecule.