Experimentally, ostreolysin was found to bind in a β -sheet conformation and then unfold into an α-helical structure following permeabilization of target vesicles [41]. Similarly, unfolding of ostreolysin from a β-sheet conformation to α -helical structure prior to interacting with target cells resulted in the loss of lytic activity [38]. These studies demonstrate that the β-sheet conformation is an important prerequisite for initial ligand recognition on target cells that results in eventual permeabilization