Phage display of proteases and macromolecular inhibitors.

We describe methods for displaying the protease trypsin and the macromolecular protease inhibitor ecotin on the surface of filamentous phage. Our strategy for selecting variant ecotins against target proteases is also described. We believe that the two proteins that have been displayed serve as ideal models for studying molecular recognition in detail. The ability to search efficiently through a large number of variant proteins for desired properties using phage display technology and the in vitro selection methods described opens a new avenue for studying protein-ligand interactions, as well as creating proteins with novel functions.