Ecotin is a broad range serine protease inhibitor, which formshomodimers. The C-terminal region contains the dimerisationmotif [2]. Interestingly, the binding sites show a fluidity ofprotein contacts binding sites show a fluidity of proteincontacts derived from ecotin's innate flexibility in fittingitself to proteases while [4,5]. Ecotin Ecotin