Patent ID: 6972182

Claim:
A method of detecting or monitoring the activity of a protease enzyme, comprising the steps of: a) providing a first polypeptide binding domain, and a second polypeptide binding domain, wherein i) at least one of the binding domains comprises a site for protease digestion and wherein said site for protease digestion is located within said first or second polypeptide binding domain; and ii) the first and second binding domains bind to each other such that a detectable signal is generated, and digestion of the binding domains at the site for protease digestion by the protease enzyme results in modulation of the binding of the polypeptides to each other and therefore of the detectable signal; b) allowing the binding domains to bind to each other and induce a detectable signal; c) contacting the binding domains with a protease enzyme; and d) detecting modulation of the detectable signal as a result of the modulation of the binding of the binding domains.