Patent ID: 7425425

Claim:
A method for detecting an enzyme-catalyzed cleavage reaction, comprising the following steps: a) providing a modular chemical compound as a substrate for the enzyme comprising covalently linked modules X, Y, and Z having sequence motif: i) Z-X-Y or ii) Y-X-Z, wherein Z comprises a module which is inert with respect to the enzyme-catalyzed cleavage reaction; X comprises a module having n cleavage sites which can be cleaved by the enzyme-catalyzed cleavage reaction into at least two cleavage products X 1 and X n+1 , respectively, n being an integer ≧1; and Y comprises a fluorescent reporter module; b) incubating the compound with the enzyme to form at least two cleavage products, the at least two cleavage products comprising: i) Z-X 1 and X n+1 -Y, wherein the molecular weight of the cleavage product comprising Z-X 1 is at least fifty percent of the total molecular weight of the substrate, or ii) Y-X 1 and X n+1 -Z, wherein the molecular weight of the cleavage product comprising X n+1 -Z is at least fifty percent of the total molecular weight of the chemical compound; and c) detecting the enzyme-catalyzed cleavage reaction by determining the cleavage product containing the reporter module Y, using molecular-weight-sensitive fluorescence spectroscopy.