Approach

We wanted to create a proteolytic enzyme assay based on a linker sequence which contains a cleavage site for proteases, that are characteristic for the venom of different snakes.

Proteins that give off signals when a linker sequence is cleaved, are not a new invention. FRET (Föster resonance energy transfer) has been used for many years in research, to gain a better understanding of protein-protein interactions.

The BioBrick consists of a fusion protein. Inspired by the design of different FRET reporters, our fusion protein contains two larger protein domains, separated by a flexible linker containing one or more substrate sequences. However, unlike FRET reporters, where fluorescent proteins make up the two larger domains, the two large protein domains in our biosensor are a chromoprotein domain and a binding domain. The linker between the two domains is designed to contain the specific cleavage sites found through screening methods.