A dual-purpose synthetic colloidal platform for protease mapping: substrate profiling for Dengue and West Nile virus proteases.

In a proof of concept study, we created a small focused fluorescent hexapeptide library onto 14 multiplexed barcoded sets of silica particles to probe the substrate recognition specificity of West Nile and Dengue virus proteases. A flow cytometric analysis demonstrated that the optical signature of each bead population remained distinguishable throughout the solid-phase peptide synthesis and proteolytic assay. As expected, both proteases displayed a narrow specificity for lysine and arginine residues in the P(1) and P(2) substrate positions. This open-ended platform enables the fast and simultaneous identification of peptide substrates and is applicable to other proteases.