Photocage-Selective Capture and Light-Controlled Release of Target Proteins

Photochemical transformations enable exquisite spatiotemporal control over biochemical processes; however, methods for reliable manipulations of biomolecules tagged with biocompatible photo-sensitive reporters are lacking. Here we created a high-affinity binder specific to a photolytically removable caging group. We utilized chemical modification or genetically encoded incorporation of noncanonical amino acids to produce proteins with photocaged cysteine or selenocysteine residues, which were used for raising a high-affinity monoclonal antibody against a small photoremovable tag, 4,5-dimethoxy-2-nitrobenzyl (DMNB) group. Employing the produced photocage-selective binder, we demonstrate selective detection and immunoprecipitation of a variety of DMNB-caged target proteins in complex biological mixtures. This combined orthogonal strategy permits photocage-selective capture and light-controlled traceless release of target proteins for a myriad of applications in nanoscale assays.