Design of 365 nm light-triggered fluorogenic crosslinking via a genetically encoded 3-CF3-p-phenylenediamine-lysine featuring red-shifted photo-defluorination

Abstract

We introduce 3-CF₃-p-phenylenediamine-l-lysine, a genetically encodable photo-defluorination–acyl fluoride exchange ncAA. It features red-shifted activation (311 → 365 nm) for faster photo-defluorination relative to 1^st-generation photo-DAFEx ncAAs, and subsequent Ac-F crosslinking toward R-NH₂ with fluorogenic emission at visible 498 nm. This facilitates capturing and imaging of protein–protein interactions in living systems.