Photoinduced Electron Transfer-Regulated Protein Labeling With a Coumarin-Based Multifunctional Photocrosslinker.

We developed a novel diazirine-based photolabeling agent having a (coumarin-4-yl)methyl ester scaffold, which exhibited multiple photochemical properties of crosslinking, fluorogenicity and cleavage. These properties can be kinetically regulated via photoinduced electron transfer between diazirine and coumarin moieties. The C-O bond of (coumarin-4-yl)methyl ester can be cleaved via photochemical excitation of coumarin moiety, that function has been initially quenched by the diazirine moiety.