Photoreductive uncaging of fluorophore in response to protein oligomers by templated reaction in vitro and in cellulo.

The photoreduction of azide-based immolative linker by Ru(II) conjugates to uncage rhodamine was achieved using different oligomeric protein templates. The generality of the approach was validated with three sets of ligand having varying affinity to their target (biotin, desthiobiotin and raloxifene). The reaction rates of the templated reaction was found to be at least 30-fold faster than the untemplated reaction providing a clear fluorescent signal in response to the protein oligomer within 30 min. The templated reaction was found to also proceed in cellulo and could be used to identify acetyl coenzyme A carboxylase (ACC) in Pseudomonas aeruginosa and human cell lines as well the and estrogen receptor (ER).