Journal of Physical Chemistry B, Vol.117, No.46, 14336-14344, 2013
Photophysics and Release Kinetics of Enzyme-Activatable Optical Probes Based on H-Dimerized Fluorophores on Self-Immolative Linkers
A series of activatable optical probes for the model enzyme penicillin G amidase based on intramolecular formation of non-fluorescent H-dimer between two identical dyes were synthesized. The probes are based on a selfimmolative linker, which allows positioning both dyes in close spatial proximity to ensure efficient quenching of probes with absorption and fluorescence emission in the near-infrared (NIR) range. A detailed photophysical investigation of the novel optical probes led to a revision of a previously anticipated quenching mechanism and revealed their potential for optimizing the performance of activatable probes based on H-dimer formation. A kinetic analysis indicated that the fluorescence progress curves can be used to qualitatively extract enzyme kinetic parameters.