Transposing green fluorescence into the near-IR: Luminogenic redox reporters

ORGN 674

Marlin Halim, mh2336@columbia.edu1, Matthew S. Tremblay, mst2008@columbia.edu1, Steffen Jockusch, sj67@columbia.edu2, Nicholas. J Turro, njt3@columbia.edu1, and Dalibor Sames, sames@chem.columbia.edu1. (1) Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, (2) Department of Chemistry, University of Columbia, Department of Chemistry, Columbia University, 3000 Broadway, mail code 3119, New York, NY 10027
Responsive optical reporters enable direct, continuous probing of enzymatic events in complex environments such as living cells. Luminescent lanthanide complexes are a particularly attractive class of optical reporters owing to their sharp emission lines and long excited state lifetimes. We have developed a near-infrared (NIR) luminescent reporter for the aldo-keto reductase enzyme AKR1C2 by appending a fluorogenic coumarin substrate to a macrocyclic Nd(III) moiety via an alkyl linker. Enzymatic reduction of the ketone functionality on the coumarin affects the energy transfer from the fluorophore to the emissive Nd(III) state, resulting in observed luminescence at 1060 nm. Increasing the tether length dramatically improves the suitability of the complexes as enzyme substrates while maintaining the fidelity of the energy transfer from the coumarin to the lanthanide ion. Importantly, the development of the NIR luminogenic reporter substrates described herein represents a potentially general platform for transposing green fluorescence into the NIR region.

 

Biologically-Related Molecules and Processes
8:00 AM-12:00 PM, Wednesday, August 22, 2007 BCEC -- 258B, Oral

Division of Organic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007