Fluorogenic label for biomolecular imaging

BIOL 117

Luke D. Lavis, lavis@chem.wisc.edu, Departments of Chemistry and Biochemistry, University of Wisconsin—Madison, 433 Babcock Drive, Madison, WI 53706, Tzu-Yuan Chao, Department of Biochemistry, University of Wisconsin - Madison, 433 Babcock Drive, Madison, WI 53706, and Ronald T. Raines, raines@biochem.wisc.edu, Departments of Chemistry and Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706.
Traditional small-molecule fluorophores are always fluorescent. That attribute can obscure valuable information in biological experiments. We have developed a versatile “latent” fluorophore that overcomes this limitation. At the core of the latent fluorophore is a rhodamine derivative in which one nitrogen is modified as a urea. That modification enables rhodamine to retain half of its fluorescence while facilitating conjugation to a target molecule. The other nitrogen of rhodamine is modified with a “trimethyl lock”, which enables fluorescence to be unmasked fully by a single user-designated chemical reaction. An esterase-reactive latent fluorophore was synthesized in high yield and attached covalently to a cationic protein. Esterase activity in endocytic vesicles and the cytosol educed fluorescence, enabling continuous imaging of endocytosis into live human cells. The modular design of this “fluorogenic label” enables the facile synthesis of an ensemble of small-molecule probes for the illumination of numerous biochemical and cell biological processes.

 

Chemistry and Metabolism
4:30 PM-6:30 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster

Division of Biological Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006