The Daily Bulletin Archive

Please join the Chemistry and Physics departments as Ozlem Dilek, assistant professor in the Department of Biochemistry, School of Medicine, at Istanbul Kemerburgaz University, presents "Synthesis of Bioorthogonal Fluorescent Probes: Turn-on Targeting and Imaging of Proteins in Live Cells" on Thursday, March 9, at 12:30 p.m. in Science and Mathematics Complex 173. All students, staff, and faculty are welcome.

Abstract
Bioorthogonal site-specific chemical reaction to label biomolecules in vitro and in living cells is one of the most powerful tools in chemical biology. In bioorthogonal chemistry, aldehyde or ketone functional groups can be attached to peptides and proteins. Reactive pairs frequently used for chemical conjugation are aldehydes/ketones with hydrazine/amine derivatives. The specific site of a protein can also be monitored by novel fluorophores using click chemistry at physiological conditions and temperature. In this research, we have synthesized a library of fluorophores that can react with the model compound of aldehyde on protein at or near physiological conditions to form a stable conjugated product. The final product shows a significant increase in fluorescence quantum yield upon covalent bond formation. Although the reaction is generally specific for the two components, even in a cellular environment, the reaction is very slow under physiological conditions. We have also found that adding an ortho-phosphate group to an aromatic aldehyde increases the reaction rate by an order of magnitude. An added benefit is that phosphate enhances the aqueous solubility of the reagent and its hydrazone product. This rapid bioorthogonal reaction with suitable probes should therefore be potentially a very useful strategy for site-specific chemical ligations to study and image complex cellular processes in biological systems.