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P2015
A Novel Non-Fluorescent Quencher Dye Quenching a Broad Range of Fluorophores & Its Implementation in Protease Activity Assays
Presenter Xinzhan Peng, LI-COR Bioscience, USA
Additional Authors: Garrick Little, Bill Volcheck, Dan Draney
We have developed a novel, non-fluorescent, quencher dye, i.e. IRDye QC-1, that can efficiently quench fluorescence from a broad range of fluorophores, e.g. from visible (~500 nm wavelength) to the near infrared range (~800 nm wavelength) in fluorescence resonance energy transfer (FRET) systems. The quencher and various fluorophores were conjugated to GDEVDGAK peptide, a Caspase-3 substrate. The fluorescence quenching efficiencies observed for IRDye QC-1 are 97.5% for fluorescein, 98.1% for Cy3, 97.9% for Cy5, 98.8% for IRDye 680, 98.8% for IRDye 700DX and 98.7% for IRDye 800CW based on the fluorescence intensity increase after complete cleavage of peptides by Caspase-3. IRDye QC-1 is a water soluble, mono-reactive NHS ester dye which can be used to label peptides, proteins or nucleic acids, etc. through the amine group on such molecules. The use of IRDye QC-1 in fluorogenic protease activity assays has been successfully demonstrated with protease activity assays for HIV-1 protease, BACE-1 and Caspase-3.