CELL-BASED FLUORESCENCE RESONANCE ENERGY TRANSFER (FRET) ASSAYS FOR CLOSTRIDIAL TOXINS

摘要

The present invention provides a method of determining clostridial toxinactivity by (a) contacting with a sample a cell containing a clostridial toxinsubstrate that includes a donor fluorophore; an acceptor having an absorbancespectrum overlapping the emission spectrum of the donor fluorophore; and aclostridial toxin recognition sequence containing a cleavage site thatintervenes between the donor fluorophore and the acceptor, where resonanceenergy transfer is exhibited between the donor fluorophore and the acceptorunder the appropriate conditions; (b) exciting the donor fluorophore; and (c)determining resonance energy transfer of the contacted cell relative to acontrol cell, where a difference in resonance energy transfer of the contactedcell as compared to the control cell is indicative of clostridial toxinactivity.