Fluorescence polarization assays for determining clostridial toxin activity

摘要

The present invention provides a method of determining the presence or activityof a clostridial toxin by (a) treating with a sample, under conditions suitablefor clostridial toxin protease activity, a clostridial toxin substrate whichincludes a fluorophore; a bulking group; and a clostridial toxin recognitionsequence containing a cleavage site that intervenes between the fluorophoreand the bulking group; (b) exciting the fluorophore with plane polarized light;and (c) determining fluorescence polarization of the treated substrate relativeto a control substrate, where a change in fluorescence polarization of the treatedsubstrate as compared to fluorescence polarization of the control substrateis indicative of the presence or activity of the clostridial toxin.