Clostridial Assay

In vitro Assay of L Chain Activity. Since the elucidation of the molecular mechanisms of all clostridial neurotoxins, it has become convenient to test the proteolytic activity of the L chain in vitro. For this purpose, L chain or reduced di-chain toxin is incubated with substrate protein. The cleavage products are then separated by SDS-PAGE and analyzed by immunoblotting or autoradiography. 

Abdominal ultrasound Barium enema Barium swallow Carcinoembiyonic antigen Clostridial toxin assay Colonoscopy... 

Artificial donors include the viologen dyes and hydrosulfite. Methyl viologen can replace clostridial Fd or Fid. Oxidation of the monomer of poly-)S-hydroxybutyrate, a major component of soybean nodule bac-teroids, has been coupled to N2ase to give very low activity via a complex system composed of a dehydrogenase, NAD a diaphorase, and a viologen dye 14). Hydrosulfite is the most useful donor for in vitro N2ase assays since it can be used in substrate amounts in contrast to all other natural and artificial donors (22). 

Steward, L. E. Femandez-Salas, E. Aoki, K. R. Fluorophore-labeled peptides and FRET assays for clostridial toxins. U.S. Pat. Appl. Publ. US 2003143651, 2003 Chem. Abstr. 2003,139,129339. 

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