title: In vitro acetylcholinesterase inhibition by type A botulinum toxin.
abstract: Type A botulinum toxin was studied for its ability to inhibit the action of acetyl-cholinesterase. The chromogenic substrate, indophenyl acetate, was used for assay of enzyme activity. Inhibition of enzyme function was detected through use of both 6.6 x 10(-6) mg (20 ld(50)) and 6.6 x 10(-10) mg (2 x 10(-3)ld(50)) of type A botulinal toxin. Control assays were performed by use of both homologous antitoxin and heterologous antitoxins (types B and E). Enzyme inhibition was effectively prevented by use of homologous antitoxin only. The inhibition noted was specific and reproducible for given substrate, enzyme, and toxin concentrations.
mesh_terms: D000818:Animals; D000992:Antitoxins / Q000494:pharmacology; D002800:Cholinesterase Inhibitors; D003014:Clostridium botulinum; D007461:Iodoacetates / Q000032:analysis; D051379:Mice; D013569:Synapses / Q000187:drug effects; D014118:Toxins, Biological / Q000494:pharmacology*
chemical_list: D000992:Antitoxins; D002800:Cholinesterase Inhibitors; D007461:Iodoacetates; D014118:Toxins, Biological