A monoclonal antibody against tetrodotoxin that reacts to the active group for the toxicity

A monoclonal antibody against tetrodotoxin was produced. Tetrodotoxin coupled with keyhole limpet hemocyanin was used as an immunogen to BALB/c mice. These mice had no clinical signs for the toxicity of tetrodotoxin during the immunization. The reason may be that the guanidyl group of tetrodotoxin which is an important group for the toxicity was hidden by coupling with keyhole limpet hemocyanin. The monoclonal antibody was highly specific for tetrodotoxin and had no cross-reaction to tetrodotoxin derivatives, paralytic shellfish toxins, keyhole limpet hemocyanin and crude proteins from various organs of puffer fish. Also, tetrodotoxin was neutralized in vitro by this antibody. From the fact that the structural difference between tetrodotoxin and anhydro-tetrodotoxin is recognized by this antibody, it was suggested that this antibody reacted with the OH-groups on C-4 and/or C-9 of tetrodotoxin. In addition, the results from immunization and neutralization tests demonstrated that tetrodotoxin became non-toxic even when one of the active groups of tetrodoxin was coupled by a molecule.