Structural features of the botulinum neurotoxin molecule that govern binding and transcytosis across polarized human intestinal epithelial cells.

摘要: Experiments were done to help localize the minimum essential domain within botulinum toxin molecule that is necessary for binding and transport across human gut epithelial cells. The data demonstrated neurotoxin alone, in absence of auxiliary proteins, undergoes transcytosis. by itself was examined single chain (unnicked serotype B) dichain (nicked B, nicked A) forms, all displayed ability bind penetrate barriers. In addition, molecules oxidized reduced states, again forms transported. To further define domain, experiments with two fragments: 1) heavy chain, which derived from native toxin, 2) carboxy-terminal portion generated recombinant techniques. Interestingly, both fragments fully competent crossing These suggest a polypeptide could be used as carrier other related experiments, physiological (i.e., potassium depletion) pharmacological chlorpromazine) manipulations implicate clathrin-coated pits/vesicles structures responsible endocytosis toxin.