Dimer dissociation of the pore-forming toxin aerolysin precedes receptor binding
The pore-forming toxin aerolysin is secreted by Aeromonas hydrophila as an inactive precursor. Based on chemical cross-linking and gel filtration, we show here that proaerolysin exists as a monomer at low concentrations but is dimeric above 0.1 mg/ml. At intermediate concentrations, monomers and dimers appeared to be in rapid equilibrium. All together our data indicate that, at low concentrations, the toxin is a monomer and that this species is competent for receptor binding. In contrast, a mutant toxin that forms a covalent dimer was unable to bind to target cells.
Keywords: Animals ; Bacterial Toxins/*chemistry/genetics/*metabolism ; Cell Line ; Chromatography ; Gel ; Cricetinae ; Cross-Linking Reagents ; Dimerization ; Mutation ; Pore Forming Cytotoxic Proteins ; Receptors ; Cell Surface/*metabolism
Department of Biochemistry, University of Geneva, 30 quai E. Ansermet, 1211 Geneva, Switzerland.
Record created on 2009-01-30, modified on 2016-08-08