Monoclonal Antibodies to the C-Terminal Domain of Hemolysin II Bacillus Cereus

Bacillus cereus is an opportunistic Gram-positive anaerobic spore-forming bacterium found in various environmental conditions. One of the pathogenicity factors is hemolytic toxin II, which belongs to the group of β-barrel pore-forming toxins. HlyII B. cereus differs from other β- barrel pore-forming toxins by having a C-terminal extension of 94 amino acid residues. In this work, the binding sites of monoclonal antibodies obtained against recombinant HlyIICTD on the protein surface were determined. Using monoclonal antibodies, it was shown that HlyIICTD interacts with the erythrocyte membrane in a strictly defined manner. The localization of epitopes recognized by monoclonal antibodies suggested that the binding site of HlyIICTD with the membrane is localized in the C-terminal region of HlyIICTD molecule.