C-Terminal Domain of Bacillus cereus Hemolysin II Is Able to Interact with Erythrocytes

Hemolysin II (HlyII) is one of the pathogenic factors of Bacillus cereus. With respect to the prototype of β-barrel toxins, the α-toxin of S. aureus, this pore-forming protein has a C-terminal domain (CTD) of 94 amino acids. The role of CTD in membrane pore formation and cell lysis is not clear, although removal of this portion of the protein is known to significantly reduce hemolytic activity. A representative panel of monoclonal antibodies against recombinant CTD recognizing full-length HlyII was obtained. Using the obtained monoclonal antibodies, CTD was shown to bind to rabbit red blood cells.