A deeper analysis of the epitope/paratope of PLY-5, a mouse monoclonal antibody which recognises the conserved undecapeptide tryptophan-rich loop (ECTGLAWEWWR) of bacterial cholesterol-dependent cytolysins

► An immunoscreening of amino acid substitution analogues in the undecapeptide was performed. ► The second Trp and the Arg residues were identified as essential in the PLY-5 epitope. ► Antibody modelling and docking simulations provided support for these findings. ► For epitope recognition by the antibody, the Trp-rich loop should flip out, resembling the mechanism for membrane insertion.