Figure 3.

Diverse patterns of recognition. The 3 anti-LukAB antibodies (SA-13, SA-15, and SA-17) and 2 irrelevant controls (SA-22 and immunoglobulin G) were tested for binding to immobilized LukA monomer (A), LukB monomer (B), or LukAB heterodimer (C). SA-13 and SA-17 bound both the LukA monomer and the LukAB heterodimer, while SA-15 bound only the heterodimer, suggesting that SA-15 binds to a conformational epitope present only after dimerization. None of the antibodies exhibited reduced binding in the presence of a competing antibody, suggesting unique epitopes for each of the 3 antibodies (D). Abbreviations: IgG, immunoglobulin G; mAb, monoclonal antibody.