Figure 3.

N213, N62 and Ab63 have antigen-binding affinities/bivalent avidities intermediate between FB11 and Ab52. (a) Biacore analysis of the binding of soluble Francisella tularensis O-antigen core (OAgC) to immobilized N213 and N62. Due to very fast off rates, the K_Ds were calculated based on the steady-state binding parameters. (b) Biacore analysis of the binding of soluble Ab63 to immobilized F. tularensis lipopolysaccharide (LPS). Ab52, captured on anti-mouse IgG-coated chips, was used to capture F. tularensis LPS, which was then probed with 0–13 nm of Ab63. Assays were performed by Precision Antibody (Columbia, MD). The axis labels on the original company graphs in (b) were relabelled for visibility.