FIG. 2.

Binding of purified ligands to streptococci expressing the M5 and Emm22 proteins. The binding of ¹²⁵I-labeled ligands to the indicated group A streptococcal strains was measured as a function of bacterial number. Fibrinogen (A) and FHL-1 (B) are known to interact specifically with the M5 protein, whereas C4BP (C) and IgA (D) bind to the Emm22 protein. The data presented are based on three independent experiments with triplicate samples. The variation was <5% of the binding, and therefore error bars have not been introduced.