FIG 4.

Binding of donor strand-complemented CfaB and CfaE subunits to asialo-GM1. The asialo-GM1 binding of donor strand-complemented subunits and that of negative-control, heat-inactivated subunits were compared in an ELISA-based assay. Purified CfaE subunits (black squares) bound to asialo-GM1, while binding of CfaB (black circles) was no greater than that of negative-control heat-inactivated CfaE and CfaB subunits (gray squares and circles, respectively). Data points are the mean values of three biological repeats, each consisting of three technical repeats, ± the standard error of the mean.