Vimentin binding to hGIIA mutants. (A) hGIIA (WT) or its mutants (0.1 μg/mL) were incubated with PVDF membranes to which 0.5 μg vimentin was immobilized. As positive controls, hGIIA or its mutants (8 ng) were also immobilized onto PVDF membranes. hGIIA and its mutants were then detected by immunoblotting as described in “Materials and methods.” Decreased (left panels) and increased (right panels) binding of hGIIA mutants to vimentin is shown. (B) The ratio between the densitometric quantification of the hGIIA bound to 0.5 μg vimentin and that of 8 ng of the corresponding immobilized hGIIA represents the relative binding of hGIIA to vimentin. Results are presented as percentage of WT and are the means ± SEM of 4 different experiments.