Mac-1 binding to iC3b and denatured BSA is not affected by the S1126A mutation. (A) Jβ2.7 transfectants expressing wt CD11b were allowed to bind to wells coated with iC3b at different ligand concentrations (microgram per milliliter of ligand used for coating) for 30 minutes. (B) Adhesion of transfected cells to coated iC3b (6 μg/mL) with or without activation was performed as described in “Materials and methods.” (C) As in panel B, except that denatured BSA (1 mg/mL) was used as a ligand. Error bars represent SD.