Adhesion of Dami cell transfectants to type I (Horm) fibrillar collagen. Dami cells transfected with WT GPVI, N92A, S94A, or L95H were incubated in wells of microtiter plates coated with type 1 (Horm fibillar collagen). Adherent cells were quantitated as described in “Materials and methods.” The results represent the average of 3 independent experiments. Following the precedent set in previous reports where GPVI-mediated adhesion to collagen was measured,^17,18  the adhesion of Dami cells transfected with WT GPVI was set as maximal in each experiment, and the results for each mutant GPVI transfectant were then expressed as percent of maximal WT adhesion. The average percent of WT adhesion (± 1 SD) for all 3 experiments is represented in panels A through C. (A) Adhesion in the presence of 2 mM CaCl₂ plus 1 mM MgCl₂. (B) Same as panel A, except Dami transfectants were incubated with 6F1 monoclonal antibody (20 μg/mL) for 60 minutes at ambient temperature prior to the onset of the adhesion assay. (C) Adhesion in the presence of 2 mM EDTA. Error bars represent 1 SD.