Adhesion of α_Mβ₂-expressing cells to Pg and its derivatives. The α_Mβ₂-expressing cells were added to wells coated with different concentrations of Glu-Pg, Lys-Pg, and Pm (A) or the N-terminal fragment of Glu-Pg (B). Pm was inactivated with 2 mM PMSF for 15 minutes at 22° C. Some cells were preincubated with 40 μg/mL mAb 44a for 20 minutes at 22° C before cell aliquots were added to microtiter plates coated with the N-terminal Pg fragment. Adhesion was quantitated as described in the legend to Figure 2. Results are the total numbers of adherent cells and the mean ± SE values of 4 to 7 individual experiments.