Figure 5.

Kinetics of dissociation and mechanical strength of transient tethers of P- or L-selectin-expressing cells to wild-type or single-Tyr PSGL-1. (A and B) Representative first-order dissociation kinetics for transient tethers of L1–2 cells expressing P- or L-selectin to each PSGL-1 construct at the indicated wall shear stress. For each set of tether lifetimes, the line is the least squares fit, and the slope is −k_off for the selectin–PSGL-1 bond. (C and D) Effect of increased wall shear stress and force on the tether bond on dissociation kinetics of P- or L-selectin with wild-type or single-Tyr PSGL-1. Each group of points represents a single wall shear stress from each of five independent experiments. The points were displaced horizontally so that all points could be seen. The data were fit to the Bell equation (24).