Fig. 3.

Experimental best-fit results for bond lifetime τ(F) versus force F for selectins. A and B correspond to the receptor P-selectin (Psel) while C and D correspond to receptor L-selectin (Lsel). The ligands are indicated above the figures. The symbols are experimental results and the lines are analytical curves from Eq. 2, with parameters given in Table 1. The sources for the data are (A and B), ref. 10; (C and D), ref. 20. For A and B, the symbol shapes denote three alternate ways of estimating experimental τ(F). Squares: average of the lifetimes; triangles: SD of the lifetimes; circles: −1/slope in the logarithmic plot of the number of events with lifetime t or more versus t. Up to sampling errors, these estimates are equivalent for systems with exponentially distributed bond lifetimes.