Figure 3. Single molecule measurements of the α₄β₁/VCAM-1 complex.

(A) Representative force-distance curves were acquired during cantilever retraction (∼3 µm/s) following a contact time of 100 ms. (Top Trace) Single tethered rupture event. Quantification of tether lifetimes (τ) and extraction forces (f _e) are depicted. (Middle Trace) Single cytoskeleton anchored rupture event. Loading rates (r) were determined from the linear slope of the force-distance curve immediately prior to the rupture, as indicated by the dashed line. Rupture force (f _r) is determined from the peak of the rupture event to zero force (horizontal dash line). (Bottom Trace) Measurements exhibiting multiple ruptures. (B) Work of detachment (mean ± s.e.m.) for single molecule adhesion of a cytoskeleton-anchored and membrane-tethered α₄β₁/VCAM-1 complex.