Force modulating dynamic disorder: a physical model of catch-slip bond transitions in receptor-ligand forced dissociation experiments.
Recent experiments found that some adhesive receptor-ligand complexes have counterintuitive catch-slip transition behaviors: the mean lifetimes of these complexes first increase (catch) with initial application of a small external force, and then decrease (slip) when the force is beyond some threshold. In this work we suggest that the forced dissociation of these complexes might be a typical rate process with dynamic disorder. The one-dimensional force modulating Agmon-Hopfield model is used to describe the transitions in the single-bond P-selectin glycoprotein ligand 1-P-selectin forced dissociation experiments, which were respectively performed in the constant force [Marshall, Nature (Landon) 423, 190 (2003)] and the ramping force [Evans, Proc. Natl. Acad. Sci. U.S.A 98, 11281 (2004)] modes. We find that, an external force can not only accelerate the bond dissociation, but also modulate the complex from the lower-energy barrier to the higher one; the catch-slip bond transition can arise from a particular energy barrier shape. The agreement between our calculation and the experimental data is satisfactory.
Liu
Fei
F
Center for Advanced Study, Tsinghua University, Beijing, 100084, China. liufei@tsinghua.edu.cn
Ou-Yang
Zhong-can
ZC
D001665:Binding Sites; D003198:Computer Simulation; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000648:ultrastructure*; D008846:Micromanipulation / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D019007:P-Selectin / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D011487:Protein Conformation; D013314:Stress, Mechanical
D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein