Catch bonds: physical models, structural bases, biological function and rheological relevance

Force can shorten the lifetimes of macromolecular complexes (e.g., receptor-ligand bonds) by accelerating their dissociation. Perhaps paradoxical at first glance, bond lifetimes can also be prolonged by force. This counterintuitive behavior was named catch bonds, which is in contrast to the ordinary slip bonds that describe the intuitive behavior of lifetimes being shortened by force. Fifteen years after their theoretical proposal, catch bonds have finally been observed. In this article we review recently published data that have demonstrated catch bonds in the selectin system and suggested catch bonds in other systems, the theoretical models for their explanations, possible structural bases, their relation to flow-enhanced adhesion, and the potential biorheological relevance.