Engineering tunable catch bonds with DNA.

Unlike most adhesive bonds, biological catch bonds strengthen with increased tension. This characteristic is essential to specific receptor-ligand interactions, underpinning biological adhesion dynamics, cell communication, and mechanosensing. While artificial catch bonds have been conceived, the tunability of their catch behaviour is limited. Here, we present the fish-hook, a rationally designed DNA catch bond that can be finely adjusted to a wide range of catch behaviours. We develop models to design these DNA structures and experimentally validate different catch behaviours by single-molecule force spectroscopy. The fish-hook architecture supports a vast sequence-dependent behaviour space, making it a valuable tool for reprogramming biological interactions and engineering force-strengthening materials.