Fig. 1: Conceptual design of a de novo DNA catch bond.
a, Schematic of a fingertrap toy that tightens under tension, forming a stronger interaction. b, Conceptual energy landscape of a two-state, two-pathway catch bond. The activation barriers of transitions are indicated as Ex. At rest, catch bonds dissociate quickly from weak state 1. Tension 'tilts' the energy landscape, trapping the catch bond in strong state 2, which dissociates more slowly. c, Mechanism of the de novo DNA catch bond. Weak state 1 dissociates quickly, via breaking of the crosslink. Tension opens the DNA hairpin in the hairpin strand, forming an intermediate state. When the latch closes, the catch bond transitions to strong state 2, from which dissociation is slower. d, oxDNA simulation snapshots of a catch bond switching from weak state 1 to strong state 2 under tension.
