Extended Data Fig. 1: FRET spectroscopy measurements reveal that the catch bond construct assembles in the weak state 1.
a: Catch bond candidates with varying latch sequence length NLatch and barrier sequence length NBarrier (sequences: CB-CS and CB-HS) were hybridized to Alexa Fluoro labeled DNA oligos (A488-spacer and A565-spacer). The distance between the FRET-dyes is longer in strong state 2, compared to weak state 1. This results in a lower FRET efficiency E, allowing us to distinguish the two states. b: A comparison between experimentally obtained FRET efficiencies (triangles, in duplo) and predicted FRET efficiencies using oxDNA simulations in the weak and strong states (circles) reveals that weak state 1 is the preferred state for each value of Nlatch, including the main catch bond design (NLatch = 7). c: A similar comparison for FRET measurements at varying NBarrier reveals that a minimum of 5 barrier nt is necessary to ensure that weak state 1 is preferred over state 2. The main catch bond design has NBarrier = 6. Experimental details are provided in SI section FRET experiments on the de novo catch bond.
