Gold nanocrystal-mediated sliding of doublet DNA origami filaments

TL;DR

This study demonstrates a novel DNA nanotechnology-based system where gold nanocrystals facilitate reversible, stepwise sliding of DNA origami filaments, mimicking biological and macroscopic mechanical movements, advancing nanomachinery design.

Contribution

Introduction of a gold nanocrystal-mediated sliding mechanism for DNA origami filaments, with in situ fluorescence monitoring and theoretical modeling, expanding DNA nanomachinery capabilities.

Findings

Reversible stepwise sliding of DNA origami filaments observed.

Fluorescence spectroscopy confirms coordinated movement.

Sliding persists despite inhibitory DNA sidelocks.

Abstract

Sliding is one of the fundamental mechanical movements in machinery. In macroscopic systems, double-rack pinion machines employ gears to slide two linear tracks along opposite directions. In microscopic systems, kinesin-5 proteins crosslink and slide apart antiparallel microtubules, promoting spindle bipolarity and elongation during mitosis. Here we demonstrate an artificial nanoscopic analog, in which gold nanocrystals can mediate coordinated sliding of two antiparallel DNA origami filaments powered by DNA fuels. Stepwise and reversible sliding along opposite directions is in situ monitored and confirmed using fluorescence spectroscopy. A theoretical model including different energy transfer mechanisms is developed to understand the observed fluorescence dynamics. We further show that such sliding can also take place in the presence of multiple DNA sidelocks that are introduced to inhibit the relative movements. Our work enriches the toolbox of DNA-based nanomachinery, taking one step further toward the vision of molecular nanofactories.