Rotary and linear molecular motors driven by pulses of a chemical fuel

TLDR

Biomolecular motors harness the energy from chemical fuel hydrolysis, such as ATP, to drive motion through information ratchet mechanisms. This work introduces chemically‑driven artificial rotary and linear molecular motors that function via a distinct mechanism. The motors operate by acid‑base oscillations that alternately alter binding‑site affinities and barrier labilities, forming an energy ratchet, and are powered by aliquots of trichloroacetic acid. Acid‑base oscillations induce directional rotation of [2]‑ and [3]‑catenane rotary motors and substrate transport by a linear pump, with a single fuel pulse achieving 360° unidirectional rotation in up to 87 % of crown‑ether‑containing [2]‑catenanes.

Abstract

Many biomolecular motors catalyze the hydrolysis of chemical fuels, such as adenosine triphosphate, and use the energy released to direct motion through information ratchet mechanisms. Here we describe chemically-driven artificial rotary and linear molecular motors that operate through a fundamentally different type of mechanism. The directional rotation of [2]- and [3]catenane rotary molecular motors and the transport of substrates away from equilibrium by a linear molecular pump are induced by acid-base oscillations. The changes simultaneously switch the binding site affinities and the labilities of barriers on the track, creating an energy ratchet. The linear and rotary molecular motors are driven by aliquots of a chemical fuel, trichloroacetic acid. A single fuel pulse generates 360° unidirectional rotation of up to 87% of crown ethers in a [2]catenane rotary motor.