The lawnmower: an artificial protein-based burnt-bridge molecular motor

Molecular motors are protein-based machines essential for directional transport of cellular components. Inspired by biology, we have synthesized and characterized a protein-based microscale motor we dub the lawnmower. It is comprised of a spherical hub decorated with trypsin enzymes, and its motion is directed by cleavage of a peptide lawn, which promotes motion towards fresh substrate. Thus, it is designed to act as a burnt-bridge ratchet. We find the lawnmower is capable of superdiffusive motion, and can attain average speeds of up to 80 nm/s. By contrast, lawnmowers exhibit exhibit purely diffusive motion on lawns lacking the peptide substrate. We believe the lawnmower is the first example of an autonomous protein-based synthetic motor purpose-built using nonmotor protein components.