Colloquium - Chapin Korosec

Dr. Chapin Korosec

Adjunct Professor
Dept. of Mathematics & Statistics, University of Guelph, Guelph, Canada

Modelling and engineering burnt-bridge ratchet molecular motors

Molecular motors are protein-based machines essential for directional transport of cellular components. Nature has evolved many mechanisms for achieving directed motion on the subcellular level. The burnt-bridge ratchet (BBR) is one mechanism used to achieve superdiffusive molecular motion over long distances through the successive cleavage of surface-bound energy-rich substrate sites. The BBR mechanism is utilized throughout Nature: it can be found in bacteria, plants, insects, humans, as well as non-life forms such as influenza. Inspired by biology, we have synthesized and characterized a protein-based microscale motor we dub the lawnmower [1]. We find the lawnmower demonstrates saltatory motion where superdiffusive runs are interspersed with subdiffusive dynamics, with the system reaching average speeds of 80 nm/s. The lawnmower is the first example of an autonomous protein-based synthetic motor purpose-built using nonmotor protein components. In this talk, I will discuss the lawnmower system and its implementation in microfabricated tracks where we demonstrate it is capable of track-guided motion. I will also discuss our Langevin [2] and Gillespie [3] simulation approaches, where we seek to understand how BBR engineering principles alter particle dynamics. Our work provides insights into the mechanistic origin for the observed dynamics found in both synthetic and natural (e.g. Influenza) systems.

[1] C.S. Korosec et al. (2024). “Motility of an autonomous protein-based artificial motor that operates via a burnt-bridge principle.” Nature Communications, 15(1511).
[2] C.S. Korosec et al. (2021). “Substrate stiffness tunes the dynamics of polyvalent rolling motors.” Soft Matter, 17(6).
[3] C.S. Korosec et al. (2018). “Dimensionality-dependent crossover in motility of polyvalent burnt-bridges ratchets.” Physical Review E, 98(3).