Mechanical model of kinesin moving on microtubule

Kinesins are biomolecules that serve as intercellular motors for carrying cellular cargos along microtubules. Although the mechanism of converting the chemical energy of ATP to mechanical work is not fully understood, the motion of a kinesin on a microtubule has been measured and two different mechanisms, namely the “hand-over-hand” and “inchworm”, has been proposed. The particular shape of kinesin and microtubules suggest a possible mechanism for force generation similar to Brownian ratchet. Using a bead chain connected to two heads that are attracted to a vibrated ratchet plate as a scaled up analog of the kinesinmicrotubule system, we manage to simulate both “handoverhand” and “inchworm” motion [Chou, et. al., Physica A443, 66 (2015)]. In addition, we find that chain, which play the role of the stalk in a kinesin molecule, can also generate force by interacting with the ratchet plate [Chen, et. al. Phys. Rev. E87, 012711 (2013)].