Abstract:
Myosin and kinesin are biomolecular motors
found in living cells. By propelling their associated
cytoskeletal filaments, these biomolecular motors facilitate
force generation and material transport in the cells. When
extracted, the biomolecular motors are promising
candidates for in vitro applications such as biosensor
devices, on account of their high operating efficiency and
nanoscale size. However, during integration into these
devices, some of the motors become defective due to
unfavorable adhesion to the substrate surface. These
defective motors inhibit the motility of the cytoskeletal
filaments which make up the molecular shuttles used in the
devices. Difficulties in controlling the fraction of active and
defective motors in experiments discourage systematic
studies concerning the resilience of the molecular shuttle
motility against the impedance of defective motors. Here,
we used mathematical modelling to systematically examine
the resilience of the propulsion by these molecular shuttles
against the impedance of the defective motors. The model
showed that the fraction of active motors on the substrate
is the essential factor determining the resilience of the
molecular shuttle motility. Approximately 40% of active
kinesin or 80% of active myosin motors are required to
constitute continuous gliding of molecular shuttles in their
respective substrates. The simplicity of the mathematical
model in describing motility behavior offers utility in
elucidating the mechanisms of the motility resilience of
molecular shuttles.