Ensemble velocity of non-processive molecular motors with multiple chemical states

  title={Ensemble velocity of non-processive molecular motors with multiple chemical states},
  author={Andrej Vilfan},
  journal={Interface Focus},
  • A. Vilfan
  • Published 27 September 2014
  • Physics
  • Interface Focus
We study the ensemble velocity of non-processive motor proteins, described with multiple chemical states. In particular, we discuss the velocity as a function of ATP concentration. Even a simple model which neglects the strain dependence of transition rates, reverse transition rates and nonlinearities in the elasticity can show interesting functional dependencies, which deviate significantly from the frequently assumed Michaelis–Menten form. We discuss how the order of events in the duty cycle… 

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  • 1999
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It transpires that the large-load performance is determined by the geometrical placement of the intermediate mechanochemical states of the enzymatic cycles relative to the associated transition states, and physical colocalization of biochemically distinct states generally implies large- load velocity saturation.

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The simplest (N = 2)-state model with fixed load-distribution factors and kinetic rate constants concordant with stopped-flow experiments, accounts for the global (V, F, L, [ATP]) interdependence and, further, matches relative acceleration observed under assisting loads.

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Single kinesin molecules studied with a molecular force clamp

The kinesin cycle contains at least one load-dependent transition affecting the rate at which ATP molecules bind and subsequently commit to hydrolysis, and it is likely that at leastOne other load- dependent rate exists, affecting turnover number.

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