Vectorial Loading of Processive Motor Proteins: Implementing a Landscape Picture

Abstract

Individual processive molecular motors, of which conventional kinesin is the most studied quantitatively, move along polar molecular tracks and, by exerting a force $\mathbf{F}=(F_x,F_y,F_z)$ on a tether, drag cellular cargoes, {\em in vivo}, or spherical beads, {\em in vitro}, taking up to hundreds of nanometer-scale steps. From observations of velocities and the dispersion of displacements with time, under measured forces and controlled fuel supply (typically ATP), one may hope to obtain insight into the molecular motions undergone in the individual steps. In the simplest situation, the load force $\mathbf{F}$ may be regarded as a scalar resisting force, $F_x<0$, acting parallel to the track: however, experiments, originally by Gittes {\em et al.} (1996), have imposed perpendicular (or vertical) loads, $F_z>0$, while more recently Block and coworkers (2002, 2003) and Carter and Cross (2005) have studied {\em assisting} (or reverse) loads, $F_x>0$, and also sideways (or transverse) loads $F_y\ne 0$.

References in corpus (1)

• A Simple Kinetic Model Describes the Processivity of Myosin-V

Cited by in corpus (4)

• Stochastic mechano-chemical kinetics of molecular motors: a multidisciplinary enterprise from a physicist's perspective
• Effective rates from thermodynamically consistent coarse-graining of models for molecular motors with probe particles
• Back-stepping, hidden substeps, and conditional dwell times in molecular motors
• A Kinetic Model Describing the Processivity of Myosin-V