Measuring the Electrostatic Drag of Dyaction

Dynactin, an activator of dynein, connects intracellular cargo to dynein motors.  Linear stochastic models are developed to describe the interaction of intracellular cargo, an anchor, and a functionalized motor.  These models use known parameters and available data for dynactin to produce an estimate of electrostatic drag.  Using available data for kinesin, we deduce that  dynactin reduces the velocity of kinesin by about 17%.  When values for dynein are used, a contradiction in estimate occurs for electrostatic drag, suggesting that dynactin affects dynein in a more complicated way.