Spontaneous Oscillations of Collective Molecular Motors (original) (raw)

We present a physical mechanism which can lead to oscillatory motion of molecular motors cooperating in large groups when the system is elastically coupled to its environment. Analytical and numerical calculations reveal a characteristic type of oscillatory behavior with cusplike extrema. Typical oscillation frequencies are determined by the internal time scales of the motors. The physical mechanism we describe generates in a natural way many of the characteristic properties of spontaneous oscillations observed in some muscles and myofibrils. [S0031-9007(97)03323-1] PACS numbers: 87.10. + e, 05.40. + j Motor proteins are highly specialized macromolecules which can consume mechanical energy to induce motion and to generate forces. These molecules are involved in active transport processes, cell locomotion, and muscle contraction . A typical motor molecule specifically attaches to a certain protein filament which serves as a track for its motion. In the presence of fuel, which in the cell is the molecule adenosine triphosphate (ATP), the motor starts moving in a direction defined by the polarity of the track. Experimental methods allow one to measure forces and velocities of individual motors or small groups of motors .