Fluctuation theorem for a single enzym or molecular motor
Abstract
Cyclically operating enzyms and molecular motors are shown to be restricted nonlinearly by a fluctuation theorem that basically relates the number of backward steps to that of forward steps. Only if the rates obey a quasiequilibrium form in terms of chemical potentials and mechanical load, this fluctuation theorem becomes the usual one for entropy fluctuations. Boundary terms can be subsumed under an entropy change if one defines a trajectorydependent entropy of the enzym or motor. Explicit expressions are derived for a threestate motor with and without an intermediate state and an enzym with MichaelisMenten kinetics.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 April 2005
 DOI:
 10.1209/epl/i2005100039
 Bibcode:
 2005EL.....70...36S