3 research outputs found
Molecular Spiders in One Dimension
Molecular spiders are synthetic bio-molecular systems which have "legs" made
of short single-stranded segments of DNA. Spiders move on a surface covered
with single-stranded DNA segments complementary to legs. Different mappings are
established between various models of spiders and simple exclusion processes.
For spiders with simple gait and varying number of legs we compute the
diffusion coefficient; when the hopping is biased we also compute their
velocity.Comment: 14 pages, 2 figure
Fluctuations in Polymer Translocation
We investigate a model of chaperone-assisted polymer translocation through a
nanopore in a membrane. Translocation is driven by irreversible random
sequential absorption of chaperone proteins that bind to the polymer on one
side of the membrane. The proteins are larger than the pore and hence the
backward motion of the polymer is inhibited. This mechanism rectifies Brownian
fluctuations and results in an effective force that drags the polymer in a
preferred direction. The translocated polymer undergoes an effective biased
random walk and we compute the corresponding diffusion constant. Our methods
allow us to determine the large deviation function which, in addition to
velocity and diffusion constant, contains the entire statistics of the
translocated length.Comment: 20 pages, 6 figure