  We study the enzymatic degradation of an elastic fiber under tension using an
an isotropic random-walk model, coupled with binding-unbinding reactions that
weaken the fiber. The fiber is represented by a chain of elastic springs in
series, surrounded by two layers of sites along which enzyme molecules can
diffuse. Through numerical simulations we show that the fiber stiffness
decreases exponentially with two distinct regimes. The time constant associated
with the first regime decreases with increasing applied force, which is in
agreement with published experimental data. In addition, a simple mean field
calculation allows us to partition the time constant into geometrical, chemical
and externally controllable factors, which is corroborated by the simulations.
