  Using Langevin dynamics simulations, we investigate the dynamics of
chaperone-assisted translocation of a flexible polymer through a nanopore. We
find that increasing the binding energy $\epsilon$ between the chaperone and
the chain and the chaperone concentration $N_c$ can greatly improve the
translocation probability. Particularly, with increasing the chaperone
concentration a maximum translocation probability is observed for weak binding.
For a fixed chaperone concentration, the histogram of translocation time $\tau$
has a transition from long-tailed distribution to Gaussian distribution with
increasing $\epsilon$. $\tau$ rapidly decreases and then almost saturates with
increasing binding energy for short chain, however, it has a minimum for longer
chains at lower chaperone concentration. We also show that $\tau$ has a minimum
as a function of the chaperone concentration. For different $\epsilon$, a
nonuniversal dependence of $\tau$ on the chain length $N$ is also observed.
These results can be interpreted by characteristic entropic effects for
flexible polymers induced by either crowding effect from high chaperone
concentration or the intersegmental binding for the high binding energy.
