  The coil-globule transition of hetero-polymer chains is studied here. By
means of extensive Molecular Dynamics simulations, we show that the transition
is directly linked to the complexity of the chain, which depends on the number
of chemical species defined in the environment and the location of the binding
sites along the polymer. In addition, when the number of species increases, we
find that the distribution of binding sites plays an important role in
triggering the transition, beyond the standard control parameters of the
polymer model, i.e. binders concentration and binding affinity. Overall, our
results show that by increasing the system complexity new organizational layers
emerge, thus allowing a more structured control on the polymer thermodynamic
state. This can be potentially applied to the study of chromatin architecture,
as such polymer models have been broadly used to understand the molecular
mechanisms of genome folding.
