  Unstructured proteins can modulate cellular responses to environmental
conditions by undergoing coil-globule transitions and phase separation.
However, the molecular mechanisms of these phenomena still need to be fully
understood. Here, we use Monte Carlo calculations of a coarse-grained model
incorporating water's effects on the system's free energy. Following previous
studies, we model an unstructured protein as a polymer chain. Because we are
interested in investigating how it responds to thermodynamic changes near a
hydrophobic surface under different conditions, we choose an entirely
hydrophobic sequence to maximize the interaction with the interface. We show
that a slit pore confinement without top-down symmetry enhances the unfolding
and adsorption of the chain in both random coil and globular states. Moreover,
we demonstrate that the hydration water modulates this behavior depending on
the thermodynamic parameters. Our findings provide insights into how
homopolymers, and possibly unstructured proteins, can sense and adjust to
external stimuli such as nanointerfaces or stresses.
