Fig.5.

(a) The structure of the human serum retinol binding protein (PDB ID 1rbp) is shown as cartoon and the retinol is shown as ball and stick. (b) The number of water molecules inside the binding cavity versus simulation time. (c) The surface representation of the binding cavity consisting of protein atoms within 6Å of ligand. white: hydrophobic, green: hydrophilic, blue: positive, and red: negative. (d) Water density in the binding cavity of the holo-RBP (PDB ID 1rbp). The green spheres indicate water density greater than 1/2 bulk density. (e) Water density in the binding cavity of the unliganded RBP (PDB ID 1brq). The green spheres indicate regions where the water density is that of half bulk and higher.