A theoretical study on the hydration of the model compound of collagen, poly(Gly-Pro-Pro), has been carried out using empirical potential energy functions.
The optimum locations and binding energies of water molecules bound to the model compound have been determined by minimizing the interaction energy. The results have shown that three water molecules per tripeptide are bound to the model compound, two of them making a linkage between different chains through the hydrogen bond, with the binding energies of -15.7, -11.1 and -8.9 kcal/mole.
The stabilization energy due to the presence of water in the first hydration shell has been evaluated by comparing the internal interaction energies between the different groups of the model compound in its non-hydrated and hydrated states where the hydrated molecule is considered as a supermolecule.
The stabilization energy due to the hydration is 43 kcal/mole showing appreciable stabilization on hydration.
The different energy components contributing to the overall stabilization are determined and discussed.
The results suggest that water molecules perform a very important role in the stabilization of the triple-stranded helix structure of collagen through the additional interchain hydrogen bonds.
