Molecular Dynamics Study of the Interactions of Ice Inhibitors on the Ice {001} Surface

The interactions of antifreeze protein (AFP) type I, antifreeze glycoproteins, polyvinyl pyrrolidone (PVP), and various amino acids with ice are investigated using Cerius2, a molecular modelling tool. Binding energies of these additives to a major ice crystal face {001} are computed. Binding energy comparison of threonine molecules (by themselves) and as threonine residues within AFP type I demonstrate their role in improving AFP's binding ability to the ice crystal face. The shifts in onset points of ice crystallization with AFP type I, PVP, and amino acids are measured using differential scanning calorimetry. These values when correlated with their respective binding energies reveal a direct proportionality and demonstrate AFP's effectiveness in inhibiting growth and nucleation of ice, over amino acids.