Models of Antifreeze Proteins Bound to Ice by Tandem Repeat Motif

Antifreeze protein (AFP) can help organisms survive from freezing condition by thermal hysteresis activity to control ice growth and by recrystallization inhibition activity to inhibit recrystallization of ice granules, respectively. By bioinformatics methods especially protein docking, the newly developed models of surface complementarity were used to obtain the molecular models of AFPs and hence to interpret the binding mechanism between AFP and ice. The molecular models of relatively perfect surface complementarity were obtained basing on the three-dimensional structures of AFPs, and among the forces of models of surface complementarity, van der waals force and hydrophobic interaction is the key role. The docking result showed that the tandem repeat motif of each AFP can form the basic framework to support the firm binding between the ice binding sites of AFP and ice surfaces, providing useful insights to understand the molecular mechanism of the binding between AFP and ice.