9723271 Madura The overall goals of this work are to advance the understanding of the interactions of antifreeze proteins (AFP) at the ice/water interface by performing explicit and implicit ice/AFP/ water computer simulations, study experimentally ice crystal growth and its modification by AFPs, and the development and testing of synthetic analogs. Due to the great complexity of the molecule-interface interactions in this system the success of this project is only possible through a complementary computational and experimental approach. To achieve the objectives, work will focus on the following tasks: The simulation of two similar AFPs (winter flounder and shorthorn sculpin) Cryogenic microscopy procedures for studying and analyzing antifreeze activity will be explored to probe the interactions between AFPs and ice. Using the simulation data and cryomicroscopy results, antifreeze analogs will be synthesized and tested for noncolligative antifreeze activity. These synthetic analogs will be studied in simulation experiments as well as by splat cooling and nanoliter osmometry. The overall significance of this work will be the development of a comprehensive, unified theory for the mechanism of action for antifreeze proteins. In addition the results from this work will provide a basic understanding how proteins and polypeptides can modify crystal growth. Finally, the results from this study will have an enormous impact on society. Areas of impact include the food industry (food preservation, etc.), agricultural industry: frost sensitive crops (fruits and vegetables) antifreeze fuel additives, and aircraft industry (de-icers). ***