The Influence Of Antifreeze Proteins On Ice-water Interface Ststem From Molecular Dynamics Simulations

Antifreeze proteins(AFPs),a kind of special proteins,exist in some organisms that survive in cold environment,which can protect cell from freeze.These proteins have a common characteristic that can lower growth point of ice crystals without changing their melting point in a noncolligative manner,and can limit the growth and recrystalslization of ice crystals.The phenomenon that affects the growth behavior of ice crystals is defined as thermal hysteresis(TH).Antifreeze proteins have broad application prospects in the field of biology research due to its unique antifreeze properties.In this article,the effect that basal,prism and secondary prism ice-water interface systems were adsorbed AFPs from Tenebrio molitor(TmAFP)and winter flounder(wfAFP),which are analyzed by using molecular dynamics simulation method.The simulation results show that the wfAFP and TmAFP can induce the solid phase ice crystals in the ice-water system to convert into liquid water at temperatures below the melting point.In addition,the non-antifreeze protein(2N3D)is similar to the structure and molecular weight of TmAFP,so they were selected for comparison.It was found that TmAFP is easily adsorbed on the basal surface of ice crystals by analyzing the number of hydrogen bonds formed between AFPs and the ice-water interface.However,the 2N3 D structure is extremely unstable and it is presumed that it may lose its activity under low temperature conditions.This work provides a new way to understand the mechanism of thermal hysteresis activity of AFPs at the molecular level.