Molecular Dynamics Simulation For The Adsorption And Combination Of Antifreeze Protein And Ice Crystal On Different Crystal Plances

Antifreeze proteins(AFPs is a kind of special proteins exist in many organisms that living in cold environment,which can prevent cells from being destroyed by freezing.These proteins can inhibit growth and recrystallization of ice crystal in a non-colligative manner.The antifreeze protein has the characteristics of inhibiting the growth of ice crystals,so it has wide application prospects in many fields such as low-temperature storage and food preservation.In this paper,using the method of full-atom molecular dynamics simulation(MD),from the molecular level,both the structural stability of the tenebrio molitor antifreeze protein(TmAFP)molecules,macrozoarces americanus antifreeze protein(Za AFP)molecules and a kind of non-protein bacillus protein molecules that structure are very similar to TmAFP molecules,have been analyzed in low-temperature water environment.The simulation results show that TmAFP molecules and Za AFP molecules are structurally stable in low-temperature water environments,while the non-antifreeze protein bacillus protein molecules are unstable.We select TmAFP molecules with stable structures in low-temperature water environment as the research object.The interaction between TmAFP molecules and basal plane,prism plane and secondary plane of ice crystal also have been analyzed at the molecular level respectively.The simulation results show that TmAFP molecules can inhibit the growth of ice crystals to a certain extent when they are adsorbed on the basal plane or prism plane or secondary prism plane of ice crystals.In the simulation process,the interaction energy of TmAFP molecules and ice crystal is the largest when they are adsorbed on prism plane of ice crystals,and the interaction energy fluctuates little over time.Electrostatic interaction plays a major role in the adsorption and binding process of TmAFP molecules and ice crystal planes.The relative position of TmAFP molecules and crystal plane of ice crystal are the most stable in the prism plane ice-water system.And the structure of TmAFP molecules are the most stable in the prism plane ice-water system.The research results show that TmAFP molecules can select different types of ice crystal faces for adsorption and binding.Due to the diversity of binding to ice crystals TmAFP molecules can affect the growth behavior of ice crystals more effectively.A further understanding of this polycrystalline surface selecting adsorption can provide new ways for understanding the adsorption-inhibition mechanism of antifreeze protein.And it can also give a theoretical reference for the experimental search for protein molecules that with antifreeze properties.