Molecular Dynamics Simulation Of Protein Adsorption On Crystal Interfaces

The phenomena of protein's adsorption was found for a long time. It had been widely used in biomedical materials and biomedical engineering. Molecular simulation is a newly developed technology which provides quite an effective academic method for study natural phenomena on microcosmic level. Molecular dynamic (MD) simulation can not only be used to study the static properties of a system, but also the dynamic processes. It provided an important theoretic tool for the research of protein's structure. We can study the dynamic processes of protein's adsorption and the mechanism in protein's adsorption on microcosmic level by using molecular dynamics simulation.In NVT condition, TIP3P water model and CHARMM22 force field were used for the molecular dynamic simulation of poly-lysine's adsorption onto different crystal interfaces. The interfaces are diamond, gold, copper, CuCl and magnesia. It suggests that changes were found in the conformation of protein's main chain during the processes of protein's adsorption onto crystal interfaces. The contents ofα-helix structure in protein are decreased in vary extent. Changes of protein's structure have biggish difference during protein was adsorbed onto different crystal interfaces. This suggests the properties of interfaces have significant effects in protein's adsorption processes. The conformation of poly-lysine undergoes the biggest changes when it adsorbed onto diamond, most dihedral angles exceed the range ofα-helix structure; Conformation changes much when poly-lysine is adsorbed onto gold, the contents ofα-helix structure is also largely decreased; Poly-lysine undergoes certain conformation changes and a decrease of the contents ofα-helix structure in a certain extent was found when it is adsorbed onto copper and CuCl; Yet conformation changes are little , and its structure has little difference withα-helix structure when poly-lysine is adsorbed onto magnesia. The research results provided academic basis for studying the mechanism in protein's adsorption, and have important directive significance of protein's adsorption in practical applications.