干燥过程中LEA-motif蛋白特征重复片段对POPE膜结构的保护研究

通过分子动力学模拟的方法, 模拟了1-棕榈酰基-2-油酰基磷脂酰乙醇胺(1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine, POPE)生物膜在添加胚胎发育晚期丰富蛋白(Late embryogenesis abundant proteins, LEA蛋白)特征重复片段(LEA-motif)前后两种体系在低温下的干燥过程, 对比分析了干燥过程中两种体系在POPE生物膜结构、 扩散系数、 侧链有序性及分子间氢键数目的变化, 从微观角度揭示了POPE生物膜因干燥失水导致的结构变化以及添加LEA-motif之后LEA-motif与POPE生物膜的相互作用. 结果表明, LEA-motif在脱水干燥过程中能够有效地稳定膜的结构, 从而保护生物材料的生物活性.

Protection of LEA-motif for POPE Membrane During Desiccation†

Late embryogenesis abundant(LEA) protein is a kind of low molecular weight and high hydrophilic protein and the expressions of it are correlated with desiccation tolerance. Combined with their multitudinous biological functions, such as stabilizing membranes and proteins, scavenging free radicals and so on, LEA would be good and potential preotectant for biomaterials. However, the protective mechanism of LEA protein for membrane is not clear and definite, which results in the absence of abrupt development for the actual applications. Therefore, the drying process of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine(POPE) membrane with or without LEA-motif protectant at low temperature was thoroughly researched by molecular dynamics simulation. The results such as the 3D structure of POPE membrane, the lateral diffusion coefficient of POPE lipids, the order parameter of hydrophobic chains and the H-bonding interactions were analysized and compared between the two systems detailedly. The damage of POPE membrane and the bioactive protection of LEA-motif to the POPE membrane during desiccation were revealed from the microscopic view. The results indicate that LEA-motif can stabilize the structure of POPE membrane and then maintain the biological activity of biomaterials.