第一类鱼抗冻蛋白与天然气水合物吸附结合过程中局部结构变化研究

Study on the Local Structure Changes of the First Kind of AFP-Ⅰduring the Adsorption and Binding Process of Natural Gas Hydrate

采用分子动力学模拟方法,计算分析第一类鱼抗冻蛋白(AFP-Ⅰ)在与天然气水合物吸附结合过程中局部结构的变化,并通过AFP-Ⅰ氨基酸突变体模拟结果来进一步说明AFP-Ⅰ抑制水合物生长的作用机理。结果表明,在AFP-Ⅰ与水合物结合过程中分子局部结构发生改变,水合物结合位点(Hydrate-binding site,HBS)处部分氨基酸残基的甲基发生迁移以适应水合物的笼状结构并取代甲烷分子与水合物表面结合。此外,氨基酸突变体模拟表明AFP-Ⅰ侧链上的甲基的缺失会减弱抗冻蛋白与水合物的结合能力。研究结果对研发可降解的天然产物类水合物抑制剂具有参考意义。

Molecular dynamics simulation was used to calculate and analyze the local structural changes of the typeⅠantifreeze protein(AFP-Ⅰ)during the adsorption and binding process with natural gas hydrate,and the results of AFP-Ⅰamino acid mutant simulation were used to further illustrate the mechanism of the action of AFP-Ⅰin inhibiting hydrate growth.Our results indicate that AFP-Ⅰundergoes local structural changes during hydrate binding,with the methyl groups of some amino acid residues at the hydrate binding site(HBS)adapting and migrating to the cage-like structure of the hydrate.This allows the amino acid residues to bind to the surface of the hydrate by replacing existing methane molecules.In addition,the amino acid mutant simulations show that deleting the methyl group on the side chain of AFP-Ⅰweakens its ability to bind to the hydrate.The results have significant implications for the development of environmentally friendly,degradable,natural product-based hydrate inhibitors.