为了研究点突变(Met108→Leu108)对树胶醛糖结合蛋白(ABP)与配体结合能力的影响,对ABP、ABP结合树胶醛糖复合物及ABP结合半乳糖复合物以及它们各自的突变体分别进行60 ns的分子动力学模拟。模拟结果表明,108号残基突变前后,电子等排体的两个氨基酸残基,使蛋白与配体间的范德华相互作用发生明显变化,同时导致蛋白的内部运动也发生变化,进而影响蛋白与配体的相互作用。进一步分析表明,突变前后的蛋白构象变化都趋向于两个结构域张开,而与配体的结合可减缓张开程度。
In order to understand the effect of the mutant(Met108→Leu108) of the arabinose-binding protein ( ABP) on the interactions between the protein and ligand, a series of 60 ns molecular dynamics simulations for the ABP, ABP bound ARA, ABP bound GAL and their mutants was performed, respectively. The results show that the mutation(Met108→Leu108) in ABP leads to the significant change of the van der Waals interac-tion between residue 108 and ligand, which further causes the changes of the protein's internal motion and in-teractions between the protein and ligand. The varieties in interaction between the protein and ligand make the two globular domains of wild-type and mutation-type of ABP gradually open and the ligand binding can control the open movement of the protein.