PDF(Pubmed)
Abstract：
We analyzed the thermal stability of the BstHPr protein through the site-directed point mutation Lys62 replaced by Ala residue using molecular dynamics simulations at five different temperatures: 298, 333, 362, 400, and 450 K, for periods of 1 μs and in triplicate. The results from the mutant thermophilic BstHPrm protein were compared with those of the wild-type thermophilic BstHPr protein and the mesophilic BsHPr protein. Structural and molecular interaction analyses show that proteins lose stability as temperature increases. Mutant and wild-type proteins behave similarly up to 362 K. However, at 400 K the mutant protein shows greater structural instability, losing more buried hydrogen bonds and exposing more of its non-polar residues to the solvent. Therefore, in this study, we confirmed that the salt bridge network of the Glu3-Lys62-Glu36 triad, made up of the Glu3-Lys62 and Glu36-Lys62 ion pairs, provides thermal stability to the thermophilic BstHPr protein.
摘要：
我们使用分子动力学模拟在五个不同温度下分析了BstHPr蛋白的热稳定性：298、333、362、400和450K，通过定点点突变Lys62被Ala残基取代，持续1μs的时间，一式三份。将突变的嗜热BstHPrm蛋白的结果与野生型嗜热BstHPr蛋白和嗜热BsHPr蛋白的结果进行了比较。结构和分子相互作用分析表明，随着温度升高，蛋白质会失去稳定性。突变体和野生型蛋白的行为相似，最高可达362K。然而，在400K时，突变蛋白显示出更大的结构不稳定性，失去更多的隐藏的氢键，并将更多的非极性残基暴露于溶剂。因此,在这项研究中，我们证实了Glu3-Lys62-Glu36三合会的盐桥网络，由Glu3-Lys62和Glu36-Lys62离子对组成，为嗜热BstHPr蛋白提供热稳定性。
