论文部分内容阅读
天然的低温脂肪酶往往结构热稳定性比较差,制约了其长时间有效地发挥催化作用及保存.该研究以来源于白色念珠菌(Candida albicans)的低温脂肪酶Lipase 5为对象,运用相关分子动力学方法进行研究,提出了提高其热稳定性的理论策略.首先运用同源建模方法构建目标蛋白的三维结构模型;然后通过18ns分子动力学模拟,锚定目标蛋白不稳定区域中柔性氨基酸(甘氨酸)的位置,并将这些柔性氨基酸位点突变为刚性氨基酸(脯氨酸);最后利用分子动力学模拟来验证这些突变对蛋白质热稳定性的影响.结果发现,将Lipase 5三维结构中的第279位甘氨酸突变为脯氨酸后,使得蛋白质热稳定性增强.这为类似低温脂肪酶的热稳定性改造的实验设计提供了理论支持.
Natural low-temperature lipase is often poor in thermal stability, restricting its long-term effective catalytic and preservation.In this study, lipase derived from Candida albicans lipase 5 as a target, the use of related molecules Kinetic method and put forward a theoretical strategy to improve its thermal stability.Firstly, the three-dimensional structural model of target protein was constructed by homology modeling method, and then 18ns molecular dynamics simulation was performed to anchor the flexible amino acids in the unstable region of target protein (Glycine), and these flexible amino acid sites were mutated to rigid amino acids (proline). Finally, molecular dynamics simulations were performed to verify the effect of these mutations on the thermostability of the protein. The results showed that the three-dimensional structure of Lipase 5 Of the 279th glycine to proline increased the thermostability of the protein, which provided theoretical support for the experimental design of thermostability modification like low temperature lipase.