化学修饰胰蛋白酶的溶剂化能计算

SOLVATION ENERGY CALCULATION ON CHEMICALLY MODIFIED TRYPSIN

运用分子模拟技术研究亲水化修饰胰蛋白酶热稳定性提高的机理 .首先从天然胰蛋白酶晶体结构出发 ,运用统一价键力场 (CVFF)对氨基修饰前后酶分子结构进行合理建模 ,再用Ooi模型和Vila模型计算了胰蛋白酶修饰前后溶剂化能的变化 .结果发现 ,酶经化学修饰后溶剂化能呈下降趋势 ,修饰程度越高 ,下降程度越大 .深入分析溶剂化能与酶热稳定性关系 ,发现溶剂化能下降有利于酶热稳定性的提高 ,从理论上验证了文献报道的胰蛋白酶亲水化修饰实验结果 .

In this paper, the molecular simulation technique is used to study the stabilization effect of trypsin caused by hydrophilization modification. First, the tertiary structure of amine modified trypsin are built by the CVFF force field based on the crystal structure of native trypsin. The Ooi model and the Vila model are used to calculate the solvation energy of native and amine modified trypsin based on their tertiary structures. The computational results show that the solvation energy of trypsin decreases obviously after modification, with the higher degree of modification corresponding to the lower value of solvation energy. After analyzing the relationship between the solvation energy and the thermal stability in detail, it is found that the change of solvation energy can qualitatively describe the thermal stability of native and hydrophilization modified trypsin.