摘要
从理论上研究毒剂分子结构和发展生化毒剂检测技术对于突发危害性公共卫生事件的应急处置具有重要意义。采用分子动力学傅里叶变换计算方法对葡萄球菌肠毒素蛋白建立大分子体系振动模型并研究了温度对其稳定性和振动频率的影响。结果表明:葡萄球菌毒素平均能量与温度成正比,即温度越高,系统的能量越高;299 K时,其蛋白质回旋半径(R_(g))发生明显变化,说明此时蛋白质处于一个展开不稳定状态,温度对蛋白质结构稳定性有明显影响。计算表明温度对其高频振动光谱影响更大:蛋白中N-H和O-H的拉伸振动的红外强度在299 K最高(5683 u),274 K时最低(1818 u);温度对肽键中C=N键的振动强度基本没有影响,但对振动频率影响很大,当温度为254 K和314 K时,C=N键的振动频率在1593 cm^(-1)处,当温度为264,274,299 K时,C=N键的振动频率发生明显红移(约为10 cm^(-1))。对比实测光谱验证了该计算模型的准确性,表明可以利用其光谱特征信号来实现对该类物质的分子识别和精确预警。
The theoratical study on the molecular structure of toxic agents and the development of the detection technology of biochemical toxic agents are of great significance for the emergency response to the sudden hazardous public health incidents.The molecular dynamics and Fourier transform calculation methods were used to establish a vibration model of macromolecular system for staphylococcal enterotoxin protein,and the effects of temperature on its stability and vibration frequency were studied.The results show that the average energy of staphylococcal toxins is proportional to temperature,i.e.,the higher the temperature,the higher the energy of the system.At 299 K,the gyration radius R_(g) of the protein changes significantly,indicating that the protein is in an unfolding and unstable state at this time,and the temperature has an obvious effect on the stability of the protein structure.Calculations show that temperature has a greater impact on the high-frequency vibration spectrum.Specifically,the infrared intensities of the N H and O H tensile vibrations in the protein are the highest at 299 K(5683 u),and the lowest at 274 K(1818 u).Temperature has basically no effect on the vibration intensity of the C=N bond in the peptide bond,but it has a great impact on the vibration frequency of the C=N bond.When the temperature is 254 K and 314 K,the vibration frequency of the C=N bond is 1593 cm^(-1).When the temperature is 264 K,274 K,and 299 K,the vibration frequency of the C=N bond has a significant red shift(approximately 10 cm^(-1)).The accuracy of the calculation model is verified by comparing the measured spectra,indicating that the molecular identification and precise early warning of such substances can be realized by using their spectral characteristic signals.
作者
刘永刚
杨云帆
唐妍
徐建洁
刘冰
LIU Yonggang;YANG Yunfan;TANG Yan;XU Jianjie;LIU Bing(Analysis and Testing Center,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;State Key Laboratory of NBC Protection for Civilian,Beijing 102205,China)
出处
《西南科技大学学报》
CAS
2022年第1期80-86,共7页
Journal of Southwest University of Science and Technology
基金
国家自然科学基金项目(11872058)。
关键词
葡萄球菌肠毒素蛋白
红外光谱
分子动力学
Staphylococcal enterotoxin protein
Infrared spectroscopy
Molecular dynamics
