几种抗炎抗菌药物和污染物对蛋白质构象变化研究

发布时间：2018-05-23 22:05

本文选题：咪唑类衍生物 + 全氟化合物　；参考：《河南师范大学》2017年硕士论文

【摘要】：一直以来,抗炎抗菌药物药理性和污染物的毒理性研究受到国内外科学研究者的广泛关注,这些物质可以通过饮食、呼吸以及皮肤接触等方式进入体内,与蛋白质等生物大分子进行直接或者间接的作用,从而影响蛋白质的功能及性质,对人体带来危害,所以其活性成分与蛋白质的作用机制相关课题是现代医学、化学及生物学的研究热点。蛋白质是承载着生命活动各项功能,对生命活动有主导性的作用,它能够和多种外源性药物及污染物进行可逆性结合,因而研究此类小分子对蛋白质构象变化的影响是化学领域中备受关注的重要课题之一。近年来,荧光分析法因其在化学检测、生物样品分析等方面的重要应用价值而引起越来越多化学研究工作者的关注。目前,研究人员已经做了诸多关于小分子对蛋白质构象变化影响的研究,但是更为深入的解释其作用机制方面尚不完善。因此,对小分子与蛋白质的结合机制和作用机理的深入研究仍是一项有意义的工作。针对上述调研,本论文主要介绍的内容包括:1、设计并合成有代表性的三种咪唑类衍生物1-(4-溴苯基)-2,4,5-三苯基-1H-咪唑(BPTI),1-(4-溴苯基)-2-(4-氟苯基)-4,5-二苯基-1H-咪唑(BFDI)和1-(4-溴苯基)-4,5-二苯基-2-(噻吩-2-基)吡啶-2-基)-1H-咪唑(BDTI)。通过光谱法和分子对接研究三种咪唑衍生物与人血清白蛋白的作用机制,考察相互作用的结构特征;通过热力学数据计算焓变和熵变等数值进而分析作用力类型;利用非辐射能量转移方法计算结合距离,最后通过红外光谱和圆二色谱等证实BPTI/BFDI/BDTI对人血清蛋白构象的影响。2、利用荧光光谱法、紫外可见吸收光谱法、红外光谱法以及分子模拟研究了抗菌剂的主要成分三氯生(TCS)和三氯卡班(TCC)与胃蛋白酶的相互作用,拟合计算不同温度下TCS/TCC与胃蛋白酶相互作用的结合常数及位点数,定量分析其对胃蛋白酶二级结构的影响,并通过热力学参数确定TCS/TCC与胃蛋白酶之间的作用力类型,最后利用分子模拟法确定TCS/TCC与胃蛋白酶的结合位置。3、通过光谱法和分子对接方法研究全氟辛酸(PFOA)和全氟壬酸(PFNA)与胃蛋白酶的结合模式,比较它们与胃蛋白酶的结合能力差异;同时,利用时间分辨荧光等方法对PFOA和PFNA与胃蛋白酶猝灭机制加以印证,并通过热力学参数分析其相互作用过程中的主要作用力类型。除此之外,还通过UV-vis、FT-IR、三维荧光解释二者对胃蛋白酶的构象影响,最后通过圆二色谱以及分子对接进一步证实实验结果。
[Abstract]:For a long time, the study of anti-inflammatory and antimicrobial agents and toxicology of pollutants has received extensive attention from scientific researchers at home and abroad. These substances can enter the body through diet, breathing and skin contact. Biological macromolecules such as proteins act directly or indirectly, thus affecting the functions and properties of proteins and harming the human body. Therefore, modern medicine is the subject related to its active components and the mechanism of action of proteins. Research focus in chemistry and biology. Protein is the carrier of various functions of life activities, has the leading role in life activities, it can be combined with a variety of exogenous drugs and pollutants for reversible binding, Therefore, the study of the effect of these small molecules on the conformation change of proteins is one of the most important topics in the field of chemistry. In recent years, fluorescence analysis has attracted more and more attention of chemical researchers because of its important application value in chemical detection and biological sample analysis. At present, researchers have done a lot of research on the effect of small molecules on protein conformation, but it is not perfect to explain the mechanism of protein conformation. Therefore, it is still a meaningful work to study the binding mechanism and action mechanism of small molecules and proteins. In response to the above research, The main contents of this thesis include the design and synthesis of three typical derivatives of imidazole (1: 1, 1-4-bromophenyl) and 1-4-bromophenyl-4-4-bromophenyl-4-diphenyl-4-diphenyl-1H-imidazolium BFDI) and 1-4-bromophenyl-4-4-diphenyl-5-diphenyl-2-(phenothiophenyl)-5-diphenyl-2-(Phenothiophenyl)-5-diphenyl-2-(phenothiophenyl) Pyridine-2-pyridyl-1H-imidazolium (BDTI). The interaction mechanism of three imidazole derivatives with human serum albumin was studied by means of spectroscopic method and molecular docking, and the structural characteristics of the interaction were investigated, the enthalpy change and entropy change were calculated by thermodynamic data, and the types of force were analyzed. The binding distance was calculated by non-radiative energy transfer method. Finally, the influence of BPTI/BFDI/BDTI on the conformation of human serum protein was confirmed by infrared spectroscopy and circular dichroism. The interaction between TCS/TCC and pepsin was studied by infrared spectroscopy and molecular simulation. The binding constants and sites of the interaction between TCS/TCC and pepsin at different temperatures were calculated. The effect of pepsin on the secondary structure of pepsin was quantitatively analyzed, and the type of interaction between TCS/TCC and pepsin was determined by thermodynamic parameters. Finally, the binding sites of TCS/TCC and pepsin were determined by molecular simulation method. The binding modes of PFOAA and PFNA with pepsin were studied by means of spectral method and molecular docking method, and their binding ability with pepsin was compared. At the same time, the quenching mechanism of PFOA and PFNA with pepsin was verified by time-resolved fluorescence method, and the main interaction force types in the process of interaction were analyzed by thermodynamic parameters. In addition, the conformation of pepsin was explained by UV-vis-FT-IR and three-dimensional fluorescence. The experimental results were further confirmed by circular dichroism and molecular docking.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R96;O657.3

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