Hofmeister序列阴离子对蛋白纤维化的影响

发布时间：2018-04-11 19:14

本文选题：蛋白纤维化 + Hofmeister序列　；参考：《河北大学》2017年硕士论文

【摘要】：自19世纪80年代末,捷克科学家Hofmeister发现了一个与蛋白变性有关的序列,即Hofmeister序列,之后与之相关的研究就从未中断过。近年来,更是有许多生物学家和化学家将对Hofmeister序列研究的着眼点转移到其对蛋白聚集的影响上。本文主要通过ThT荧光光谱法和原子力显微镜这两种实验手段,系统地研究并分析了在不同浓度、pH条件下Hofmeister序列阴离子对溶菌酶蛋白纤维化聚集过程以及纤维化聚集体最终形貌的影响。通过筛选与比较,选择Hofmeister阴离子序列中具有代表性的六种阴离子进行研究,选择溶菌酶作为本研究的模型蛋白。通过密集采集在不同条件下Hofmeister序列阴离子加入到溶菌酶体系中的ThT荧光值获得纤维化动力学曲线,利用公式拟合得到动力学参数并进行深入分析在不同条件下加入Hofmeister序列阴离子对溶菌酶蛋白纤维化动力学参数的影响。在溶菌酶纤维化结束后,使用原子力显微镜对Hofmeister序列阴离子影响下的溶菌酶纤维化聚集体的最终形貌进行微观的呈现,对比不同Hofmeister序列阴离子对纤维化形貌的差异影响。通过ThT荧光动力学研究发现:(1)Hofmeister序列中六种阴离子在促进溶菌酶蛋白纤维化的影响上并不与其在序列中的顺序一致,而是呈现一种与Hofmeister序列无关的顺序;(2)在不同浓度条件下,同一Hofmeister序列阴离子对蛋白纤维化的影响行为类似,不同Hofmeister阴离子对蛋白纤维化的影响与(1)中所述一致,呈现与Hofmeister序列无关的顺序;(3)在不同pH条件下,Hofmeister序列阴离子对溶菌酶蛋白纤维化的影响的差异集中于延迟区部分,当pH值增大时,Hofmeister序列阴离子加入到溶菌酶体系中后,动力学参数显示延迟区缩短,但其它规律和前述两种条件下的观察一致。在观察原子力显微镜下所呈现的溶菌酶纤维化聚集体的形貌发现:(1)不同的Hofmeister序列阴离子对溶菌酶蛋白纤维化的最终形貌影响存在差异;(2)不同浓度条件下,同一阴离子加入到溶菌酶中,其蛋白纤维化的最终形貌无明显差异;(3)Hofmeister序列阴离子对溶菌酶蛋白纤维化聚集体的最终形貌影响与pH无关,而是与加入的阴离子有关。
[Abstract]:Since the end of the 1880s, Czech scientist Hofmeister has discovered a sequence related to protein denaturation, the Hofmeister sequence, which has not been interrupted since then.In recent years, many biologists and chemists have shifted their focus on Hofmeister sequences to their effects on protein aggregation.In this paper, ThT fluorescence spectroscopy and atomic force microscope are two kinds of experimental methods.The effects of Hofmeister sequence anions on the aggregation process of lysozyme protein and the final morphology of fibrosis aggregates were systematically studied and analyzed at different pH concentrations.By screening and comparing, six kinds of anions of Hofmeister anion sequence were selected to study, and lysozyme was selected as the model protein in this study.The kinetic curve of fibrosis was obtained by collecting the fluorescence values of Hofmeister sequence anions added to lysozyme system under different conditions.The kinetic parameters of lysozyme protein were obtained by formula fitting and the effect of adding Hofmeister sequence anions on the kinetic parameters of lysozyme protein fibrosis was analyzed in depth.After lysozyme fibrosis was finished, the final morphology of lysozyme fibrosis aggregates under the influence of Hofmeister sequence anions was presented by atomic force microscope (AFM), and the effects of different Hofmeister sequence anions on the morphology of the fibrotic aggregates were compared.The fluorescence kinetics of ThT showed that the effect of six anions on promoting lysozyme protein fibrosis was not the same as that in the ThT sequence, but showed a sequence independent of Hofmeister sequence.The effect of anions of the same Hofmeister sequence on protein fibrosis was similar to that of different Hofmeister anions.The difference of the effect of Hofmeister sequence anions on lysozyme protein fibrosis under different pH conditions was concentrated in the delayed region. When pH value increased, the Hofmeister sequence anions were added to the lysozyme system.The kinetic parameters show that the delay region is shortened, but the other laws are consistent with the observation under the above two conditions.After observing the morphology of lysozyme fibrosis aggregates under atomic force microscope, it was found that the effects of different Hofmeister sequence anions on the final morphology of lysozyme protein fibrosis were different under different concentrations.When the same anion was added into lysozyme, there was no significant difference in the final morphology of the protein fibrosis. The effect of the anion of Hofmeister sequence on the final morphology of lysozyme protein fibrosis aggregates was not related to pH, but to the added anions.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O629

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