SDBS及NaOH诱导蛋白质在云母表面解吸附的原子力显微镜研究

发布时间：2018-12-12 06:33

【摘要】：蛋白质是生物体内重要的组成成分之一,几乎参与所有的生命活动和生命过程。蛋白质几乎可以自发地吸附在任何材料表面上,这种现象很早就已经被人们发现。蛋白质在界面上的吸附是一种普遍现象,也是解决界面科学、生物材料以及生物工程领域中许多问题的关键,对蛋白质在界面上吸附问题的研究有着重要的理论和实际意义。目前对于蛋白质在材料上吸附行为的研究较为成熟,对于其在材料上解吸附行为的研究还处于初级阶段。当前对于蛋白质在云母表面解吸附的研究还未见报道,本文旨在探索出蛋白质在云母上解吸附的方法。借助于原子力显微镜(AFM)直观地观察了牛血清白蛋白(BSA)和溶菌酶这两种特征蛋白在云母表面的吸附、解吸附情况。解吸附是以十二烷基苯磺酸钠(SDBS)和氢氧化钠(NaOH)溶液为解吸附剂得以实现的。本论文的主要研究工作如下:1.SDBS诱导蛋白质从云母表面解吸附的AFM研究。以SDBS为解吸附剂,通过SDBS与蛋白质之间的相互作用,实现蛋白质从云母表面的解吸附。AFM表征结果显示,牛血清白蛋白和溶菌酶在云母表面的吸附量随蛋白质溶液浓度的增加而增加;随吸附时间增加而增加;蛋白质的脱附程度随SDBS浓度增加而增大;随脱附时间的增加而增大;中性环境下溶菌酶比BSA更容易吸附在云母表面;溶菌酶比BSA更不容易发生解吸附。2.NaOH诱导蛋白质从云母表面解吸附的AFM研究。蛋白质是氨基酸构成的一种两性电解质,在一定的溶液pH条件下可解离成带负电荷或正电荷的基团。通过改变溶液的pH使蛋白质带负电或负电性增强从而使云母与蛋白质的静电斥力大于二者之间的引力,进而实现蛋白质从云母上的解吸附。AFM表征结果显示,将吸附样品浸入到氢氧化钠溶液中可以使BSA和溶菌酶从云母上解吸附下来;使BSA发生解吸附的pH值与其等电点相差很大,而使溶菌酶发生解吸附的pH值与其等电点基本一致。
[Abstract]:Protein is one of the most important components in organism, which is involved in almost all life activities and processes. Proteins can spontaneously adsorb on almost any material surface, a phenomenon that has long been known. The adsorption of proteins on the interface is a common phenomenon and the key to solve many problems in the field of interface science, biomaterials and bioengineering. It is of great theoretical and practical significance to study the problem of protein adsorption on the interface. At present, the study on the adsorption behavior of protein on the material is more mature, and the study on the desorption behavior of protein on the material is still in the primary stage. At present, the study of protein desorption on mica surface has not been reported. The purpose of this paper is to explore the method of protein desorption on mica surface. The adsorption and desorption of bovine serum albumin (BSA) (BSA) and lysozyme on mica surface were observed intuitively by atomic force microscope (AFM). The desorption was achieved by using sodium dodecylbenzene sulfonate (SDBS) and sodium hydroxide (NaOH) as desorption agents. The main work of this thesis is as follows: AFM study of 1.SDBS induced protein desorption from mica surface. Using SDBS as desorption agent, the desorption of protein from mica surface was realized by the interaction between SDBS and protein. The results of AFM characterization showed that, The adsorption of bovine serum albumin and lysozyme on mica surface increased with the increase of protein concentration. The desorption degree of protein increased with the increase of SDBS concentration, and increased with the increase of desorption time. Lysozyme was more easily adsorbed on the surface of mica than that of BSA in neutral environment. Lysozyme is less easily desorbed than BSA. AFM study of 2.NaOH induced protein desorption from mica surface. Protein is a amphoteric electrolyte composed of amino acids, which can be dissociated into negative or positively charged groups under certain solution pH conditions. By changing the pH of the solution, the protein with negative charge or negative charge is enhanced, so that the electrostatic repulsive force between mica and protein is greater than the gravity between them, and then the desorption of protein from mica is realized. The results of AFM characterization show that the electrostatic repulsive force between mica and protein is greater than that between mica and protein. BSA and lysozyme can be desorbed from mica by soaking the adsorbed sample into sodium hydroxide solution. The pH value of BSA desorbed was significantly different from its isoelectric point, but the pH value of lysozyme desorbed was basically consistent with its isoelectric point.
【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】：O647.3

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