表面化学性质调控的纳米金与牛血清蛋白相互作用的研究
发布时间：2018-10-14 16:19
【摘要】：蛋白质是一切生命的物质基础,生物体内的各种化学反应都离不开蛋白质的参与,可以说没有蛋白质就没有生命活动的存在。纳米金具有独特的小尺寸效应、表面效应、光学效应、量子效应以及良好的生物相容性等,在生物、化学、医药、信息科学等领域得到了广泛的应用。近年来,纳米金已经成为科研工作者研究的热点。纳米金作为药物及药物载体进入生物体内,在其表面形成“蛋白晕”,赋予纳米金新的生物识别性,从而改变其生理反应和毒性。因此,研究不同表面化学性质的纳米金与牛血清白蛋白(BSA)的相互作用,对于全面理解“蛋白晕”的形成因素及发展更为安全有效的生物纳米材料具有重要的指导作用。作为国家自然科学基金(No.21303043)资助课题的一部分,本论文以不同表面化学性质的纳米金与BSA作为研究对象,运用紫外-可见吸收光谱(UV-vis)、荧光光谱、圆二色谱(CD)、傅里叶红外光谱(FTIR)、动态光散射(DLS)、透射电镜(TEM)等技术研究不同表面化学性质的纳米金与BSA的相互作用。荧光光谱和UV-vis研究结果揭示了纳米金表面化学性质对其与BSA相互作用机制的影响。其中,半胱氨酸、谷胱甘肽、PEG(2K)及多肽修饰的纳米金与BSA相互作用形成了基态复合物,以静态猝灭为主。而聚合物PEG(5K)、PEG-COOH(5K)修饰的纳米金与BSA相互作用不形成复合物,以动态猝灭为主。借助同步荧光光谱、CD、FTIR等技术,探讨了牛血清蛋白质与不同表面化学性质的纳米金作用前后构象的变化。结果表明,PEG(5K)及多肽修饰的纳米金对BSA构象的影响不大,而半胱氨酸、谷胱甘肽、PEG(2K)、PEG-COOH(5K)、CTAB修饰的纳米金对BSA的二级结构有较大的影响。此外,运用DLS技术考察不同表面化学性质的纳米金表面所形成的“蛋白晕”厚度。我们发现,纳米金的表面化学性质对“蛋白晕”的形成有重要的影响。最后,利用UV-vis吸收光谱研究BSA对不同表面化学性质的纳米金聚集状态的影响。实验结果初步表明,纳米金的表面电荷是影响其聚集状态的主要因素。本研究工作的开展,对进一步理解纳米材料与蛋白质相互作用的本质及纳米粒子的生物学效应具有重要的参考价值。
[Abstract]:Protein is the material basis of all life. All kinds of chemical reactions in organism can not be separated from the participation of protein, so it can be said that there is no life activity without protein. Nanocrystalline gold has been widely used in biology, chemistry, medicine, information science and so on because of its unique small size effect, surface effect, optical effect, quantum effect and good biocompatibility. In recent years, nanocrystalline gold has become a hot research topic for researchers. Nanocrystalline gold, as a drug and drug carrier, forms a "protein halo" on its surface, which endows it with new biologic recognition, which changes its physiological reaction and toxicity. Therefore, the study of the interaction between gold nanoparticles with different surface chemical properties and bovine serum albumin (BSA) (BSA) plays an important role in understanding the formation factors of "protein halo" and developing more safe and effective biomaterials. As a part of the project supported by the National Natural Science Foundation (No.21303043), this paper studies gold nanoparticles and BSA with different surface chemical properties, using UV-Vis absorption spectra (UV-vis) and fluorescence spectra. Circular dichroism (CD) (CD), Fourier transform infrared spectroscopy (CD),) (FTIR), dynamic light scattering (DLS),) transmission electron microscopy (TEM) and other techniques were used to study the interaction between gold nanoparticles with different surface chemical properties and BSA. Fluorescence spectra and UV-vis results reveal the influence of surface chemical properties of gold nanoparticles on the interaction mechanism between gold nanoparticles and BSA. Among them, cysteine, glutathione, PEG (2K) and polypeptide modified nanocrystalline gold interact with BSA to form ground state complex, which is dominated by static quenching. However, PEG (5K) and PEG-COOH (5K) modified nanocrystalline gold do not interact with BSA to form a complex, which is dominated by dynamic quenching. The conformation changes of bovine serum protein with different surface chemical properties of nano-gold before and after interaction were studied by means of synchronous fluorescence spectroscopy and CD,FTIR techniques. The results showed that, PEG (5K) and polypeptide modified nano-gold had little effect on the conformation of BSA, while cysteine, glutathione, PEG (2K) and PEG-COOH (5K), CTAB modified nano-gold had great influence on the secondary structure of BSA. In addition, the thickness of "protein halo" formed on different surface chemical properties of gold nanoparticles was investigated by DLS technique. We found that the surface chemical properties of nanocrystalline gold play an important role in the formation of "protein halo". Finally, the effect of BSA on the aggregation state of gold nanoparticles with different surface chemical properties was studied by UV-vis absorption spectroscopy. The experimental results show that the surface charge of gold nanoparticles is the main factor affecting the aggregation state of gold nanoparticles. The research work has important reference value for further understanding the nature of the interaction between nanomaterials and proteins and the biological effects of nanoparticles.
【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】：O657.3;O641.3
本文编号：2270978
[Abstract]:Protein is the material basis of all life. All kinds of chemical reactions in organism can not be separated from the participation of protein, so it can be said that there is no life activity without protein. Nanocrystalline gold has been widely used in biology, chemistry, medicine, information science and so on because of its unique small size effect, surface effect, optical effect, quantum effect and good biocompatibility. In recent years, nanocrystalline gold has become a hot research topic for researchers. Nanocrystalline gold, as a drug and drug carrier, forms a "protein halo" on its surface, which endows it with new biologic recognition, which changes its physiological reaction and toxicity. Therefore, the study of the interaction between gold nanoparticles with different surface chemical properties and bovine serum albumin (BSA) (BSA) plays an important role in understanding the formation factors of "protein halo" and developing more safe and effective biomaterials. As a part of the project supported by the National Natural Science Foundation (No.21303043), this paper studies gold nanoparticles and BSA with different surface chemical properties, using UV-Vis absorption spectra (UV-vis) and fluorescence spectra. Circular dichroism (CD) (CD), Fourier transform infrared spectroscopy (CD),) (FTIR), dynamic light scattering (DLS),) transmission electron microscopy (TEM) and other techniques were used to study the interaction between gold nanoparticles with different surface chemical properties and BSA. Fluorescence spectra and UV-vis results reveal the influence of surface chemical properties of gold nanoparticles on the interaction mechanism between gold nanoparticles and BSA. Among them, cysteine, glutathione, PEG (2K) and polypeptide modified nanocrystalline gold interact with BSA to form ground state complex, which is dominated by static quenching. However, PEG (5K) and PEG-COOH (5K) modified nanocrystalline gold do not interact with BSA to form a complex, which is dominated by dynamic quenching. The conformation changes of bovine serum protein with different surface chemical properties of nano-gold before and after interaction were studied by means of synchronous fluorescence spectroscopy and CD,FTIR techniques. The results showed that, PEG (5K) and polypeptide modified nano-gold had little effect on the conformation of BSA, while cysteine, glutathione, PEG (2K) and PEG-COOH (5K), CTAB modified nano-gold had great influence on the secondary structure of BSA. In addition, the thickness of "protein halo" formed on different surface chemical properties of gold nanoparticles was investigated by DLS technique. We found that the surface chemical properties of nanocrystalline gold play an important role in the formation of "protein halo". Finally, the effect of BSA on the aggregation state of gold nanoparticles with different surface chemical properties was studied by UV-vis absorption spectroscopy. The experimental results show that the surface charge of gold nanoparticles is the main factor affecting the aggregation state of gold nanoparticles. The research work has important reference value for further understanding the nature of the interaction between nanomaterials and proteins and the biological effects of nanoparticles.
【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】：O657.3;O641.3
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