【摘要】：蛋白質(zhì)是一切生命的物質(zhì)基礎(chǔ),生物體內(nèi)的各種化學(xué)反應(yīng)都離不開蛋白質(zhì)的參與,可以說沒有蛋白質(zhì)就沒有生命活動的存在。納米金具有獨特的小尺寸效應(yīng)、表面效應(yīng)、光學(xué)效應(yīng)、量子效應(yīng)以及良好的生物相容性等,在生物、化學(xué)、醫(yī)藥、信息科學(xué)等領(lǐng)域得到了廣泛的應(yīng)用。近年來,納米金已經(jīng)成為科研工作者研究的熱點。納米金作為藥物及藥物載體進入生物體內(nèi),在其表面形成“蛋白暈”,賦予納米金新的生物識別性,從而改變其生理反應(yīng)和毒性。因此,研究不同表面化學(xué)性質(zhì)的納米金與牛血清白蛋白(BSA)的相互作用,對于全面理解“蛋白暈”的形成因素及發(fā)展更為安全有效的生物納米材料具有重要的指導(dǎo)作用。作為國家自然科學(xué)基金(No.21303043)資助課題的一部分,本論文以不同表面化學(xué)性質(zhì)的納米金與BSA作為研究對象,運用紫外-可見吸收光譜(UV-vis)、熒光光譜、圓二色譜(CD)、傅里葉紅外光譜(FTIR)、動態(tài)光散射(DLS)、透射電鏡(TEM)等技術(shù)研究不同表面化學(xué)性質(zhì)的納米金與BSA的相互作用。熒光光譜和UV-vis研究結(jié)果揭示了納米金表面化學(xué)性質(zhì)對其與BSA相互作用機制的影響。其中,半胱氨酸、谷胱甘肽、PEG(2K)及多肽修飾的納米金與BSA相互作用形成了基態(tài)復(fù)合物,以靜態(tài)猝滅為主。而聚合物PEG(5K)、PEG-COOH(5K)修飾的納米金與BSA相互作用不形成復(fù)合物,以動態(tài)猝滅為主。借助同步熒光光譜、CD、FTIR等技術(shù),探討了牛血清蛋白質(zhì)與不同表面化學(xué)性質(zhì)的納米金作用前后構(gòu)象的變化。結(jié)果表明,PEG(5K)及多肽修飾的納米金對BSA構(gòu)象的影響不大,而半胱氨酸、谷胱甘肽、PEG(2K)、PEG-COOH(5K)、CTAB修飾的納米金對BSA的二級結(jié)構(gòu)有較大的影響。此外,運用DLS技術(shù)考察不同表面化學(xué)性質(zhì)的納米金表面所形成的“蛋白暈”厚度。我們發(fā)現(xiàn),納米金的表面化學(xué)性質(zhì)對“蛋白暈”的形成有重要的影響。最后,利用UV-vis吸收光譜研究BSA對不同表面化學(xué)性質(zhì)的納米金聚集狀態(tài)的影響。實驗結(jié)果初步表明,納米金的表面電荷是影響其聚集狀態(tài)的主要因素。本研究工作的開展,對進一步理解納米材料與蛋白質(zhì)相互作用的本質(zhì)及納米粒子的生物學(xué)效應(yīng)具有重要的參考價值。
[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.
【學(xué)位授予單位】：河南師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O657.3;O641.3

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本文編號：2270978