本文選題：胰高血糖素　切入點(diǎn)：超聲　出處：《寧波大學(xué)》2012年碩士論文　論文類型：學(xué)位論文

【摘要】：蛋白的淀粉樣纖維化聚集與多種疾病密切相關(guān)，如老年癡呆癥等。研究發(fā)現(xiàn)，蛋白纖維的聚集不僅和氨基酸的序列有關(guān)，而且還與外界環(huán)境因素如金屬離子、pH、超聲、溫度等相關(guān)。在本文中，我們的工作主要包含以下兩個(gè)方面：（1）研究胰高血糖素在超聲波影響下的聚集過程。在此工作中，我們利用原子力顯微鏡(AFM)觀察蛋白聚集的形貌，并結(jié)合硫黃素(thioflavin T，，ThT)熒光檢測(cè)其形成淀粉樣纖維的動(dòng)力學(xué)曲線，發(fā)現(xiàn)在超聲波的影響下，胰高血糖素可在較短時(shí)間內(nèi)開始形成淀粉樣纖維，大大縮短了蛋白形成纖維的“醞釀”時(shí)間。而且在不同超聲功率和不同超聲頻率下形成的纖維形貌有較大差異。并用顯微傅立葉變換紅外光譜（Micro-FTIR）對(duì)超聲聚集而成的蛋白纖維的二級(jí)結(jié)構(gòu)進(jìn)行表征。結(jié)果發(fā)現(xiàn)此過程中，蛋白的二級(jí)結(jié)構(gòu)發(fā)生了轉(zhuǎn)變(α螺旋到β折疊)。（2）研究金屬離子對(duì)胰高血糖素淀粉樣蛋白聚集造成的影響。我們主要是利用原子力顯微鏡和顯微傅立葉變換紅外光譜對(duì)加入Fe(Ⅲ)、Cu(Ⅱ)、Fe(Ⅱ)后的胰高血糖素進(jìn)行表征，結(jié)果發(fā)現(xiàn)加入Fe(Ⅲ)后，胰高血糖素蛋白聚集形成淀粉樣纖維的過程進(jìn)行得非常緩慢，而且，經(jīng)過孵化的淀粉樣蛋白的表面形貌以及它的二級(jí)結(jié)構(gòu)都大大地改變了；但是對(duì)于加入Cu(Ⅱ)的樣品，胰高血糖素進(jìn)行纖維化的程度卻變得較快，所得到的表面形貌也顯然不同，不過淀粉樣纖維的二級(jí)結(jié)構(gòu)卻沒怎么有大的改變；對(duì)于摻有Fe(Ⅱ)的蛋白，纖維化過程在速度上沒怎么變化，不過二級(jí)結(jié)構(gòu)卻變了。此外，我們還利用了圓二色譜（CD）和ThT熒光進(jìn)一步對(duì)加入Fe(Ⅲ)、Cu(Ⅱ)后胰高血糖素的聚集過程進(jìn)行研究，關(guān)于其二級(jí)結(jié)構(gòu)的變化與FTIR得出的結(jié)論相同，熒光動(dòng)力學(xué)曲線顯示出加入Fe(Ⅲ)后，蛋白聚集的進(jìn)程被抑制，而加有Cu(Ⅱ)的胰高血糖素的纖維化速度卻在一定程度上提高了。
[Abstract]:The accumulation of amyloid fibrosis is closely related to many diseases, such as Alzheimer's disease. Studies have found that the aggregation of protein fibers is not only related to the sequence of amino acids, but also to environmental factors such as metal ion pH, ultrasound, etc. In this paper, we mainly study the aggregation process of glucagon under the influence of ultrasonic wave. In this work, we use AFM (atomic force microscope) to observe the morphology of protein aggregation. The kinetic curves of the formation of amyloid fibers were determined by fluorescence analysis of thioflavin Th Th. It was found that glucagon could form amyloid fibers in a short time under the influence of ultrasound. The "brewing" time of protein forming fiber was shortened greatly, and the morphology of the fiber formed under different ultrasonic power and frequency was different. Micro-FTIR was used to aggregate the ultrasonic. The secondary structure of the protein fibers was characterized. The secondary structure of the protein was transformed (偽 -helix to 尾 -fold) to study the effect of metal ions on the aggregation of glucagon amyloid protein. We mainly use atomic force microscope (AFM) and micro-Fourier transform infrared spectroscopy (FT-IR) to study the effect of metal ions on the aggregation of glucagon amyloid protein. The glucagon was characterized by adding Fe (鈪

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