利用基質輔助雷射脫附/游離裝置瞭解雙醣分裂片段與功能性碳質材料的關聯

Understanding the Correlation between the Functional Carbonaceous Materials and Disaccharides Fragmentation by Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

李翎潔(Lee Ling-Chieh)

指導教授 ： 鍾博文

國立臺灣師範大學/理學院/化學系/碩士(2017年)

https://doi.org/10.6345/NTNU202202820

摘要

醣類除了是身體主要的能量來源之外，在生物運行上也扮演很重要的腳色。例如醣蛋白是由蛋白質連接醣類而成，廣泛存在於細胞膜表面，目前研究認為在細胞膜上的醣蛋白有傳遞細胞間訊息的功能，也可以阻擋病毒、細菌入侵人體健康的細胞。然而到現在為止，還沒有一個系統化的方法鑑定醣類的結構和組成。為了解決醣類結構鑑定的問題，我們利用基質輔助雷射脫附/游離(MALDI)當游離源和修飾不同酸根的中孔洞碳材(MCN)當基質，試著去分析具有最簡單鍵結結構的雙醣。MALDI有高靈敏度，分析時間短，操作簡單等優點，且不需要在分析前先進行衍生化，是常見分析糖類的離子化方法。由於MALDI是一種軟離子化技術，只能得到完整分子的質譜信息，一般會使用二次質譜的方式得到離子片段，但MCN強大的光學吸收能力及能量傳遞能力可以使分析物得到足夠能量且產生離子碎片，改善傳統使用二次質譜得到離子片段的方法。
我們已經證明利用MCN和具有酸性功能表面的MCN作為基質相較於傳統的有機基質2,5-二羥基苯甲酸（DHB）更適合研究雙醣的分裂片段，實驗結果顯示雙醣的分裂碎片也許會因為（1）MCN的酸性表面官能基催化水解醣類和（2）雙醣在碳質表面上的吸附能量會藉由CH-π相互作用而受到影響。我們希望透過以上兩種因素，分辨具有同分子量而有不同鍵結結構的雙醣。

關鍵字

中孔碳材 ； 吸附 ； 水解 ； 雙醣 ； 分裂片段 ； 基質輔助雷射脫附/游離裝置

並列摘要

Not only does saccharide be the energy source, but also can it play an important role in the human body. For example, glycoprotein which composed of protein linked to saccharides is widely present on the surface of the cell membrane. It has been well studied and suggested that glycoprotein might have governed the function of intercellular information transferring, viruses blocking, and bacteria invading in human cells. However, there was not such a universal method to identify the structural and compositional of saccharides. Herein, to solve aforementioned problem, matrix-assisted laser desorption/ionization was as ion source and acid modified mesoporous carbon nanoparticles (MCN) were employed as matrice to analyze the disaccharide which consist of different orientation and structure. There are many well known advantages for MALDI, such as high sensitivity, short analysis time, simple operation and no derivatization prior to analysis, which lead to be a common method for the characterization of saccharide structure. The secondary mass spectrometry is mainly employed for understanding the fragmentation of the full saccharide molecular in MALDI owing to its limit of soft ionization. Nevertheless, MCN might have advantages of strong optical absorption and high energy transfer capability, which can assist to produce fragmentation of the saccharide simultaneously.
Herein, we have demonstrated using functional MCN as matrice to investigate the characteristic fragments of disaccharides, in comparison with the conventional organic matrix of 2,5-dihydroxybenzoic acid (DHB). Experimental results suggest that the fragmentation might be influenced by (1)the hydrolysis of disaccharides from acidic functional surface of MCN and (2)the adsorption energetic of disaccharides on carbonaceous surface through CH-π interaction. Above all, we have discovered that disaccharides of the same molecular weight with different linkages can be possibly identified through different adsorption and hydrolysis phenomena.

並列關鍵字

Mesoporous carbon material ； Adsorption ； Hydrolysis ； Disaccharide ； Fragment ； MALDI

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