糖ペプチドのピレン誘導体化MALDI-QIT-TOFMSⁿを利用した新規バイオマーカーの開発

抄録

Glycosylation regulates the biological functions of most proteins. This regulation is caused by not only addition of glycans to the peptides but also alteration of the glycan structures in the status of the cells. Therefore, detection of such alterations is very useful for understanding real-time condition of cells, for example, diseases. Especially, it is widely known that cancer cells produce different glycan structures from normal cells. Analytical method for determination of complicated glycan structures using quite a small amount is the key to developing novel biomarkers. To aim at highly sensitive and simple determination of glycan structures, we have developed negative-MALDI-QIT-TOFMSⁿ analysis after labeling with pyrene derivatives of neutral and acidic oligosaccharides. Introduction of pyrene to oligosaccharides prominently enhances productions of negative ions even from neutral oligosaccharides. MSⁿ analysis of negative ions is very powerful for identification of branched and isomeric oligosaccharides. It was also demonstrated that pyrene-derivatization improves ionization of glycopeptides as well as oligosaccharides but suppresses ionization of peptides. Thanks to the important effects we could detect gycopeptides in practical samples in which only signals of peptides were obtained without prene-derivatization. We have applied this method to various glycoproteins prepared from patient's sera and cleared altered glycosylation. This study is supported by Japan Science and Technology Agency and New Energy and Industrial Technology Development Organization.