利用TiO2富集、超滤膜滤过实现了选择性富集和分离磷酸化肽和含唾液酸的N-链接糖肽.首先选取截留分子量为1×104的超滤膜分离糖肽和磷酸化肽,然后利用酪蛋白和牛血清白蛋白的酶解物验证所建立的方法,该方法的最低检出限是0.16 pmol.将上述方法应用于肺癌患者的唾液检测,成功检测并鉴定到8个磷酸化肽和5个糖肽.本方法可有效提高磷酸化肽和糖肽检测的选择性和灵敏度,为疾病生物标志物的检测提供了新方法.
A novel method coupled TiO2 with uhrafiltration membrane was established to enrich and separate phosphopeptides and N-linked glycopeptides. Firstly, the 10K cutoff uhrafihration membrane was chosen for separating phosphopeptides and glycopeptides. Then, TiO2 enrichment and uhrafihration membrane separation of PTM-peptides were tested with tryptic digests of a-casein and bovine fetuin. The limit of detection of the developed method was measured as 0.16 pmol with standard phosphopeptide. At last, the established method was applied to enrich and separate phosphopeptides and glycopeptides from saliva of lung cancer. A total of 8 phosphopeptides and 5 glycopeptides could be successfully identified with nano ultra-high pressure liquid chromatography-quadrupole-time of flight MS (Nano UPLC Q-TOF). This method significantly improved the sensitivity and efficiency and could be contributed to novel disease biomarker discovery.