Ramachandran Prasanna, Boontheung Pinmannee, Xie Yongming, Sondej Melissa, Wong David T, Loo Joseph A
Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA.
J Proteome Res. 2006 Jun;5(6):1493-503. doi: 10.1021/pr050492k.
Glycoproteins make up a major and important part of the salivary proteome and play a vital role in maintaining the health of the oral cavity. Because changes in the physiological state of a person are reflected as changes in the glycoproteome composition, mapping the salivary glycoproteome will provide insights into various processes in the body. Salivary glycoproteins were identified by the hydrazide coupling and release method. In this approach, glycoproteins were coupled onto a hydrazide resin, the proteins were then digested and formerly N-glycosylated peptides were selectively released with the enzyme PNGase F and analyzed by LC-MS/MS. Employing this method, coupled with in-solution isoelectric focusing separation as an additional means for pre-fractionation, we identified 84 formerly N-glycosylated peptides from 45 unique N-glycoproteins. Of these, 16 glycoproteins have not been reported previously in saliva. In addition, we identified 44 new sites of N-linked glycosylation on the proteins.
糖蛋白构成了唾液蛋白质组的一个主要且重要的部分，在维持口腔健康方面发挥着至关重要的作用。由于人的生理状态变化会反映为糖蛋白组组成的变化，绘制唾液糖蛋白组图谱将有助于深入了解身体的各种过程。唾液糖蛋白通过酰肼偶联和释放法进行鉴定。在这种方法中，糖蛋白与酰肼树脂偶联，然后消化蛋白质，用PNGase F酶选择性释放先前的N-糖基化肽，并通过液相色谱-串联质谱（LC-MS/MS）进行分析。采用这种方法，并结合溶液内等电聚焦分离作为预分级的额外手段，我们从45种独特的N-糖蛋白中鉴定出84个先前的N-糖基化肽。其中，有16种糖蛋白此前未在唾液中报道过。此外，我们还鉴定出了蛋白质上44个新的N-糖基化位点。
