Laboratory of Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, P.R. China.
Laborotary of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China.
Clin Proteomics. 2014 Jun 5;11(1):25. doi: 10.1186/1559-0275-11-25. eCollection 2014.
Glycoproteins comprise a large portion of the salivary proteome and have great potential for biomarker discovery and disease diagnosis. However, the rate of production and the concentration of whole saliva change with age, gender and physiological states of the human body. Therefore, a thorough understanding of the salivary glycoproteome of healthy individuals of different ages and genders is a prerequisite for saliva to have clinical utility.
Formerly N-linked glycopeptides were isolated from the pooled whole saliva of six age and gender groups by hydrazide chemistry and hydrophilic affinity methods followed by mass spectrometry identification. Selected physiochemical characteristics of salivary glycoproteins were analyzed, and the salivary glycoproteomes of different age and gender groups were compared based on their glycoprotein components and gene ontology.
Among 85 N-glycoproteins identified in healthy human saliva, the majority were acidic proteins with low molecular weight. The numbers of salivary N-glycoproteins increased with age. Fifteen salivary glycoproteins were identified as potential age- or gender-associated glycoproteins, and many of them have functions related to innate immunity against microorganisms and oral cavity protection. Moreover, many salivary glycoproteins have been previously reported as disease related glycoproteins. This study reveals the important role of salivary glycoproteins in the maintenance of oral health and homeostasis and the great potential of saliva for biomarker discovery and disease diagnosis.
糖蛋白构成了唾液蛋白质组的很大一部分，对于生物标志物的发现和疾病诊断具有巨大的潜力。然而，唾液的产生速率和浓度会随着人体的年龄、性别和生理状态而变化。因此，全面了解不同年龄和性别的健康个体的唾液糖蛋白组是唾液具有临床应用的前提。
通过酰肼化学和亲水亲和方法从前人唾液的混合全唾液中分离出 N-连接糖肽，然后通过质谱鉴定进行鉴定。分析了唾液糖蛋白的部分理化特性，并根据糖蛋白成分和基因本体对不同年龄和性别组的唾液糖蛋白组进行了比较。
在健康人唾液中鉴定出的 85 种 N-糖蛋白中，大多数是酸性低分子量蛋白。唾液 N-糖蛋白的数量随年龄增长而增加。15 种唾液糖蛋白被鉴定为潜在的与年龄或性别相关的糖蛋白，其中许多具有与微生物的先天免疫和口腔保护相关的功能。此外，许多唾液糖蛋白以前被报道为与疾病相关的糖蛋白。本研究揭示了唾液糖蛋白在维持口腔健康和体内平衡中的重要作用，以及唾液在生物标志物发现和疾病诊断方面的巨大潜力。
