Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal.
Expert Rev Proteomics. 2010 Oct;7(5):709-21. doi: 10.1586/epr.10.48.
In recent years, there has been an increased interest in the study of saliva. This bodily fluid contains a vast number of protein species, the salivary peptidome, of low molecular weight, comprising approximately 40-50% of the total secreted proteins, in addition to peptides generated by proteolysis of proteins of different sources. Owing to the presence of other components, in particular mucins and enzymes, some distinctive requirements and precautions related to sample collection, time of analysis, sample preservation and treatment are necessary for the successful analysis of salivary peptides. More than 2000 peptides compose the salivary peptidome, from which only 400-600 are directly derived from salivary glands, suggesting an important qualitative peptide contribution of other sources, namely of epithelial cells. Proteolysis events are the main supply for the peptidome and considerable efforts have been made to identify the resulting fragments, the cleavage sites and the involved proteases. The salivary proteins more prone to proteolysis are proline-rich proteins (PRPs; acidic PRPs and basic PRPs), statherin, histatins and P-B peptide. Gln-Gly cleavages are largely associated with PRP classes, while Tyr-Gly cleavages are related to histatin 1 and to the P-B peptide. The interest in saliva has been growing for clinical purposes, as it is an alternative sample to other traditional bodily fluids, such as blood or urine, since it involves an easy and noninvasive collection. In fact, apart from its usefulness as a source of information for the prognosis, diagnosis and treatment of oral diseases, such as Sjögren's syndrome, gum disease, tooth decay or oral cancer, saliva might also be seen as a potential tool to the diagnosis of systemic diseases. Owing to the enormous amount of previously discovered salivary peptide species, in this article, we attempt to harmonize the nomenclature, following International Union of Pure and Applied Chemistry recommendations.
近年来，人们对唾液的研究兴趣日益浓厚。这种体液中含有大量低分子量的蛋白质种类，即唾液肽组，占总分泌蛋白的 40-50%，此外还有不同来源蛋白质的蛋白水解生成的肽。由于存在其他成分，特别是粘蛋白和酶，因此需要对样本采集、分析时间、样本保存和处理等方面进行一些独特的要求和注意事项，以确保唾液肽的成功分析。唾液肽组由超过 2000 种肽组成，其中只有 400-600 种直接来源于唾液腺，这表明其他来源，即上皮细胞，对肽的质量有重要贡献。蛋白水解事件是肽组的主要供应来源，人们已经做出了相当大的努力来识别所得片段、切割位点和涉及的蛋白酶。更易发生蛋白水解的唾液蛋白是富含脯氨酸的蛋白（PRP；酸性 PRP 和碱性 PRP）、牙本质基质蛋白、组蛋白和 P-B 肽。Gln-Gly 切割主要与 PRP 类相关，而 Tyr-Gly 切割与组蛋白 1 和 P-B 肽相关。由于唾液是一种替代其他传统体液（如血液或尿液）的样本，因为它涉及到一种简单、非侵入性的采集方式，因此其在临床方面的应用兴趣日益浓厚。事实上，除了作为预测、诊断和治疗口腔疾病（如干燥综合征、牙龈疾病、龋齿或口腔癌）的信息来源外，唾液也可能被视为诊断系统性疾病的潜在工具。由于之前已经发现了大量的唾液肽种类，因此在本文中，我们尝试根据国际纯粹与应用化学联合会的建议，使命名法协调一致。
