Salivary peptidomics

Abstract

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.

Alteration of Salivary Calcium And Statherin Levels in Patients with Gingivitis And Periodontitis

“…This result reinforces the research in vivo and in situ studies by Amado et al (2010) showed statherin saliva made a major contribution in the formation of pellicle which would develop into plaque. Statherin produced by the parotid and submandibular glands.…”

“…Biomarkers found in saliva potential as diagnostics can be identified if the composition of the protein in the pain compared to healthy individuals, it will describe the specific pathologic condition (Amado et al, 2010). Statherin a carbohydrate-free phosphoprotein very strong binding to the surface of the tooth enamel (Nakagaki et al, 2010).…”

Copy Number Polymorphism of the Salivary Amylase Gene: Implications in Human Nutrition Research

“…Water is the main component of saliva (99%) buffered with electrolytes. A total of approximately 2,000 proteins constitute the salivary peptidome, of which approximately 400–600 are directly derived from salivary glands [3]. The salivary α-amylase represents the major enzyme secreted from the salivary glands [4].…”

Peptidomics of Urine and Other Biofluids for Cancer Diagnostics

“…It lubricates the oral cavity and participates in digestion and preventing infections (27 ). Saliva contains bacteria, cellular debris, crevicular fluid, and serum components, and as an alternative sample for noninvasive collection, saliva has promising, unique features (28 ). Proteolytic degradation occurs as soon as proteins enter the oral cavity and continues after a saliva sample is collected.…”