Human saliva proteome: an overview

Abstract

Human saliva contains a rich mixture of biomolecules. Proteins are a major component of this mixture. Given their role as the molecular effectors within biological systems, ranging from catalysis to transport to structure, proteins have great potential as biomarkers of health and disease. The ability to collect these salivary biomarkers easily using non-invasive means makes saliva proteins even more attractive for diagnostic applications. Thousands of proteins are now to be known to be present in human saliva -discovered using proteomic technologies. Emerging technologies are now making it possible to go beyond large-scale cataloging of salivary proteins. These include approaches to catalog protein contributions from the community of microorganisms residing in the oral cavity (metaproteomics) that may reflect the health state of the human host. New mass spectrometry-based proteomics methods are also emerging, shifting the emphasis from large-scale discovery experiments to hypothesis-driven assays for profiling proteins of interest within saliva, enabling validation of their association with specific health conditions. This paper provides a brief overview of efforts to catalog the proteome of human saliva. Recent developments making possible characterization of the metaproteome of human saliva will be discussed, and technologies driving new mass spectrometry-based assays for targeted analysis of proteins within complex samples, such as saliva.