Comparative human salivary and plasma proteomes

Abstract

The protein compositions, or the proteomes, found in human salivary and plasma fluids are compared. From recent experimental work by many laboratories, a catalogue of 2290 proteins found in whole saliva has been compiled. This list of salivary proteins is compared with the 2698 proteins found in plasma. Approximately 27% of the whole-saliva proteins are found in plasma. However, despite this apparent low degree of overlap, the distribution found across Gene Ontological categories, such as molecular function, biological processes, and cellular components, shows significant similarities. Moreover, nearly 40% of the proteins that have been suggested to be candidate markers for diseases such as cancer, cardiovascular disease, and stroke can be found in whole saliva. These comparisons and correlations should encourage researchers to consider the use of saliva to discover new protein markers of disease and as a diagnostic non-proximal fluid to detect early signs of disease throughout the body.

Figures

Figure 1.

Venn diagram showing the overlapping protein identifications among plasma, whole saliva, and parotid/SM/SL.

Figure 2.

Array views of the human salivary and plasma proteomes. The view on the left is sorted according to the salivary proteins with highest percentage sequence coverage (indicated by the red bars), and the view on the right is sorted by the plasma proteins with highest sequence coverage. Proteins with low sequence coverage are indicated by the green bars.

Figure 3.

GO distributions (cellular component, top; biological process, middle; molecular function, bottom) of proteins in whole saliva (WS), plasma (Plasma), proteins unique to only whole saliva (WS_only) and plasma (Plasma_only), and proteins found in both whole saliva and plasma (WS_Plasma).