Abstract

While saliva can be considered as good biological fluid for monitoring biomarkers due to many advantages including its communication with blood and the non-invasive nature during its sampling, its applications to that purpose is still limited. As a part of efforts to expand the applications of saliva to the protein biomarker research, we carried out global absolute quantitation of proteins in human whole saliva (WS) by bottom-up proteomics techniques mainly based on nLC-Q-IMS-TOF employing MSE. From the analyses of a pooled WS sample collected from 22 healthy Korean volunteers, 93 proteins ranging from 5.89×101 ng/mL (immunoglobulin heavy chain) to 1.59×104 ng/mL (α-amylase 1) were confirmed. For the validation of the present results, human serum albumin in the same sample was quantitated by ELISA and its result was compared with that from the nLC-Q-IMS-TOF study. As a result, there was no significant difference between two results from individual approaches (1.18×104 ± 0.03×104 ng/mL from nLC-Q-IMS-TOF experiments vs. 1.23×104 ± 0.07×104 ng/mL from ELISA experiments, n=3, p=0.309). To our knowledge, this is the first global absolute quantitation of proteins in human whole saliva and information from the present study can be widely used as the first level reference for the discovery