title: Profiling human saliva endogenous peptidome via a high throughput MALDI-TOF-TOF mass spectrometry.
abstract: Establishment of a saliva protein/peptide signature will provide important information for clinical diagnostics and prognosis of human disease. We digested human whole saliva with trypsin to create a tryptic digest salivary peptidome. Proteins/peptides were subsequently identified by high throughput tandem mass spectrometry in conjunction with database searching. Sixty-three saliva peptides corresponding to twenty-two saliva proteins were identified. Thirty of sixty-three saliva peptides with non-specific tryptic cleavage sites were derived from proline-rich proteins, mucin 7, statherin and collagen. Several peptides derived from proline-rich proteins exhibit proline (Pro) - glutamine (Gln) C-termini (-PQ C-termini). Seven peptides with -PQ C-termini were identified in undigested whole saliva, suggesting that peptides with -PQ C-termini indigenously exist in human saliva. Peptides with -PQ C-termini are known to bind oral bacteria and exhibit properties characteristic of innate-immunity peptides. Thus, a saliva peptidome containing peptides with -PQ C-termini, as presented here, may reinforce the development of innate-immunity-related disease monitoring using non-invasive saliva samples and mass spectrometry-based techniques.
authors.affiliation: Division of Dermatology, Department of Medicine, University of California, San Diego, Ca 92161, USA. chunming@ucsd.edu
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Huang
authors.forename: Wenhong
authors.initials: W
authors.lastname: Zhu
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014357:Trypsin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D012471:Salivary Proteins and Peptides; D014357:Trypsin