title: Peptidomic analysis of human reflex tear fluid.
abstract: Tear fluid is a complex mixture of biological compounds, including carbohydrates, lipids, electrolytes, proteins, and peptides. Despite the physiological importance of tear fluid, little is known about the identity of its endogenous peptides. In this study, we analyzed and identified naturally occurring peptide molecules in human reflex tear fluid by means of LC-MALDI-TOF-TOF. Tandem MS analyses revealed 30 peptides, most of which have not been identified before. Twenty-six peptides are derived from the proline-rich protein 4 and 4 peptides are derived from the polymeric immunoglobulin receptor. Based on their structural characteristics, we suggest that the identified tear fluid peptides contribute to the protective environment of the ocular surface.
authors.affiliation: Research Group of Functional Genomics and Proteomics, KU Leuven, B-3000 Leuven, Belgium. Eisuke.Hayakawa@bio.kuleuven.be
authors.forename: Eisuke
authors.initials: E
authors.lastname: Hayakawa
authors.forename: Bart
authors.initials: B
authors.lastname: Landuyt
authors.forename: Geert
authors.initials: G
authors.lastname: Baggerman
authors.forename: Ruud
authors.initials: R
authors.lastname: Cuyvers
authors.forename: Rob
authors.initials: R
authors.lastname: Lavigne
authors.forename: Walter
authors.initials: W
authors.lastname: Luyten
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D055233:Cornified Envelope Proline-Rich Proteins / Q000032:analysis / Q000737:chemistry; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D019056:Receptors, Polymeric Immunoglobulin / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D013666:Tears / Q000737:chemistry*
chemical_list: D055233:Cornified Envelope Proline-Rich Proteins; D010455:Peptides; D019056:Receptors, Polymeric Immunoglobulin