Top-down peptidomics of bodily fluids

The naturally occurring peptides, mainly arisingfrom the proteolytic cleavage of larger proteins, playseveral functions within the body (e. g. antihypertensive,immuno-modulatory, anti-microbial and antiviral,mineral carriers). Their presence or the increase of theirconcentration could be connected to different pathologiesand thereby some peptides could be useful biomarkersfor the diagnosis or prognosis of the disease. Peptidomeresearch, particularly within biological fluids, thereforerepresents one of the most interesting and challengingpurposes of proteomics. In this review we describe thecurrent state-of-the-art in peptidomics-based studiesof several human bodily fluids (serum, plasma, urine,cerebrospinal fluid, saliva, tears, seminal fluid, vitreoushumor, pancreatic juice), emphasizing the contributionof top-down proteomic platforms to the deep structuralcharacterization of natural peptides and their posttranslationalmodifications