Deep Dive on the Proteome of Human Cerebrospinal Fluid: A Valuable Data Resource for Biomarker Discovery and Missing Protein Identification
Charlotte Macron, Lydie Lane, Antonio Nunez Galindo, and Loic Dayon
J. Proteome Res., Article ASAP, published online August 20, 2018
Human cerebrospinal fluid is a window into the brain and a useful source for neurobiological biomarkers for clinical studies. In this paper, the authors have undertaken a comprehensive analysis of a commercial pool of "normal" CSF samples to deeply elucidate the proteome.
The pooled CSF sample was depleted of abundant proteins, labeled with tandem mass tags (TMT), and fractionated in 24 fractions using off-gel electrophoresis. Each fraction was analyzed independently with RP−LC tandem MS (MS/MS).
This shotgun proteomic analysis identified 20,689 peptides mapping on 3379 proteins, and is the largest CSF proteome published so far. Among the CSF proteins identified, 34% correspond to genes whose transcripts are highly expressed in brain according to the Human Protein Atlas. Additionally 26 "missing proteins", predicted by genomic or transcriptomic analyses, were also identified.