title: Depletion of highly abundant proteins from human cerebrospinal fluid: a cautionary note.
abstract: Affinity-based techniques, both for enrichment or depletion of proteins of interest, suffer from unwanted interactions between the bait or matrix material and molecules different from the original target. This effect was quantitatively studied by applying two common procedures for the depletion of albumin/gamma immunoglobulin to human cerebrospinal fluid. Proteins of the depleted and the column-bound fraction were identified by mass spectrometry, employing (18)O labeling for quantitation of their abundance. To different extents, the depletion procedures caused the loss of proteins previously suggested as biomarker candidates for neurological diseases. This is an important phenomenon to consider when quantifying protein levels in biological fluids.
authors.affiliation: Leibniz Institute of Molecular Pharmacology, Robert-Roessle-Str. 10, D-13125, Berlin, Germany.
authors.forename: Ramona
authors.initials: R
authors.lastname: Günther
authors.affiliation: Leibniz Institute of Molecular Pharmacology, Robert-Roessle-Str. 10, D-13125, Berlin, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.affiliation: Leibniz Institute of Molecular Pharmacology, Robert-Roessle-Str. 10, D-13125, Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schümann
authors.affiliation: Leibniz Institute of Molecular Pharmacology, Robert-Roessle-Str. 10, D-13125, Berlin, Germany.
authors.forename: Ingolf E
authors.initials: IE
authors.lastname: Blasig
authors.affiliation: Leibniz Institute of Molecular Pharmacology, Robert-Roessle-Str. 10, D-13125, Berlin, Germany. haseloff@fmp-berlin.de.
authors.forename: Reiner F
authors.initials: RF
authors.lastname: Haseloff
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis*; D006801:Humans; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D015415:Biomarkers; D002556:Cerebrospinal Fluid Proteins