While it is known that immunoaffinity depletion of abundant proteins in serum removes additional proteins beyond those targeted, there has been little characterization of the co-depleted proteins in the high abundant fraction, which we refer to here as the "depletome". We present evidence of co-depletion of non-targeted proteins in human serum using a top-20 immunodepletion column, as shown by label-free liquid chromatography mass spectrometry (LC-MS E) profiling. This led to identification of 147 proteins which were specific for this fraction and comprised proteins with functions predominantly in binding and transport of nucleotides, metal ions, carbohydrates and lipids. These results suggest that further studies on this commonly ignored serum fraction may provide new insights into clinical proteomics. Copyright

Depletion, Depletome, MS, Serum, Shotgun proteomics
dx.doi.org/10.1002/jssc.201100060, hdl.handle.net/1765/65799
Journal of Separation Science
This work was funded by the European Commission 7th Framework Programme; grant id fp7/223427 - Developing minimally invasive, tools and technologies for high throughput, low cost molecular assays for the early diagnosis of schizophrenia and other psychiatric disorders (SCHIZDX)
Department of Neuroscience

Koutroukides, T.A, Guest, P.C, Leweke, F.M, Bailey, D.M.D, Rahmoune, H, Bahn, S, & Martins-de-Souza, D. (2011). Characterization of the human serum depletome by label-free shotgun proteomics. Journal of Separation Science, 34(13), 1621–1626. doi:10.1002/jssc.201100060