American Chemical Society, Journal of Proteome Research, 2(15), p. 647-658, 2016
DOI: 10.1021/acs.jproteome.5b01066
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Plasma membrane (PM) proteins contribute to the identity of a cell, mediate contact and communication and account for more than two thirds of known drug targets1-8. In the past years several protocols for the proteomic profiling of PM proteins have been described. Nevertheless, comparative analyses have mainly focused on different variations of one approach9-11. We compared sulfo-NHS-SS-biotinylation, aminooxy-biotinylation and surface coating with silica beads to isolate PM proteins for subsequent analysis by one-dimensional gel-free liquid chromatography mass spectrometry. Absolute and relative numbers of PM proteins and reproducibility parameters on a qualitative and quantitative level were assessed. Sulfo-NHS-SS-biotinylation outperformed aminooxy-biotinylation and surface coating using silica beads for most of the monitored criteria. We further simplified this procedure by a competitive biotin elution strategy achieving an average PM annotated protein fraction of 54 % (347 proteins). Computational analysis using additional databases and prediction tools revealed that in total over 90 % of the purified proteins were associated with the PM, mostly as interactors. The modified sulfo-NHS-SS-biotinylation protocol was validated by tracking changes in the plasma membrane proteome composition induced by genetic alteration and drug treatment. GPI-anchored proteins were depleted in PM purifications from cells deficient in the GPI transamidase component PIGS; and treatment of cells with tunicamycin significantly reduced the abundance of N-glycoproteins in surface purifications.