New ammunition for the proteomic reactor: strong anion exchange beads and multiple enzymes enhance protein identification and sequence coverage.
The enrichment and processing of proteomic samples prior to multi-dimensional chromatography remain a challenge in 'gel-free' proteomics. We previously reported the development of a microfluidic device called the "proteomic reactor" that relied on enriching proteins by using strong cation exchange (SCX) followed by trypsin digestion in an interstitial volume as little as 50 nL. Here, we report a novel proteomic reactor that is based on polymeric strong anion exchange (SAX) material to analyse proteomic samples. We also compare the performance of the SAX proteomic reactor to our previously reported SCX proteomic reactor for analysing complex yeast proteomes. Our results indicate that the SAX protein reactor preferentially identifies more acidic peptides and proteins compared to the SCX reactor. We show that the SAX and SCX reactors are complementary and that their combination increases the number of unique peptides and proteins identified by 50%. Furthermore, we show that the number of protein identified can be increased further by up to 40% using different proteolytic enzymes on the proteomic reactor.
Ottawa Institute of Systems Biology, University of Ottawa, Health Sciences Campus, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
Hu
H
Zhou
Weimin
W
Hou
Jean-Philippe
JP
Lambert
Daniel
D
Figeys
D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D002852:Chromatography, Ion Exchange / Q000295:instrumentation* / Q000379:methods; D004798:Enzymes / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods; D040901:Proteomics / Q000295:instrumentation* / Q000379:methods; D015003:Yeasts / Q000737:chemistry*
D000837:Anion Exchange Resins; D004798:Enzymes; D005656:Fungal Proteins