Development of gel-filter method for high enrichment of low-molecular weight proteins from serum

PLoS One. 2015 Feb 27;10(2):e0115862. doi: 10.1371/journal.pone.0115862. eCollection 2015.

Abstract

The human serum proteome has been extensively screened for biomarkers. However, the large dynamic range of protein concentrations in serum and the presence of highly abundant and large molecular weight proteins, make identification and detection changes in the amount of low-molecular weight proteins (LMW, molecular weight ≤ 30kDa) difficult. Here, we developed a gel-filter method including four layers of different concentration of tricine SDS-PAGE-based gels to block high-molecular weight proteins and enrich LMW proteins. By utilizing this method, we identified 1,576 proteins (n = 2) from 10 μL serum. Among them, 559 (n = 2) proteins belonged to LMW proteins. Furthermore, this gel-filter method could identify 67.4% and 39.8% more LMW proteins than that in representative methods of glycine SDS-PAGE and optimized-DS, respectively. By utilizing SILAC-AQUA approach with labeled recombinant protein as internal standard, the recovery rate for GST spiked in serum during the treatment of gel-filter, optimized-DS, and ProteoMiner was 33.1 ± 0.01%, 18.7 ± 0.01% and 9.6 ± 0.03%, respectively. These results demonstrate that the gel-filter method offers a rapid, highly reproducible and efficient approach for screening biomarkers from serum through proteomic analyses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Proteins / chemistry*
  • Blood Proteins / isolation & purification*
  • Chromatography, Liquid
  • Electrophoresis, Polyacrylamide Gel* / methods
  • Humans
  • Mass Spectrometry
  • Molecular Weight
  • Peptides / chemistry
  • Peptides / isolation & purification
  • Proteome
  • Proteomics / methods

Substances

  • Blood Proteins
  • Peptides
  • Proteome

Grants and funding

This work was supported by: 1. Chinese National Basic Research Programs, Grant No.2011CB910600 & 2013CB911201, http://www.973.gov.cn/English/Index.aspx. 2. National Natural Science Foundation of China, Grant No.31070673 & 31170780, http://www.nsfc.gov.cn/publish/portal1/. 3. National High-Tech Research and Development Program of China, Grant No.SS2012AA020502 & 2011AA02A114, http://www.most.gov.cn/eng/programmes1/200610/t20061009_36225.htm, 4. National Megaprojects for Key Infectious Diseases, Grant No.2013zx10003002, http://www.most.gov.cn/eng/programmes1/200610/t20061008_36198.htm. 5. Key Projects in the National Science & Technology Pillar Program, Grant No.2012BAF14B00, http://www.most.gov.cn/eng/programmes1/200610/t20061009_36224.htm. 6. National Natural Science Foundation of Beijing, Grant No. 5112012, http://www.bjnsf.org/. 7. National Natural Science Foundation of Guangxi, Grant No.2012GXNSFCB53002, http://gxnsf.gxsti.net/stms/login.jsp.