EDTA-functionalized magnetic nanoparticles: A suitable platform for the analysis of low abundance urinary proteins

作者：Bastos Paulo; Trindade Fabio; Ferreira Rita; Leite Moreira Adelino; Falcao Pires Ines; Manadas Bruno; Daniel da Silva Ana L; Vitorino Rui

来源：Talanta, 2017, 170: 81-88.

DOI：10.1016/j.talanta.2017.03.087

• Magnetic Nanoparticles
• Proteomics
• Urine
• Fractionation
• Mass spectrometry

Urine is a highly attractive source of biological information and disease biomarkers, whose proteome characterization is ongoing. To that end, depletion/enrichment strategies for protein analysis can be of great convenience. We have thus developed a method based on the use of EDTA-functionalized magnetic nanoparticles (NPs@EDTA), to fractionate urine samples before liquid chromatography-mass spectrometry analysis and compared the identified proteins with those obtained from ultrafiltrated/unfractionated (UF) urine samples. NPs@EDTA allowed larger urine volumes to be processed, resulting in a greater number of protein identifications (similar to 2-fold) at a lower cost when compared to UF samples. Proteins of greater abundance (such as albumin and uromodulin) were, at least partially, depleted with NPs@EDTA while those of lower abundance were enriched. Bioinformatics analysis showed that approximately 27% of NPs@EDTA-enriched proteins were annotated as displaying enzymatic activity, most of these being hydrolytic enzymes (56%), particularly proteases/peptidases (48%). Also, post-translational modifications were prominently predicted across NPs@ EDTA-enriched proteins (90%), particularly glycosylation (52%), phosphorylation (47%) and acetylation (30%). NPs@EDTA allowed the identification of 109 proteins in urine for the first time, showing high potential as a platform for urine's fractionation prior to proteomic analysis.

• 出版日期2017-8-1