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

authors	Bastos, P; Trindade, F; Ferreira, R; Leite-Moreira, A; Falcao-Pires, I; Manadas, B; Daniel-Da-Silva, AL; Vitorino, R
nationality	International
journal	TALANTA
author keywords	Magnetic Nanoparticles; Proteomics; Urine; Fractionation; Mass spectrometry
keywords	ION AFFINITY-CHROMATOGRAPHY; SELECTIVE ENRICHMENT; TARGETED PROTEOMICS; KIDNEY INJURY; BINDING; DISCOVERY; PHOSPHOPEPTIDES; QUANTIFICATION; BIOMARKERS; CYTOSCAPE
abstract	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.
publisher	ELSEVIER SCIENCE BV
issn	0039-9140
isbn	1873-3573
year published	2017
volume	170
beginning page	81
ending page	88
digital object identifier (doi)	10.1016/j.talanta.2017.03.087
web of science category	Chemistry, Analytical
subject category	Chemistry
unique article identifier	WOS:000402343200012