Issue 9, 2012

A poly(ethylene glycol)-brush decorated magnetic polymer for highly specific enrichment of phosphopeptides

Abstract

Immobilized metal affinity chromatography (IMAC) is a powerful method in phosphopeptide enrichment. However, the achievement of highly specific enrichment and sensitive detection of phosphopeptide by IMAC is still a big challenge because of the lack of high specificity and large binding capacity of conventional IMAC materials. Here, we report a novel IMAC nanoparticle to dramatically improve the enrichment specificity for the phosphopeptide by introducing a titanium phosphate moiety on a poly(ethylene glycol) methacrylate (PEG) brush decorated Fe3O4@SiO2 core–shell nanoparticle (denoted as Fe3O4@SiO2@PEG–Ti4+ IMAC nanoparticle). The thicker grafting layer of the PEG brushes has a higher chelating capacity of titanium ions. Due to the combination of the superior nonfouling property and the enhanced binding capacity of the grafted PEG brushes, the Fe3O4@SiO2@PEG–Ti4+ IMAC nanoparticle demonstrated a high phosphopeptide recovery (over 70%) and low limit of detection (0.5 fmol), along with an exceptional great specificity to capture phosphopeptides from a tryptic digest of the mixture of a nonphosphorylated protein BSA and a phosphorylated protein α-casein with molar ratios of BSA/α-casein up to 2000 : 1. In the analysis of a real complex biological sample, the tryptic digests of Arabidopsis, 2447 unique phosphopeptides have been identified, showing a superior performance of the Fe3O4@SiO2@PEG–Ti4+ IMAC nanoparticle than that of Fe3O4@SiO2–Ti4+ (1186) and commercial TiO2 microspheres (961). We believe that the PEG decoration for IMAC materials will be a convenient approach to significantly improve the specificity and the binding capacity of phosphopeptide enrichment.

Graphical abstract: A poly(ethylene glycol)-brush decorated magnetic polymer for highly specific enrichment of phosphopeptides

Supplementary files

Article information

Article type
Edge Article
Submitted
23 Mar 2012
Accepted
18 Jun 2012
First published
19 Jun 2012

Chem. Sci., 2012,3, 2828-2838

A poly(ethylene glycol)-brush decorated magnetic polymer for highly specific enrichment of phosphopeptides

L. Zhao, H. Qin, Z. Hu, Y. Zhang, R. Wu and H. Zou, Chem. Sci., 2012, 3, 2828 DOI: 10.1039/C2SC20363D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements