C18-functionalized magnetic nanocomposites fabricated by one-step aqueous coating of tailored oligopeptides for enrichment of low-abundance peptides

Abstract

Screening and monitoring endogenous peptides from complicated biosamples is still a major challenge in mass spectrometry-based proteomics research, mainly due to their low concentration and the interference of high-abundance proteins and other contaminants in biological samples. Herein, a facile and novel approach was described for rapid fabrication of C18-functionalized magnetic nanocomposites (C18-MNCs) based on one-step aqueous coating of C18-Val-Lys-Val-Lys-Val-Lys (C18-VK-VI) for the highly selective enrichment of low-abundance endogenous peptides from biological samples. C18-VK-VI can readily self-assemble into complete monolayers mainly composed of β-sheets with C18 hydrophobic chains erecting on the surface of GO@Fe3O4 MNCs under the physiological conditions. The resulting C18VK-VI-GO@Fe3O4 MNCs exhibited good performance for peptides enrichment from digests of standard protein (myoglobin, MYO) and human serum, such as high sensitivity (0.05 fmol μL−1) and selectivity (mass ratio of MYO digests and MYO = 1:500), rapid separation, and good reproducibility. Such a simple mild and rapid one-step aqueous coating method on the basis of oligopeptides self-assembly showed great potential in surface functionalization of various nanoadsorbents for proteome/peptidome researches.