Facile synthesis of hydrophilic magnetic graphene nanocomposites via dopamine self-polymerization and Michael addition for selective enrichment of N-linked glycopeptides

Abstract

The development of methods to effectively capture N-glycopeptides from the complex biological samples is crucial to N-glycoproteome profiling. Herein, the hydrophilic chitosan-functionalized magnetic graphene nanocomposites (denoted as fe 3 o 4-Go@pDA-chitosan) were designed and synthesized via a simple two-step modification (dopamine self-polymerization and Michael addition). the fe 3 o 4-GO@PDA-Chitosan nanocomposites exhibited good performances with low detection limit (0.4 fmol•μL −1), good selectivity (mixture of bovine serum albumin and horseradish peroxidase tryptic digests at a molar ration of 10:1), good repeatability (4 times), high binding capacity (75 mg•g −1). Moreover, fe 3 o 4-Go@pDA-chitosan nanocomposites were further utilized to selectively enrich glycopeptides from human renal mesangial cell (HRMC, 200 μg) tryptic digest, and 393 N-linked glycopeptides, representing 195 different glycoproteins and 458 glycosylation sites were identified. This study provides a feasible strategy for the surface functionalized novel materials for isolation and enrichment of N-glycopeptides. Protein N-glycosylation, as one of the most prevalent post-translational modifications (PTMs), can significantly change the structure, increase stability and subsequently endow new functions of protein 1-3. Meanwhile, this modification plays determinant roles in physiological processes, such as molecular and cell recognition, signal transduction, immune response. Aberrant protein N-glycosylation is associated with human disease, such as rheumatoid arthritis, lupus erythematosus, Alzheimer's disease (AD) and so on 4-6 Therefore, the thorough analysis of protein N-glycosylation is beneficial for elucidating pathogenesis of many diseases and for the discovery of new clinical biomarkers and effective disease control 7. In the recent years, mass spectrometry (MS) has been widely used in N-glycoproteme analysis due to its high sensitivity and high-throughput and capacity to analyze disease-associated glycoforms 8. However, the low abundance of N-glycoproteins in biological samples, poor ionization of N-glycopeptides and the heterogeneity of glycan structures make the direct MS analysis extremely difficult 8. Therefore, an enrichment step of N-glycopeptides prior to MS analysis is a prerequisite for the successful glycoproteomics analysis. A variety of enrichment strategies towards glycoproteins/glycopeptides have been developed, such as boronic acid chemistry 9-12 , immobilized metal ion affinity chromatography (IMAC) 13-15 , molecularly imprinting

Durable Surfaces from Film-Forming Silver Assemblies for Long-Term Zero Bacterial Adhesion without Toxicity

“…To develop the SAFE coating, we utilized a combination of two different molecular weight hydrophilic polymers (a low molecular weight amine containing polymer (LAP) and an ultrahigh molecular weight antifouling polymer (UAP)) with silver nitrate and a catecholamine. Our choice of the components stems from the current knowledge about catechol chemistry as a robust tool to design diverse functional coatings in combination with polyamines, the reduction of silver salts to nanoparticles in the presence of catechol derivatives, and the interaction of hydrophilic polymers with catecholamine polymers such as polydopamine (PDA). − To address the cumbersome synthesis of the current silver coatings, we developed an all-in-one coating composition that coats surfaces via a one-step process. The lead candidates were identified by utilizing two semi-high-throughput screenings.…”

Green synthesis of quinazoline derivatives using a novel recyclable nano-catalyst of magnetic modified graphene oxide supported with copper

“…They are easily separated from the reaction mixture with an external magnet, easily recycled, and the purification process is easy, due to the simplicity of the recovery operation of magnetic catalysts which is an eco-friendly and green process, have recently received much attention [21][22][23] . It is difficult to separate graphene from the reaction medium by centrifugation and filtration, but if it is combined with iron, it can be easily separated and reused, which has received a lot of attention recently [24][25][26] . Various synthetic methods for magnetized graphene have been proposed, including adding FeCl 3 to a hot mixture of NaOH and diethylene glycol, hydrothermal, ion exchange and subsequent calcination, chemical precipitation, binding Fe 3 O 4 NPs to GO through covalent bonding, and microwave irradiation.…”

Polydopamine as a promising materials platform for next generation thermoplastic-metal structural adhesives

“…[93][94][95][96] Furthermore, dopamine may participate in of several reactions to form covalent bonds with other chemical species. Some examples include condensation reactions, [97][98][99][100] amide bond formation, [101][102][103][104] Michael addition, [105][106][107][108] aryl coupling [109][110][111] , and Schiff base formation. [112][113][114] Finally, the catechol moiety is known to form strong coordination bonds with a wide range of metal atoms.…”