Novel nanomaterials used for sample preparation for protein analysis

An alkali-resistant zirconium-biligand organic framework with dual-metal centers for highly selective capture of phosphopeptides

The stability of MOFs plays one of the most important roles in material applications, while the delicate structure of MOFs suffers from the limitation of poor alkali tolerance. A new biligand Zr-MOF (biUIO-66-NH₂NO₂) with alkali-resistance performance and active functional groups has been synthesized in this study. The biUIO-66-NH₂NO₂ demonstrated a much better stability in 1% NH₃·H₂O solution than its parent material, UIO-66-NH₂. Following further immobilization of Zr⁴⁺ ions, the biDZMOF consisting of dual-zirconium centers was prepared and was further applied in global enrichment of phosphopeptides by avoiding the instability of enrichment materials in the essential alkali elution procedure for the phosphopeptide enrichment workflow. The alkali-resistant elution of phosphopeptides from the biDZMOF can be directly coupled to a tandem mass spectrometry system for peptide analysis without desalting treatment. 425 phosphopeptides in total in 3 independent samples were identified from 10 μL human saliva after enrichment with biDZMOF. The improvement in alkali resistance and successful post-modification of biUIO-66-NH₂NO₂ suggest an efficient strategy to develop new types of MOF materials for application.

Poly-l-lysine-functionalized magnetic graphene for the immobilized metal affinity purification of histidine-rich proteins

Metal affinity-poly-l-lysine functionalization on a magnetic graphene substrate for simultaneously improving the adsorption selectivity toward histidine-rich proteins and inhibiting the non-specific adsorption.

A magnetic nanofiber-based zwitterionic hydrophilic material for the selective capture and identification of glycopeptides

High-performance affinity materials are highly required in the sample preparation process in mass spectrometry-based glycoproteomics studies. In this research, a novel magnetic nanofiber-based zwitterionic hydrophilic material is prepared for glycopeptide enrichment and identification. The one-dimensional hydroxyapatite nanofiber (HN) acted as the supporting substance for immobilizing both Fe3O4 nanoparticles and Au nanoparticles, following the surface modification with a zwitterionic tripeptide l-glutathione (GSH) via the affinity interactions between the thiol group in GSH and both Au and Fe3O4 to form the magHN/Au-GSH nanofiber. Owing to the unique structural features, excellent hydrophilicity, abundant zwitterionic molecules, and strong magnetic responsiveness, the as-prepared magHN/Au-GSH nanofiber possesses satisfactory specificity for glycopeptide enrichment. As a result, the magHN/Au-GSH nanofiber demonstrated great detection sensitivity (2 fmol), satisfying enrichment recovery (89.65%), large binding capacity (100 mg g-1), and high enrichment selectivity (1 : 100) toward glycopeptides. Furthermore, 246 N-glycosylated peptides corresponding to 104 N-glycosylated proteins were identified from only 1 μL human serum, revealing the great potential of this affinity nanofiber for glycopeptide enrichment and glycoproteomics research.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

CeO2-CB nanocomposite as a novel SALDI substrate for enhancing the detection sensitivity of pharmaceutical drug molecules in beverage samples

SALDI-MS analysis of pharmaceutical drug molecules (amitriptyline, imipramine and promazine) using carbon-based substrates, namely, activated charcoal (AC), carbon nanotubes (CNTs), carbon black (CB), graphene (rGO), graphene oxide (GO) and graphite, was explored and compared with the conventional organic matrix of MALDI. CB exhibited superior performance with respect to the other substrates in terms of detection sensitivity. Despite the effectiveness of CB to detect all drug molecules, it demonstrated a number of background signals, which may be an issue for the analysis of other molecules in the future. Therefore, for the first time, a CeO₂-CB nanocomposite was synthesized and applied as a novel SALDI substrate to minimize the background signals and stabilize CB when exposed to high laser power. The nanocomposite was characterized using XRD, TEM, FTIR, UV-Vis and N₂ sorpometry. The spectrum obtained using the novel nanocomposite in the absence of the drug molecules showed minimal background signals compared to CB. Additionally, the CeO₂-CB nanocomposite enhanced the detection sensitivity of the drug molecules with a limit of detection (LOD) of 100 ng/mL. This active substrate nanocomposite was further applied for the analysis of drug-spiked beverages without sample pretreatment or extraction, mimicking cases encountered by forensic toxicologists. All of the drugs and/or their adducts were detected in the drug-spiked beverage samples.

Polymeric ionic liquid-assembled graphene-immobilized silica composite for selective isolation of human serum albumin from human whole blood

Polymeric ionic liquids (PILs) with 1-vinyl-3-ethylimidazolium cations and two different anions of Br^- and PF₆^- were assembled onto the surface of graphene (G) nanosheets. The derived two composites, i.e., PIL(Br)-G and PIL(PF₆)-G, were further efficiently immobilized onto the surface of silica nanoparticles via self-assembly technique. The obtained two PIL-G/SiO₂ nanocomposites exhibited diverse adsorption performances toward proteins through adjusting the anions of PILs. Electrostatic attractions between proteins and the nanocomposites dominated protein adsorption, while the presence of PF₆^- anions weakened electrostatic interactions and deteriorated the selective adsorption of target protein, i.e., bovine serum albumin (BSA) in this case. Specifically, PIL(Br)-G/SiO₂ nanocomposite displayed high selectivity toward BSA and a high adsorption efficiency of ca. 98% was achieved for 100 mg L^-1 BSA in a Britton-Robinson (B-R) buffer at pH 5. HPLC analysis demonstrated the selectivity of PIL(Br)-G/SiO₂ nanocomposite toward BSA in the presence of abundant hemoglobin and cytochrome c. The practical applicability was verified by performing selective isolation of human serum albumin (HSA) from human whole blood. Graphical abstract Selective isolation of human serum albumin from blood by polymeric ionic liquid assembled graphene immobilized silica nanocomposite with tunable anions.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Application of Porous Materials to Carbohydrate Chemistry and Glycoscience

There is a growing interest in using a range of porous materials to meet research needs in carbohydrate chemistry and glycoscience in general. Among the applications of porous materials reviewed in this chapter, enrichment of glycans from biological samples prior to separation and analysis by mass spectrometry is a major emphasis. Porous materials offer high surface area, adjustable pore sizes, and tunable surface chemistry for interacting with glycans, by boronate affinity, hydrophilic interactions, molecular imprinting, and polar interactions. Among the materials covered in this review are mesoporous silica and related materials, porous graphitic carbon, mesoporous carbon, porous polymers, and nanoporous gold. In some applications, glycans are enzymatically or chemically released from glycoproteins or glycopeptides, and the porous materials have the advantage of size selectivity admitting only the glycans into the pores and excluding proteins. Immobilization of lectins onto porous materials of suitable pore size allows for the use of lectin-carbohydrate interactions in capture or separation of glycoproteins. Porous material surfaces modified with carbohydrates can be used for the selective capture of lectins. Controlled release of therapeutics from porous materials mediated by glycans has been reported, and so has therapeutic targeting using carbohydrate-modified porous particles. Additional applications of porous materials in glycoscience include their use in the supported synthesis of oligosaccharides and in the development of biosensors for glycans.

Guanidyl-functionalized graphene as a bifunctional adsorbent for selective enrichment of phosphopeptides

This novel bi-functional gfg provides two enriching performances, one is for global phosphopeptides, and the other is for multi-phosphopeptides with consecutive phosphorylated residues.