Cysteine-Functionalized Metal-Organic Framework: Facile Synthesis and High Efficient Enrichment of N-Linked Glycopeptides in Cell Lysate.

Cysteine-functionalized metal-organic framework (MOF) was synthesized via a common and facile two-step method of in situ loading of Au nanoparticles on amino-derived MOF followed by l-cysteine (Cys) immobilization. Owing to the large specific surface area and ultrahigh hydrophilicity of this nanocomposite, excellent performance was observed in the enrichment of N-linked glycopeptides in both model glycoprotein and HeLa cell lysate. By using this nanocomposite, 16 and 31 glycopeptides were efficiently extracted from digest of horseradish peroxidase (HRP) and human serum immunoglobulin G (IgG), respectively.

Online coupling techniques in ambient mass spectrometry.

Since ambient mass spectrometry (AMS) has been proven to have low matrix effects and high salt tolerance, great efforts have been made for online coupling of several analytical techniques with AMS. These analytical techniques include gas chromatography (GC), liquid chromatography (LC), capillary electrophoresis (CE), surface plasmon resonance (SPR), and electrochemistry flow cells. Various ambient ionization sources, represented by desorption electrospray ionization (DESI) and direct analysis in real time (DART), have been utilized as interfaces for the online coupling techniques.

Post-synthetic modification of an amino-functionalized metal-organic framework for highly efficient enrichment of N-linked glycopeptides.

A maltose-functionalized metal-organic framework (MOF), MIL-101(Cr)-maltose, was developed via a simple two step post-synthetic modification of MIL-101(Cr)-NH2. With the use of this nanomaterial, 33 glycopeptides were detected from the digest of human immunoglobulin G, demonstrating its high efficiency in glycoproteomic analysis. More importantly, the generic functionalization route from amino-derived MOFs opens a new perspective in material design in sample preparation.

Recent advances in applications of nanomaterials for sample preparation.

Sample preparation is a key step for qualitative and quantitative analysis of trace analytes in complicated matrix. Along with the rapid development of nanotechnology in material science, numerous nanomaterials have been developed with particularly useful applications in analytical chemistry. Benefitting from their high specific areas, increased surface activities, and unprecedented physical/chemical properties, the potentials of nanomaterials for rapid and efficient sample preparation have been exploited extensively.

Hydrazide functionalized monodispersed silica microspheres: a novel probe with tunable selectivity for a versatile enrichment of phosphopeptides with different numbers of phosphorylation sites in MS analysis.

Hydrazide functionalized monodispersed silica microspheres (HFMSM) were developed for the enrichment of phosphopeptides for the first time. With the aid of the tunable selectivity of HFMSM, global enrichment or fractionation of phosphopeptides with different numbers of phosphorylation sites could be realized by a simple modulation of the concentrations of formic acid in buffers.

Binding constant determination of uranyl-citrate complex by ACE using a multi-injection method.

The binding constant determination of uranyl with small-molecule ligands such as citric acid could provide fundamental knowledge for a better understanding of the study of uranyl complexation, which is of considerable importance for multiple purposes. In this work, the binding constant of uranyl-citrate complex was determined by ACE. Besides the common single-injection method, a multi-injection method to measure the electrophoretic mobility was also applied.

GdF3 as a promising phosphopeptide affinity probe and dephospho-labelling medium: experiments and theoretical explanation.

Bone-like GdF3 was synthesized and applied for phosphopeptide enrichment for the first time. As a new kind of efficient phosphopeptide affinity probe, GdF3 exhibits high efficiency in the mediation of the dephosphorylation reaction. In addition, DFT calculations were introduced to theoretically explain the unique property of GdF3 compared to GdPO4, which is promising and can be potentially significant in protein phosphorylation research.

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

Guanidyl-functionalized graphene (GFG) was designed and synthesized. By simple modulation of the loading buffer this novel bifunctional adsorbent provides two enriching functions, one for global phosphopeptides, and the other for multiphosphopeptides with consecutive phosphorylated residues. GFG provides a promising perspective for consecutive phosphorylated peptide enrichment in phosphor-proteomic research and related biological process studies.

Template-free synthesis of uniform mesoporous SnO nanospheres for efficient phosphopeptide enrichment.

A one-step and template-free method to prepare uniform SnO nanospheres with a mesoporous structure was developed for the applications in phosphopeptide enrichment. The as-synthesized mesoporous SnO nanospheres have a large surface area and highly active surfaces for the effective binding of phosphopeptides. Compared with the non-porous SnO and commercial TiO, mesoporous SnO nanospheres represent superior performance in the specific trapping of phosphopeptides from both standard protein and complex nonfat milk digests for mass spectrometry-based phosphoproteomic analysis.

Novel nanomaterials used for sample preparation for protein analysis.

Sample preparation is of vital importance for proteomic analysis because of the high complexity of biological samples. The rapid development of novel nanomaterials with various compositions, morphologies, and proper surface modifications provides a category of powerful tools for the sample preparation for protein analysis. In this paper, we have summarized recent progresses for the applications of novel nanomaterials in sample preparation for the analysis of proteomes, especially for phosphoproteomes, glycoproteomes, and peptidoms.

SnO(2)-ZnSn(OH)(6): a novel binary affinity probe for global phosphopeptide detection.

ZnSn(OH)(6) and binary-component SnO(2)-ZnSn(OH)(6) were introduced as affinity probes for phosphopeptide enrichment for the first time. Two strategies, either ZnSn(OH)(6) and SnO(2) serial enrichment or binary-component SnO(2)-ZnSn(OH)(6) enrichment in a single run, were proposed to enhance multi-phosphopeptide enrichment and to significantly improve global phosphopeptide detection.