Publications (38) View all
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Article: 1-(3-Aminopropyl)-3-butylimidazolium bromide for carboxyl group derivatization: potential applications in high sensitivity peptide identification by mass spectrometry.
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ABSTRACT: The cationic reagent 1-(3-aminopropyl)-3-butylimidazolium bromide (BAPI) was exploited for the derivatization of carboxyl groups on peptides. Nearly 100% derivatization efficiency was achieved with the synthetic peptide RVYVHPI (RI-7). Furthermore, the peptide derivative was stable in a 0.1% TFA/water solution or a 0.1% (v/v) TFA/acetonitrile/water solution for at least one week. The effect of BAPI derivatization on the ionization of the peptide RI-7 was further investigated, and the detection sensitivity was improved >42-fold via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), thus outperforming the commercial piperazine derivatization approach. Moreover, the charge states of the peptide were largely increased via BAPI derivatization by electrospray ionization (ESI) MS. The results indicate the potential merits of BAPI derivatization for high sensitivity peptide analysis by MS.Science China. Life sciences 03/2013; 56(3):240-5. · 2.02 Impact Factor -
Article: Aptamer Modified Organic-Inorganic Hybrid Silica Monolithic Capillary Columns for Highly Selective Recognition of Thrombin.
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ABSTRACT: A novel kind of aptamer modified organic-inorganic hybrid silica monolithic capillary column has been developed, via the covalent bonding of 5'-NH2-modified aptamer for human α-thrombin on hybrid silica monolith, prepared by sol-gel method, with tetraethoxysilane and 3-aminopropyltriethoxysilane as precursors. Due to the large specific surface area of the hybrid matrix, the average coverage density of aptamer reached 568 pmol/μL, and the thrombin binding capacity was 1.15 μg/μL, 14 times higher than that of aptamer modified open tubular capillaries. By such an affinity capillary column, the limit of detection of thrombin was decreased to 3.4 nM with a UV detector. Furthermore, even when thrombin was mixed with 1000 times more concentrated human serum, it could be selectively enriched and detected with the signal to noise ratio as ca.10. These results indicate that the developed preparation strategy for aptamer based hybrid silica monolithic capillary column might provide an effective method to achieve high selective recognition of trace targets.Analytical Chemistry 11/2012; · 5.86 Impact Factor -
Article: Hydrophilic immobilized trypsin reactor with magnetic graphene oxide as support for high efficient proteome digestion.
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ABSTRACT: In this paper, magnetic Fe₃O₄ nanoparticles modified graphene oxide nanocomposites (GO-CO-NH-Fe₃O₄) were prepared by covalent bonding, via the reaction between the amino groups of fuctionalized Fe₃O₄ and the carboxylic groups of GO, confirmed by Fourier-transform infrared spectra, Raman spectroscopy, and transmission electron microscopy. With GO-CO-NH-Fe₃O₄ as a novel substrate, trypsin was immobilized via π-π stacking and hydrogen bonding interaction, and the binding capacity of trypsin reached as high as 0.275 mg/mg. Since GO-CO-NH-Fe₃O₄ worked as not only support for enzyme immobilization, but also as an excellent microwave irradiation absorber, the digestion efficiency could be further improved with microwave assistance. By such an immobilized enzymatic reactor (IMER), standard proteins could be efficiently digested within 15 s, with sequence coverages comparable or better than those obtained by conventional in-solution digestion (12 h). Since trypsin was immobilized under mild conditions, the enzymatic activity of IMER preserved at least for a month. In addition, due to the good hydrophilicity of GO, no peptide residue was observed in the sequent digestion of bovine serum albumin and myoglobin. To further confirm the efficiency of such an IMER for proteome analysis, it was applied to digest proteins extracted from rat liver, followed by nanoRPLC-ESI-MS/MS analysis. With only 5 min microwave-assisted digestion, in 3 parallel runs, totally 456 protein groups were identified, comparable to that obtained by 12 h in-solution digestion, indicating the great potential of IMERs with GO-CO-NH-Fe₃O₄ as the support for high throughput proteome study.Journal of chromatography. A 07/2012; 1254:8-13. · 4.19 Impact Factor -
Article: Boronic Acid functionalized core-shell polymer nanoparticles prepared by distillation precipitation polymerization for glycopeptide enrichment.
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ABSTRACT: The boronic acid-functionalized core-shell polymer nanoparticles, poly(N,N-methylenebisacrylamide-co-methacrylic acid)@4-vinylphenylboronic acid (poly(MBA-co-MAA)@VPBA), were successfully synthesized for enriching glycosylated peptides. Such nanoparticles were composed of a hydrophilic polymer core prepared by distillation precipitation polymerization (DPP) and a boronic acid-functionalized shell designed for capturing glycopeptides. Owing to the relatively large amount of residual vinyl groups introduced by DPP on the core surface, the VPBA monomer was coated with high efficiency, working as the shell. Moreover, the overall polymerization route, especially the use of DPP, made the synthesis of nanoparticles facile and time-saving. With the poly(MBA-co-MAA)@VPBA nanoparticles, 18 glycopeptides from horseradish peroxidase (HRP) digest were captured and identified by MALDI-TOF mass spectrometric analysis, relative to eight glycopeptides enriched by using commercially available meta-aminophenylboronic acid agarose under the same conditions. When the concentration of the HRP digest was decreased to as low as 5 nmol, glycopeptides could still be selectively isolated by the prepared nanoparticles. Our results demonstrated that the synthetic poly(MBA-co-MAA)@VPBA nanoparticles might be a promising selective enrichment material for glycoproteome analysis.Chemistry 06/2012; 18(29):9056-62. · 5.93 Impact Factor -
Article: Mesoporous TiO2 aerogel for selective enrichment of phosphopeptides in rat liver mitochondria.
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ABSTRACT: The enrichment of low abundance phosphopeptides before MS analysis is a critical step for in-depth phosphoproteome research. In this study, mesoporous titanium dioxide (TiO(2)) aerogel was prepared by precipitation and supercritical drying. The specific surface area up to 490.7 m(2) g(-1) is achieved by TiO(2) aerogel, much higher than those obtained by commercial TiO(2) nanoparticles and by the latest reported mesoporous TiO(2) spheres. Due to the large specific surface area and the mesoporous structure of the aerogel, the binding capacity for phosphopeptides is six times higher than that of conventional TiO(2) microparticles (173 vs 28 μmol g(-1)). Because of the good compatibility of enrichment procedure with MALDI-TOF-MS and the large binding capacity of TiO(2) aerogel, a detection limit as low as 30 amol for analyzing phosphopeptides in β-casein digest was achieved. TiO(2) aerogel was further applied to enrich phosphopeptides from rat liver mitochondria, and 266 unique phosphopeptides with 340 phosphorylation sites, corresponding to 216 phosphoprotein groups, were identified by triplicate nanoRPLC-ESI-MS/MS runs, with false-positive rate less than 1% at the peptide level. These results demonstrate that TiO(2) aerogel is a kind of promising material for sample pretreatment in the large-scale phosphoproteome study.Analytica chimica acta 06/2012; 729:26-35. · 4.31 Impact Factor
