Analytical Methods
·
2017
·Vol. 10
·期 4
·459-466
·
IF 1.9
Lingyi Zhang,Bingbing Wang,Shulei Wang,Weibing Zhang
In this work, recyclable trypsin immobilized magnetic nanoparticles based on hydrophilic branched polyethylenimine (PEI) modification were synthesized under mild conditions. The amount of the immobilized enzyme was increased greatly by introducing branched PEI onto poly(methacrylic acid) (PMAA) modified Fe3O4 microspheres (denoted as Fe3O4@PMAA@PEI). Trypsin, a model enzyme for this study, was immobilized by Cu2+ with metal chelation to Fe3O4@PMAA@PEI. Compared with Fe3O4@PMAA nanoparticles, the abundant amino groups of the PEI layer not only increased the amount of the immobilized enzyme, but also improved the hydrophilicity of the material to avoid nonspecific protein adsorption. The performance of this material was evaluated by digesting bovine serum albumin (BSA), myoglobin and cytochrome C, followed by MALDI-TOF-MS analysis. Compared with in-solution digestion, not only the sequence coverage was improved (70.0 ± 3.1% vs. 40.0 ± 2.3% for BSA, 92.0 ± 2.4% vs. 81.0 ± 0.8% for myoglobin and 90.0 ± 3.0% vs. 56.0 ± 1.8% for cytochrome C), but also the digestion time was decreased from 24 h to 10 min. Furthermore, the relative standard deviation values (RSDs) of the sequence coverage of BSA were 3.0% for five consecutive digestions and 2.2% for particles from different batches (n = 3), showing good reproducibility. The Fe3O4@PMAA@PEI-trypsin can endure at least 7 times usage and still maintain good digestion performance after being stored at 4 °C for 25 days. When applied to complex samples, more proteins were identified from the extract of a rat liver than in-solution based digestion (582 vs. 496), with a shorter reaction time of 10 min.
研究领域:
生物化学
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
Metabolomics
·
2022
·Vol. 18
·期 11
·1-12
·
IF 4.747
Yang Bo,Yin Hongqing,Wang Jianwei,Gan Jiali,Li Jingfang,Han Rui,Pei Ming,Song Lili,Yang Hongtao
Background Restless legs syndrome (RLS) is a neuromotor disorder, and dialysis patients are more likely to develop RLS. RLS often causes sleep disorders, anxiety and depression in patients. It will increase the risk of death and severely affect the life of patients. At present, RLS has not received enough recognition and attention, and the misdiagnosis rate can reach more than 10%. Methods The discovery set selected 30 peritoneal dialysis (PD) patients and 27 peritoneal dialysis patients with RLS (PD-RLS). A metabolomics method based on ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometric method (UPLC-Q-TOF/MS) was used to analyze the differential metabolites of the two groups. 51 PD patients and 51 PD-RLS patients were included in the validation set. The receiver operating characteristic (ROC) analysis was used to evaluate the early diagnostic biomarkers, and the correlation between the differential metabolites and laboratory test indexes was analyzed to explore the biological function of the differential metabolites. Results Through the integrated analysis, four metabolites can be used as markers for the diagnosis of PD-RLS, including Hippuric acid, Phenylacetylglutamine, N,N,N-Trimethyl-L-alanyl-L-proline betaine and Threonic acid. Through ROC analysis, it is found that they can be used as a metabolic biomarker panel, and the area under the curve of this combination is more than 0.9, indicating that the panel has good diagnostic and predictive ability. Conclusion Metabolomics based on UPLC-Q-TOF/MS technology can effectively identify the potential biomarkers, and provide a theoretical basis for the early diagnosis, prevention and treatment on PD-RLS.
研究领域:
医学
·
代谢组学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 98
·96210-96222
·
IF 3.289
Xing-yu Long,Jia-yuan Li,Dong Sheng,Hong-zhen Lian
The reversible phosphorylation of proteins plays a key role in numerous biological processes, while abnormal phosphorylation is a cause or consequence of many human diseases. Selective enrichment and MALDI-TOF MS or MS/MS characterization and identification of endogenous phosphopeptides fished-out from human saliva sample were achieved using simple and low-cost iron oxide magnetic nanoclusters (Fe3O4 MNCs) affinity probe in this work. The physicochemical properties of the prepared MNCs material was characterized by SEM, TEM, XRD, EDS, SQUID, etc. Based on their merits of high affinity, rapid separation, good biocompatibility, excellent dispersibility and superior specificity for capturing phosphopeptides, the performances of Fe3O4 MNCs were assessed by selectively and efficiently isolating phosphopeptides from standard phosphoprotein and actual non-fat milk tryptic digests, and intricate human saliva, respectively. Moreover, we demonstrated that the probe can be applied for rapid and effective purification and enrichment of phosphoproteins. The Fe3O4 MNCs affinity probe, which possesses the merits of integration of solid Lewis acids function and magnetic property, together with the “double economical” (both time and money) synthesis strategy, should be a promising material for the large scale investigation of endogenous phosphoproteomics.
研究领域:
生物化学
·
蛋白质组学
·
医学诊断
✓ 已验证
DOI
高影响因子
Separations
·
2022
·Vol. 9
·期 6
·140
·
IF 3.344
Xue Li,Wei Wang,Suling Sun,Junhong Wang,Jiahong Zhu,Feng Liang,Yu Zhang,Guixian Hu
A method for quantifying the anthocyanins in grapes was firstly developed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOFMS) combined with quantitative analysis of multi-components by single marker (QAMS). A total of 10 main anthocyanins were analyzed by using peonidin 3-O-glucoside as the reference standard. The accuracy of this method was evaluated by an established and validated external standard quantification method with 10 reference compounds. The standard method difference (SMDs) of the quantification results between QAMS and the external standard methodwasless than 15%. Furthermore, the QAMS method was used to analyzefour batches of grapes and the data was compared with those obtained using the external standard method. No significant difference wasobtained in the results obtained by both methods. These results indicated that the QAMS method could accurately determine the anthocyanins in grapes. This method can provide a basis to address the absence of reference standards for analyzing anthocyanins in other foods.
研究领域:
食品科学
·
分析化学
·
植物学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Zufeng Qiu,Hongsheng Zhao,Kuan Chang,Zhiwei Lin,Qin Kuang,Zhaoxiong Xie
Selective Pt deposition on TiO 2 effectively regulates photogenerated charge separation in MALDI-TOF MS nanomaterial matrices. • Photogenerated holes dominate positive ion mode, while electrons dominate negative, governing small-molecule ionization. • Carrier-dominated mechanism is validated in complex TiO 2 , enabling sensitive detection of representative pollutants. Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) has emerged as a powerful technique for small-molecule analysis with the introduction of inorganic nanomaterial matrices. However, its analytical performance remains highly dependent on matrix-analyte interactions, and a unified mechanistic understanding is still lacking. Here, we demonstrate that selectively deposited Pt/TiO 2 nanomatrices significantly enhance SALDI-TOF MS performance by regulating photogenerated charge carrier dynamics. Facet- and phase-selective Pt deposition promotes the spatial separation and directional migration of photogenerated electron-hole pairs, leading to pronounced signal enhancement in both positive and negative ion modes. Using amino acids as model analytes, facet-selective Pt/TiO 2 affords up to 3.4-fold enhancement for [A + K] + in the positive ion mode and 3.3-fold for [A-H] − in the negative ion mode, outperforming pristine TiO 2 and nonselectively deposited Pt/TiO 2 counterparts. Photo/electro-chemical analyses, including transient photocurrent, electrochemical impedance spectroscopy, and photoluminescence, correlate enhanced charge carrier separation with improved SALDI-TOF MS performance. Scavenger experiments further reveal that photogenerated holes play a dominant role in adduct formation in the positive ion mode, whereas photogenerated electrons govern analyte deprotonation in the negative ion mode. The proposed mechanism is validated in the structurally complex Pt/commercially available TiO 2 (Pt/P25) system via phase-selective Pt deposition, demonstrating its generality. Furthermore, the optimized Pt/TiO 2 matrix achieves sensitive detection of environmental pollutants, including antibiotics and bisphenol A (BPA), achieving a detection limit of 0.1 ppm. This study establishes a clear charge carrier-dominated mechanism for SALDI-TOF MS nanomatrices, provides rational guidance for the design of high-performance matrices, and highlights their practical potential in environmental pollutant analysis. Download: Download high-res image (107KB) Download: Download full-size image
✓ 已验证
DOI
PubMed
高影响因子
Analytical Methods
·
2025
·
IF 2.6
Jiarui Li,Shuai Tang,Hao Wang,Xinhua Guo
The rapid and selective detection of biomarkers for the diagnosis of related diseases still remains a significant challenge due to the complexity of biosamples. Carboxylesterase (CES) is one of the most abundant serine hydrolases in the liver, playing an important role in the metabolism of xenobiotic compounds. In particular, the upregulation of CES is closely associated with hepatocellular carcinoma (HCC), which is a potential biomarker to improve the diagnostic accuracy. Herein, based on the “substrate-hydrolysis enzymatic reaction” strategy, we developed a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) probe, named QF, for the quantitative analysis of CES activity. The QF contained an amide group serving as the enzymatic recognition moiety, and a quinoline tag was introduced to improve the ionization efficiency of both the substrate and its hydrolysis product. Therefore, the CES activity could be directly quantified by the relative intensity ratio of the product and substrate via MALDI-TOF MS without any additional internal standard. Owing to its operating simplicity, high-throughput capacity and quantification accuracy, the proposed method was successfully applied for CES activity quantification, inhibitor screening, and CES activity detection in the cell lysates. This study provides a tool for the rapid detection of CES activity and CES drug development.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2017
·Vol. 55
·期 15
·2537-2543
·
IF 2.952
Jiatao Wu,Chunyan Tan,Xinwen Zhou,Ying Tan,Pengyuan Yang,Yuyang Jiang
Molecular weights of seven poly(phenylene ethynylene)-based water-soluble conjugated polyelectrolytes (CPEs) obtained through Sonogashira coupling are determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A standard sample preparation protocol is developed to characterize the seven CPEs using 2,5-dihydroxybenzoic acid as the matrix (M) and AgTFA as the cationization reagent (CR). High-quality MALDI mass spectra are obtained at volume mixing ratios (CPE/M/CR) of 5/5/1 for anionic polymers (P1–P4) and 5/50/1 for cationic polymers (P5–P7). Molecular weight, molecular weight distribution, and end-group information are analyzed. The effects of molecular weight of CPEs on optical and quenching properties are also studied. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 2537–2543
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD SCIENCE
·
2025
·Vol. 90
·期 1
·e70010
·
IF 3.4
Wanyi Zhang,Qiuqi Peng,Linhan Yuan,Caiwen Wu,Mengqi Wang,Hongbo Li,Hongjuan Li,Jinghua Yu
Infant formulas are constantly being updated and upgraded, and N-glycans are functional glycans that have not been fully exploited to date. Commercial whey protein materials are often used as basic ingredients in infant formulas. Therefore, it is important to study N-glycans in commercial whey protein materials. We used matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and ion chromatography to analyze N-glycans in bovine lactoferrin (Lf), whey protein isolate (WPI), whey protein concentrate 70 (WPC 70), goat whey protein powder 50, demineralized whey powder 90 (D90), and desalted goat whey powder. The results showed that 30, 6, 28, 16, 8, and 9 N-glycans were found in Lf, D90, desalted goat whey powder, WPI, WPC 70, and goat whey protein powder 50, respectively. A total of four structures of N-glycans were detected in this study. Only bovine Lf and WPC 70 contained fucosylated and sialylated binding (SFN-type) glycan structures. Regarding content, WPC 70 showed the highest yield of 14.5 mg/g, and the degree of sialylation was higher than fucosylation. This study provides a potential basis for the future use of commercial whey protein materials in dairy products such as infant formula.
研究领域:
营养学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
Biomed Research International
·
2020
·Vol. 2020
·期 1
·5084057
·
IF 2.276
Li Yang,Yiwei Fang,Ronghua Liu,Junwei He
Dendropanax dentiger root is a traditional medicinal plant in China and used to treat inflammatory diseases for centuries, but its phytochemical profiling and biological functions are still unknown. Thus, a rapid, efficient, and precise method based on ultra high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was applied to rapidly analyse the phytochemical profiling of D. dentiger with anti-inflammatory and antioxidant activities in vitro . As a result, a total of 78 chemical compositions, including 15 phenylpropanoids, 15 alkaloids, 14 flavonoids, 14 fatty acids, 7 phenols, 4 steroids, 4 cyclic peptides, 3 terpenoids, and 2 others, were identified or tentatively characterized in the roots of D . dentiger . Moreover, alkaloid and cyclic peptide were reported from D . dentiger for the first time. In addition, the ethanol crude extract of D. dentiger roots exhibited remarkable anti-inflammatory activity against cyclooxygenase- (COX-) 2 inhibitory and antioxidant activities in vitro . This study is the first to explore the phytochemical analysis and COX-2 inhibitory activity of D. dentiger . This study can provide important phytochemical profiles and biological functions for the application of D. dentiger roots as a new source of natural COX-2 inhibitors and antioxidants in pharmaceutical industry.
研究领域:
天然药物化学
·
药用植物学
·
炎症生物学
·
自由基生物学
·
药物代谢
✓ 已验证
DOI
高影响因子
TALANTA
·
2017
·
IF 4.162
Dandan Jiang,Xiqian Li,Jiutong Ma,Qiong Jia
In this study, we designed a gadolinium-based immobilized metal ion affinity chromatography material for the selective enrichment of phosphopeptides. Gadolinium ion was immobilized on the surface of glutathione-coated magnetic nanoparticles through a facile and effective synthetic route. The adsorbent integrated the advantages of superparamagnetism of Fe 3 O 4 core, good biological compatibility of glutathione , and strong interaction between gadolinium ion and phosphopeptides. It was employed to enrich phosphopeptides from standard protein digests coupled with MALDI-TOF MS. Results demonstrated that the adsorbent possessed high selectivity for phosphopeptides, good reusability and reproducibility. Moreover, the material provided selective enrichment of phosphopeptides from real samples including non-fat milk digests and human serum. The developed method exhibited high sensitivity (detection limit of 10 fmol), showing great potential in the detection of low-abundance phosphopeptides in biological samples.
研究领域:
生物化学
·
分析化学
·
医学检测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MASS SPECTROMETRY
·
2026
·Vol. 61
·期 9
·e70102
·
IF 2.1
Shuyi Wang,Meiying Liu,Ling Ling,Chuan-fan Ding
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis of saccharides, particularly high-molecular-weight polysaccharides, is often hampered by low ionization efficiency. To overcome this limitation, we developed a novel composite matrix comprising 4-hydrazinoquinazoline (4-HQ) and caffeic acid (CA). This matrix synergistically enhances saccharide detection: 4-HQ specifically targets the hemiacetal termini of reducing saccharides via hydrazone formation, thereby improving ionization efficiency, while CA maintains an acidic condition for derivatization and extends the detectable mass range. Using dextran 6 k as a model, we systematically optimized the 4-HQ/CA ratio, reaction temperature, and reaction time. The optimized 4-HQ/CA matrix enabled direct profiling of oligo/polysaccharides in inulin and garlic extracts, as well as N-glycans from ovalbumin and fetuin. Notably, even for non-reducing saccharides where derivatization is precluded, 4-HQ/CA outperformed conventional 2,5-dihydroxybenzoic acid (DHB) by detecting more species with higher signal-to-noise ratios. This versatile composite matrix shows potential for robust analysis of saccharides in glycobiology and food science.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MICROBIOLOGICAL METHODS
·
2026
·
IF 2.5
Weiyi Wu,Yan Zhou,Fan Liu,Yilei Zhu,Zhiwu Dong
Accurate microbial identification based on lipid profiling offers promising applications in diagnostics and microbial ecology. In this study, five lipid pretreatment methods—Maldixin, chloroform–methanol, tert-butyl methyl ether, isobutyric acid–ammonium hydroxide, and sodium acetate (SA) buffer (pH 4.0)—were systematically evaluated using MALDI-TOF mass spectrometry operated in linear negative-ion mode. Among the tested methods, the SA buffer method provided a favorable balance between operational feasibility, extraction efficiency, and spectral quality. Compared with positive-ion mode, negative-ion mode yielded high-intensity lipid peaks and superior spectral clarity, particularly for Acinetobacter baumannii . Lipid profiles were generated from 203 bacterial strains representing six species, revealing distinct species-specific lipid fingerprints. A lipid fingerprint database was subsequently constructed and validated using an independent set of 144 strains, achieving identification accuracies of 81.9% at the species-level and 97.2% at the genus-level. While overall species-level accuracy remains lower than that of conventional protein-based systems, these results indicate that linear negative-ion mode MALDI-TOF MS provides complementary lipid information that may enhance microbial characterization. Further optimization of sample preparation and database algorithms is warranted to support broader clinical application.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）