MICROCHIMICA ACTA
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2022
·Vol. 190
·期 1
·1-9
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IF 6.408
Ma Yao,Zhao Liping,Li Linsen,Zhu Chao,Qu Feng
A new type of aptamer-functionalized pH-responsive polymer-modified magnetic nanoparticles (ApMNPs) is introduced for specific enrichment and sensitive determination of lactoferrin (Lf) in complex matrixes. In the construction, Fe 3 O 4 @3-(Triethoxysilyl)propylmethacrylate@poly(4-Vinyl-1, 3-dioxolan-2-one-acrylic acid) (Fe 3 O 4 @MPS@p(VEC-AA)) were synthesized as pH-responsive polymer-modified magnetic nanoparticles (pMNPs) through free radical polymerization to increase the tunable interaction. Lf-binding aptamers were conjugated onto pMNPs through the reaction of amino-group in aptamer and epoxide-group in VEC, innovatively applied to prepare Lf-ApMNPs. On the basis of the synergistic effect of specific affinity of aptamer on Lf and tunable hydrophobic/hydrophilic property of pH-responsive polymer, Lf-ApMNPs presented good selectivity toward Lf, excellent adsorption capacity (as high as 233.9 mg g −1 ), as well as good recoveries in the range 93.6–99.6% in Lf-related nutrition samples. Significantly, the introduction of pH-responsive monomer (AA) effectively regulated the adsorption–desorption process of Lf, with the function similar to a switch. Moreover, the good performances of Ct-ApMNPs toward α-Chymotrypsin showed that ApMNPs exhibited universality to other proteins through easily changing the binding aptamer, thereby offering a facile and efficient approach for specific enrichment and sensitive determination of targets in real biological samples. Graphical Abstract
研究领域:
纳米技术
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分析化学
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生物技术
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOLOGICAL CHEMISTRY
·
2017
·Vol. 292
·期 12
·4789-4800
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IF 4.125
Yun-Bin Han,Liu-Qing Chen,Zhuo Li,Yu-Meng Tan,Yan Feng,Guang-Yu Yang
Endoglycoceramidases (EGCases) specifically hydrolyze the glycosidic linkage between the oligosaccharide and the ceramide moieties of various glycosphingolipids, and they have received substantial attention in the emerging field of glycosphingolipidology. However, the mechanism regulating the strict substrate specificity of these GH5 glycosidases has not been identified. In this study, we report a novel EGCase I from Rhodococcus equi 103S (103S_EGCase I) with remarkably broad substrate specificity. Based on phylogenetic analyses, the enzyme may represent a new subfamily of GH5 glycosidases. The X-ray crystal structures of 103S_EGCase I alone and in complex with its substrates monosialodihexosylganglioside (GM3) and monosialotetrahexosylganglioside (GM1) enabled us to identify several structural features that may account for its broad specificity. Compared with EGCase II from Rhodococcus sp. M-777 (M777_EGCase II), which possesses strict substrate specificity, 103S_EGCase I possesses a longer α7-helix and a shorter loop 4, which forms a larger substrate-binding pocket that could accommodate more extended oligosaccharides. In addition, loop 2 and loop 8 of the enzyme adopt a more open conformation, which also enlarges the oligosaccharide-binding cavity. Based on this knowledge, a rationally designed experiment was performed to examine the substrate specificity of EGCase II. The truncation of loop 4 in M777_EGCase II increased its activity toward GM1 (163%). Remarkably, the S63G mutant of M777_EGCase II showed a broader substrate spectra and significantly increased activity toward bulky substrates (up to >1370-fold for fucosyl-GM1). Collectively, the results presented here reveal the exquisite substrate recognition mechanism of EGCases and provide an opportunity for further engineering of these enzymes.
研究领域:
生物化学
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结构生物学
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酶学
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糖鞘脂学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Wenfen Zhang,Yanhao Zhang,Qiong Jiang,Wenjie Zhao,Ajuan Yu,Hong Chang,Ximei Lu,Fuwei Xie,Baoxian Ye,Shusheng Zhang
To satisfy the requirement of simultaneous extraction and characterization of diverse kinds of multitarget analytes, the preparation, characterization, and application of a novel tetraazacalix[2]arene[2]triazine (TCT) coated magnetic nanoparticle (TCT MNP) adsorbent are presented in this paper. TCT assembles two benzene rings and two triazines with nitrogen cross-bridging links, which exhibits a unique structural framework and versatile recognition features based on the multiple recognition sites. These include π electron stacking, charge transfer, hydrogen bonding, and ion-exchange. TCT MNPs acted as a dispersive SPE adsorbent showing strong interaction with and adsorption of polycyclic aromatic hydrocarbons (PAHs), nitroaromatics, and heavy metal ions. The dispersive magnetic nanoparticle solid phase extraction (d-MNSPE) strategy with the simultaneous extraction and stepwise elution (SESE) procedure was designed and optimized for the five PAHs (phenanthrene, anthracene, pyrene, chrysene, and benzo(a)pyrene), six nitroaromatics (4-nitrotoluene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, 4-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol), and four metal ions (Cu, Zn, Mn, Cd) in aqueous samples. Due to the high stability, desirable durability, larger saturation magnetization, reuse and distinct enrichment capacity of TCT MNPs, the d-MNSPE method with the SESE strategy provided high recovery (>90%) and good precision (relative standard deviations, RSD < 10%). Coupled with the commonly used HPLC-fluorescence detection, HPLC-UV detection, and atomic absorption spectrometry, these trace probes in tap water, river water, and lake water were determined with very low detection limits, in the range of 0.09–0.15 pg mL–1 for PAHs, 6–11 pg mL–1 for nitroaromatics, and 17–53 pg mL–1 for metal ions after being enriched by the d-MNSPE. The determination of trace PAHs in urine samples from smokers and nonsmokers was successfully carried out with this method, which implied that the versatile TCT MNPs and the robust method together represent a significant potential application in the analysis of body fluids and disease markers. Such methods for accurate quantification of trace components in water are very valuable as they fulfill an unmet need in environmental and medicinal chemistry.
研究领域:
分析化学
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环境科学
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材料科学
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药物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemNanoMat
·
2022
·Vol. 8
·期 12
·e202200390
·
IF 3.82
Xueni Shang,Boxue Zhang,Deyu Gao,Mengjia Li,Chenglin Wang,Fanbin Meng,Cong Chen
Graphical A new three-dimensional organic spacer cation, 1,4-diazabicyclo [2,2,2] octane-1,4-diium (DABCO 2+ ) was developed to passivate defects and enhance the device stability. Low-dimensional additive engineering could effectively reduce the high-density trap defect density and improve the stability of perovskite solar cells (PSCs). To avoid the limiting effect of charge carrier transfer by incorporating the large-size long alkyl chain organic cations, we developed a new three-dimensional organic spacer cation, 1,4-diazabicyclo [2,2,2] octane-1,4-diium (DABCO 2+ ), to passivate the defects and enhance the device stability. DABCO 2+ with fine crystal structure and thermal stability could result in substantially fewer structural defects, enhance carrier lifetime, and inhibit nonradiative recombination loss. Structural analysis of CsFAPbI 3 perovskite doped with different concentrations of the three-dimensional organic spacer cations shows a clear correlation between the structure and the resultant perovskite films. Consequently, DABCO 2+ modified CsFAPbI 3 -based PSCs could achieve an optimized PCE of 23.02% with high stability exceeding 1500 h. This work opens a new approach to fabricating PSCs with enhanced stability for future commercial applications.
研究领域:
材料科学
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太阳能
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光伏技术
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）