Embedding an enzyme within a MOF as exoskeleton (enzyme@MOF) offers new opportunities to improve the inherent fragile nature of the enzyme, but also to impart novel biofunctionality to the MOF. ...Despite the remarkable stability achieved for MOF‐embedded enzymes, embedding patterns and conversion of the enzymatic biofunctionality after entrapment by a MOF have only received limited attention. Herein, we reveal how embedding patterns affect the bioactivity of an enzyme encapsulated in ZIF‐8. The enzyme@MOF can maintain high activity when the encapsulation process is driven by rapid enzyme‐triggered nucleation of ZIF‐8. When the encapsulation is driven by slow coprecipitation and the enzymes are not involved in the nucleation of ZIF‐8, enzyme@MOF tends to be inactive owing to unfolding and competing coordination caused by the ligand, 2‐methyl imidazole. These two embedding patterns can easily be controlled by chemical modification of the amino acids of the enzymes, modulating their biofunctionality.
Suit of armor: The effects of embedding patterns on the biofunctionality of MOF‐encapsulated enzymes are releaved. This work demostrates that the embedding patterns can easily be controlled through enzyme‐surface modification as a new strategy to construct enzymes@MOFs with excellent bioactivity and stability.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Nature programs the structural folding of an enzyme that allows its on-demand biofunctionality; however, it is still a long-standing challenge to manually modulate an enzyme's conformation. Here, we ...design an exogenous hydrogen-bonded organic framework to modulate the conformation of cytochrome c, and hence allow non-native bioactivity for the enzyme. The rigid hydrogen-bonded organic framework, with net-arranged carboxylate inner cage, is in situ installed onto the native cytochrome c. The resultant hydrogen-bonded nano-biointerface changes the conformation to a previously not achieved catalase-like species within the reported cytochrome c-porous organic framework systems. In addition, the preserved hydrogen-bonded organic framework can stabilize the encapsulated enzyme and its channel-like pores also guarantee the free entrance of catalytic substrates. This work describes a conceptual nanotechnology for manoeuvring the flexible conformations of an enzyme, and also highlights the advantages of artificial hydrogen-bonded scaffolds to modulate enzyme activity.
Functionalized magnetic nanoparticles have attracted much attention in sample preparation because of their excellent performance compared with traditional sample-preparation sorbents. In this review, ...we describe the application of magnetic nanoparticles functionalized with silica, octadecylsilane, carbon-based material, surfactants, and polymers as adsorbents for separation and preconcentration of analytes from a variety of matrices. Magnetic solid-phase extraction (MSPE) techniques, mainly reported in the last five years, are presented and discussed.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The determination of endogenous substances is of great significance for obtaining important biotic information such as biological components, metabolic pathways and disease biomarkers in different ...living organisms (e.g. plants, insects, animals and humans). However, due to the complex matrix and the trace concentrations of target analytes, the sample preparation procedure is an essential step before the analytes of interest are introduced into a detection instrument. Solid-phase microextraction (SPME), an emerging sample preparation technique that integrates sampling, extraction, concentration, and sample introduction into one step, has gained wide acceptance in various research fields, including in the determination of endogenous compounds. In this review, recent developments and applications of SPME for the determination of endogenous substances over the past five years are summarized. Several aspects, including the design of SPME devices (sampling configuration and coating), applications (in vitro and in vivo sampling), and coupling with emerging instruments (comprehensive two-dimensional gas chromatography (GC × GC), ambient mass spectrometry (AMS) and surface enhanced Raman scattering (SERS)) are involved. Finally, the challenges and opportunities of SPME methods in endogenous substances analysis are also discussed.
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•Recent developments and applications of SPME for the determination of endogenous substances are summarized.•Novel SPME devices, workflow forms and the strategies for coupling SPME with emerging instruments are introduced.•The challenges and opportunities of SPME method for the determination of endogenous substances are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Crystallization of biomacromolecules-metal-organic frameworks (BMOFs) allows for orderly assemble of symbiotic hybrids with desirable biological and chemical functions in one voxel. The ...structure-activity relationship of this symbiotic crystal, however, is still blurred. Here, we directly identify the atomic-level structure of BMOFs, using the integrated differential phase contrast-scanning transmission electron microscopy, cryo-electron microscopy and x-ray absorption fine structure techniques. We discover an obvious difference in the nanoarchitecture of BMOFs under different crystallization pathways that was previously not seen. In addition, we find the nanoarchitecture significantly affects the bioactivity of the BMOFs. This work gives an important insight into the structure-activity relationship of BMOFs synthesized in different scenarios, and may act as a guide to engineer next-generation materials with excellent biological and chemical functions.
Photosynthesis of hydrogen peroxide (H
O
) in ambient conditions remains neither cost effective nor environmentally friendly enough because of the rapid charge recombination. Here, a photocatalytic ...rate of as high as 114 μmol⋅g
⋅h
for the production of H
O
in pure water and open air is achieved by using a Z-scheme heterojunction, which outperforms almost all reported photocatalysts under the same conditions. An extensive study at the atomic level demonstrates that Z-scheme electron transfer is realized by improving the photoresponse of the oxidation semiconductor under visible light, when the difference between the Fermi levels of the two constituent semiconductors is not sufficiently large. Moreover, it is verified that a type II electron transfer pathway can be converted to the desired Z-scheme pathway by tuning the excitation wavelengths. This study demonstrates a feasible strategy for developing efficient Z-scheme photocatalysts by regulating photoresponses.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
B cells consistently represent abundant cellular components in tumors; however, direct evidence supporting a role for B cells in the immunopathogenesis of human cancers is lacking, as is specific ...knowledge of their trafficking mechanisms. Here, we demonstrate that chemokine (C‐X‐C motif) receptor 3–positive (CXCR3+) B cells constitute approximately 45% of B‐cell infiltrate in human hepatocellular carcinoma (HCC) and that their levels are positively correlated with early recurrence of HCC. These cells selectively accumulate at the invading edge of HCC and undergo further somatic hypermutation and immunoglobulin G–secreting plasma cell differentiation. Proinflammatory interleukin‐17+ cells are important for the induction of epithelial cell–derived CXCR3 ligands CXCL9, CXCL10, and CXCL11, which subsequently promote the sequential recruitment and further maturation of CXCR3+ B cells. More importantly, we provide evidence that CXCR3+ B cells, but not their CXCR3– counterparts, may operate in immunoglobulin G–dependent pathways to induce M2b macrophage polarization in human HCC. Depletion of B cells significantly suppresses M2b polarization and the protumorigenic activity of tumor‐associated macrophages and restores the production of antitumorigenic interleukin‐12 by those cells in vivo. Conclusion: Selective recruitment of CXCR3+ B cells bridges proinflammatory interleukin‐17 response and protumorigenic macrophage polarization in the tumor milieu, and blocking CXCR3+ B‐cell migration or function may help defeat HCC.(Hepatology 2015;62:1779–1790)
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Enrichments of emerging pollutants and drugs from various samples with complex matrices make it urgent and challenging to develop novel SPME coatings, and the flourishing materials with high ...enrichment capabilities provide good opportunities for it. This review summarizes the used materials for the fabrication of SPME coatings in the past five years, including carbon, polymer, metal organic frameworks (MOFs), covalent organic frameworks (COFs), ionic liquids (ILs), metal/metal oxide nanoparticles and silica. To obtain SPME coatings with excellent physical performance, anti-interference ability and high enrichment capability, suitable coating methods and supports are selected according to the properties of coating materials. In addition, the factors of coating materials and analytes influencing the enrichment effect are summarized and illustrated preliminarily, benefiting for further design of advanced coating materials with enhanced performance.
•A variety of new materials employed as novel fiber coatings have been summarized.•The coating methods have been reviewed according to the property of selected material.•The enrichment mechanisms of coating materials have been illustrated preliminarily.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Recent studies have demonstrated that ubiquitin‐specific protease 10 (USP10) plays a catalytic role in tumour suppression mainly by deubiquitinating its target proteins to enhance their stabilities. ...However, we found that USP10 could interact with and regulate the expression of oncogenic factor Musashi‐2 (MSI2). We investigated whether USP10 positively regulates the expression of MSI2 by deubiquitination and confirmed the type of polyubiquitin chain that is linked to MSI2. We also explored the role of USP10 in regulating the proliferation of colon cancer through different experiments. This study provides a completely new perspective in understanding the role of USP10 in deubiquitination. In the future, USP10 may serve as a target for colon cancer treatment.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•Applications of nanomaterials in SPE and SPME are summarized and discussed.•Adsorption characters of metallic NPs and MOF nanomaterials are introduced.•Extraction applications of carbonaceous and ...siliceous nanomaterials are presented.
Nanotechnology is one of the most important trends in material science. Due to the ultra-small size, nanomaterials possess unique physical and chemical properties. In this review, we summarized and discussed the recent applications of different nanomaterials, including metallic nanoparticles, metal organic frameworks (MOFs) materials, carbonaceous nanomaterials and siliceous nanoparticles, in sample preparation techniques.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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