APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 102
·期 18
·7891-7900
·
IF 3.34
Pei Xiaolin,Wang Jiapao,Wu Yifeng,Zhen Xiaoting,Tang Manman,Wang Qiuyan,Wang Anming
Nitrile hydratase (NHase) has attracted considerable attention since it can efficiently catalyze the hydration of nitriles to valuable amides. However, the poor stability of NHase is one of the main drawbacks in the industrial application. In this study, we compared the structural difference between Fe-type and Co-type NHase and found that an extra α helix existed at the β-subunit surface of Co-type NHase (defined as the β-6th helix). Then, the effects of the β-6th helix were investigated on the thermal stability and the catalytic kinetics of a Co-type NHase from Aurantimonas manganoxydans ATCC BAA-1229 (NHase1229). When the β-6th helix was deleted or disrupted, the thermal stability of NHase1229 was reduced to 17.6 and 12.9% of that of wild NHase1229, respectively. Thus, the β-6th helix is important for the thermal stability of Co-type NHase. Based on the structural characteristics of Co-type NHase, the β-6th helix may be interacted with another helix at the α-subunit (defined as the α-2nd helix) by hydrophobic network just as a “magnetic suction buckle” on the enzyme surface to stabilize the binding of α- and β-subunits. The β-6th helix is located at the mouth of the substrate and product tunnel, so it plays crucial roles in catalytic process. Furthermore, the β-6th helix in NHase1229 was swapped with a thermophilic NHase fragment from Pseudonocardia thermophila JCM3095 (NHase1229-Swap). The thermal stability of NHase1229-Swap was significantly improved, and the half-life was approximately 2.4-fold at 40 °C than that of the wild NHase1229. The knowledge is useful for improving the stability of NHases by restriction fragment swapping.
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PubMed
高影响因子
Pharmaceutics
·
2020
·Vol. 12
·期 2
·111
·
IF 4.421
Weinan Li,Jialin Sun,Xiaoyu Zhang,Li Jia,Mingxi Qiao,Xiuli Zhao,Haiyang Hu,Dawei Chen,Yanhong Wang
PEG-poly(β-amino ester) (PEG-PBAE), which is an effective pH-responsive copolymer, was mainly synthesized by Michael step polymerization. Thioridazine (Thz), which was reported to selectively eliminate cancer stem cells (CSCs), was loaded into PEG-PBAE micelles (PPM) prepared by self-assembly at low concentrations. The critical micelle concentrations (CMC) of PPM in water were 2.49 μg/mL. The pH-responsive PBAE segment was soluble due to protonated tertiary amine groups when the pH decreased below pH 6.8, but it was insoluble at pH 7.4. The Thz-loaded PEG-PBAE micelle (Thz/PPM) exhibited a spherical shape, and the drug loading was 15.5%. In vitro release of Thz/PPM showed that this pH-sensitivity triggered the rapid release of encapsulated Thz in a weakly acidic environment. The in vitro cytotoxicity and cellular uptake of various formulations at pH 7.4 and 5.5 were evaluated on the mammospheres (MS), which were sorted by MCF-7 human breast cancer cell lines and identified to be a CD44+/CD24−phenotype. The results of the cytotoxicity assay showed that blank micelles were nontoxic and Thz/PPM exhibited a similar anti-CSC effect on MS compared to Thz solution. Stronger fluorescence signal of Coumarin-6 (C6) was observed in MS treated by C6-loaded PPM (C6/PPM) at pH 5.5. The tumor inhibition rate and tumor weight of the free DOX and Thz/PPM groups were significantly different from those of the other groups, which free DOX and Thz/PPM effectively suppressed breast tumor growth in vivo. The above experimental results showed that Thz/PPM is an ideal and effective pH-responsive drug delivery carrier to a targeted therapy of CSCs.Keywords:poly(β-amino ester);polymeric micelles;pH-responsive;cancer stem cells;thioridazine
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高影响因子
MOLECULES
·
2025
·Vol. 31
·期 1
·133
·
IF 4.6
Yuancai Lv,Xuepeng Lin,Kai Yang,Yifan Liu,Xiaoxia Ye,Liang Song,Chunxiang Lin,Guifang Yang,Minghua Liu
Depolymerizing lignin to produce high-value chemicals has garnered increasing attention. Given the complex structure of real lignin, the cracking efficiency ofβ-O-4 linkages and the selectivity of depolymerization products are significantly lower than those of lignin model compounds. Meanwhile, the relationship between the structure of lignin and theβ-O-4 linkage cracking was ignored. In this work, to well address the issue, three real lignins (corncob lignin (CL), pinus massoniana lignin (PML), and eucalyptus lignin (EL)) were employed to discuss the impacts of special ether bonds in lignin on theβ-O-4 linkage cracking in the no-additional-hydrogen catalytic system mediated by a CoNi2@BTC catalyst. The lignin depolymerization results showed that the ether bonding structure in the lignin significantly impacted the cracking ofβ-O-4 linkages and selectivity of the final products, resulting in a great difference among their intermediates. Notably, the methoxy groups in the real lignin greatly inhibited the further hydrogenation of phenolic compounds, resulting in the accumulation of abundant methoxy-substituted phenolic compounds and a low yield of cycloalkanes (12.37% to 14.06%). To deeply discuss theβ-O-4 linkage cracking in the lignin depolymerization, degradation experiments with coexisting ether bond compounds were performed, and the activation energy was employed to quantitatively evaluate the impacts of other ether bonds on theβ-O-4 linkage cracking. The results revealed that multiple ether bonds (α-O-4, 4-O-5, and methoxy group) significantly increased the activation energy (from 236% to 373%) ofβ-O-4 linkages, resulting in the evident decline in theβ-O-4 model compound. In addition, the degradation of the methoxy-substitutedβ-O-4 model compound (GG) demonstrated that the methoxy-substituted aromatic ring products were resistant to further hydrogenation, resulting in the accumulation of methoxy-substituted aromatic ring products in the depolymerization of real lignin. All the findings will provide a novel perspective for the targeted high-value utilization of real lignin in chemical production.
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2017
·
IF 4.747
Yinxiu Rong,Naiyu Xu,Bingying Xie,Jie Hao,Lin Yi,Ruomei Cheng,Duxin Li,Robert J. Linhardt,Zhenqing Zhang
Highland barley is one of the hull-less barleys that contains high amounts of β-glucan. A detailed sequence analysis is needed to support the application of the β-glucan from highland barley. The β-conformation and 1 → 3/1 → 4 linkages were confirmed using nuclear magnetic resonance (NMR) spectroscopy. Monosaccharide analysis was accomplished with high-performance anion exchange chromatography (HPAEC) coupled to pulsed amperometric detection (PAD) and showed that glucose (G) was the dominant sugar component of this β-glucan. HPAEC-PAD was applied with on-line electrospray ion - to quadrupole time – of – flight mass spectrometry (Q/TOF-MS) to sequence oligosaccharides enzymatically derived from this β-glucan. More than 20 oligosaccharides were observed in the partially digested β-glucan mixture and their degree of polymerization (dp), confirmed by MS analysis, ranged from dp 2 to dp 20. The sequences of oligosaccharide dp2 – dp7 in the digested product mixture were unambiguously determined with MS/MS. Based on the sequence analysis of these oligosaccharides, G1→3G1→4G and G1→3G1→4G1→4G were determined to be the major repeating blocks of this β-glucan, and they were interspersed with homogeneous 1 → 4 linked domains with different lengths. The ratio of 1 → 3 and 1 → 4 linkages in the β-glucan was approximately 1:3.
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高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Qiaolei Li,Yanni Huang,Yaliyi Du,You Chen,Yanping Wu,Kai Zhong,Yina Huang,Hong Gao
The beneficial effects of olive oil consumption make it be one of the leading healthy edible oils worldwide. However, the water insolubility and oxidation of olive oil hinder its applications. In this study, food-grade oil-in-water olive oil Pickering emulsions (OOPEs) stabilized by hybrid starch/β-cyclodextrin nanoparticles (starch/β-CD NPs) was developed and characterized. The starch/β-CD NPs concentration and oil phase fraction had a significant influence on the droplet size, zeta potential and storage stability of emulsions. Confocal laser scanning microscopic observation revealed that the starch/β-CD NPs mainly located at the interface of oil droplets, forming a network structure to stabilize emulsions. Rheological analysis indicated the shear-thinning behavior and gel-like structure of starch/β-CD NPs stabilized OOPEs. Additionally, the obtained OOPEs remarkably improved the oxidative stability and storage stability by inhibiting the lipid oxidation compared to pure olive oil. Furthermore, animal experiments indicated that OOPEs modulated the gut microbiota in mice with an enhanced richness and diversity, resulting in an increased abundance of health-promoting bacteria. Notably, high-dosage OOPEs significantly decreased the ratio of phyla Firmicutes/Bacteroidetes. These findings could facilitate the development of olive oil Pickering emulsion with excellent stability and health effects on gut microbiota for applications in foods.
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高影响因子
Food & Function
·
2022
·Vol. 13
·期 23
·12330-12341
·
IF 6.317
Huiying Kuang,Yu Ma,Yixiang Liu
β-Carotene is a dietary source of vitamin A, and its physiological functions, such as anti-inflammatory activity, immune regulation, and improvement of intestinal flora, are attracting increasing attention. Recent studies have shown that the development of food allergy is closely related to intestinal dysfunction. Therefore, the present study investigated the potential anti-food allergy activity of β-carotene and its regulatory intestinal homeostasis pathway. The results obtained using an ovalbumin (OVA)-induced food allergy mouse model indicated that the clinical allergic symptoms were alleviated, and the levels of anaphylactic mediators (such as immunoglobulin (Ig) E, IgG, and histamine) were reduced after β-carotene supplementation at 5.00 mg per kg per day. In addition, the expression of tight junction (TJ) proteins (claudin-1, occludin, and ZO-1) increased by 38.58%, 24.39%, and 26.23%, respectively. Additionally, the secretion of secretory IgA (sIgA) and the regeneration of islet-derived protein (Reg) IIIγ were promoted in the intestinal mucous after β-carotene administration. Furthermore, the alpha and beta diversity analysis showed that the composition and diversity of the intestinal flora in the β-carotene group tended to be normalized compared to the model group. Higher levels of beneficial bacteria, such as Clostridiaceae, were evident in the intestinal microflora of the sensitized mice after β-carotene administration, while pathogenic bacteria, such as Streptococcaceae, were reduced. Consequently, β-carotene may protect against food allergy by strengthening intestinal epithelial barrier function and regulating intestinal microflora.
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PubMed
高影响因子
Materials Research Express
·
2022
·Vol. 9
·期 2
·025305
·
IF 2.025
Long-juan Ma,Yi-heng Lu,Yan Chen,Yu-wei Lu,Gang Yuan
Understanding the influence of additives on the dehydrochlorination of plasticized poly(vinyl chloride) (PVC) from the source and long-term storage is an attractive topic. In this work, the effects of folic acid modified nano titanium dioxide (FANT), cerium stearate, organotin and β -diketone compound additives on the dehydrochlorination of plasticized PVC and long-term storage were investigated using conductivity measurements. The results showed that the induction time of hydrogen chloride removal of plasticized PVC (C-1) containing composite stabilizer at 200 °C were 243% higher than those of the control (S1). After storage, the heat stability of the control decreased significantly. Instead, the induction time and stability time of plasticized PVC containing FANT, cerium stearate, organotin and β- diketone composites were significantly enhanced at 200 °C. The thermal stability sequence from difficult to easy for removal of hydrogen chloride was : 3.0 phr (1.90% wt) (C2) >1.0 phr (0.64% wt) (C1) > 5.0 phr (3.17% wt) (C3) with FANT. It is inferred that this is due to the FANT's hydrogen bonding van der Waals force and the complexation reaction of variable valence metal Ce+3/Ce+4 with C-Cl bond in PVC polymer molecule. The induction time (min) of hydrogen chloride removal at 200 °C before and after storage is as follows: C-20 (71.9) > C-10 (70.6) > C-1 (60.7) > C-3 (57.2) > C-30 (52.7) > C-2 (49.9) > S1 (25.3) > S10 (19.7). The critical temperature for hydrogen chloride removal by the composite film is around 210 °C. If the content of FANT increased to 3.17%, the intermolecular force and repulsive force in PVC system offset each other, indicating that the increase of FANT content will lead to the increase of repulsive force with PVC. A certain amount of FANT, cerium stearate, organotin and β- diketone composites has a significant synergistic effect on the thermal stability of PVC.
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高影响因子
INORGANICA CHIMICA ACTA
·
2024
·
IF 2.7
Shi-Jie Xian,Tao Sun,Yan Li,Kai Wang
Six ternary lanthanide complexes with different β-diketones as primary “antenna” ligand and 2,2’:6’,2’’-terpyridine as neutral ancillary ligand, namely [Ln(hfac) 3 (tpy)] [Ln(III) = Eu ( 1 ), Gd ( 2 ), Tb ( 3 ); hfac = hexafluoroacetylacetone; tpy = 2,2’:6’,2’’-terpyridine] and [Ln(btfa) 3 (tpy)] [Ln(III) = Eu ( 4 ), Gd ( 5 ), Tb ( 6 ); btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione], were synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, single crystal X-ray diffraction and powder X-ray diffraction. The three-dimensional Hirshfeld surface map and two-dimensional fingerprint analysis reveal that the substitution of hfac with btfa result in the decrease of the H···F/F···H and F···F interactions and the increase of the C···H/H···C and H···H interactions. Solid-state luminescence investigations indicate that the Eu(III) complexes ( 1 -Eu and 4 -Eu) and the Tb(III) complexes ( 3 -Tb and 6 -Tb ) display the characteristic lanthanide-centered luminescence upon UV excitations. 1 -Eu and 4 -Eu emit red light at CIE: 0.6827, 0.3172 and CIE: 0.6819, 0.3179 with the quantum yields (QY) of 78.70 % and 68.85 % and the lifetimes ( τ ) of 0.768 and 0.808 ms, respectively. 3-Tb and 6-Tb emit green light at CIE: 0.2677, 0.7221 and CIE: 0.2680, 0.7217 with the QY values of 7.56 % and 1.38 % and the τ values of 0.076 and 0.022 ms, respectively. For the Eu(III) complexes, the substitution of hfac by btfa makes the QY value lower from 78.70 % to 68.85 % and slightly prolong the τ value from 0.768 to 0.808 ms, while for the Tb(III) complexes, both of the QY and τ values decrease. The results suggest that the structures of the primary β-diketone ligands could affect the luminescence performances such as QY and τ values of the Eu(III) and Tb(III) complexes.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yuan-Yuan Cui,Yan-Ping Bi,Cheng-Xiong Yang
Layer-stacking structures via the template-free synthesis are rare in two-dimensional microporous organic networks (2D MONs). Herein, we report a facile solvent regulation and template-free strategy by tuning the aggregation degree of 2D β-cyclodextrin (CD)-based MONs nanosheets. The 2D MON nanosheets provided larger uptake capacity and faster kinetics than the aggregated CD-MONs, revealing the significance of morphology control for the removal of pollutants. The prepared 2D CD-MON-DMF gave ultrafast adsorption kinetics and exhibited much larger saturation sorption capacity (327.9 mg g −1 ) than previous adsorbents for bisphenol AF. The developed strategy not only provides a novel way to construct 2D MON nanosheets for highly efficient removal of organic pollutants from water but also promotes the utilization of MONs in material and environmental sciences.
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高影响因子
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2024
·
IF 6
Haolan You,Yihe Song,Yi Yang,Xicheng Wang,Shiqi Pan,Junyang Huang,Qiqi Shao,Donglei Shi,Baoli Li,Jian Li,Xiaokang Li
Beta-amyloid (Aβ), the most pivotal pathological hallmark for Alzheimer's disease (AD) diagnosis and drug evaluation, was recognized by TZ095 , a high-affinity fluorescent probe developed by rational molecular design. With a TICT mechanism, TZ095 exhibited remarkable affinity with Aβ aggregates (K d = 81.54 nM for oligomers; K d = 66.70 nM for fibril) and substantial fluorescence enhancement (F/F 0 = 44), enabling real-time monitoring of Aβ in live cells and nematodes. Significantly, this work used TZ095 to construct a new protocol that can quickly and conveniently monitor Aβ changes at the cellular and nematode levels to evaluate the anti-AD efficacy of candidate compounds, and four reported Aβ-lowering drug candidates were administrated for validation. Imaging data demonstrated that TZ095 can visually and quantitatively track the effect of Aβ elimination after drug treatment. Furthermore, TZ095 excelled in ex vivo histological staining of 12-month-old APP/PS1 mouse brains, accurately visualizing Aβ plaques. Integrating CUBIC technology, TZ095 facilitated whole-brain, 3D imaging of Aβ distribution in APP/PS1 mice, enabling high-resolution in situ analysis of Aβ plaques. Collectively, these innovative applications of TZ095 offer a promising strategy for rapid, convenient, and real-time monitoring of Aβ levels in preclinical therapeutic assessments.
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高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
·
2024
·
IF 2.3
Bingru Zheng,Jinjie Chen,Yizhou Xu,Wanrui Wu,Yu Zhu,Wei Cai,Weili Lin,Changsheng Shi
Introduction: Deep vein thrombosis (DVT) is a major cause of cardiovascular disease-related deaths worldwide and is considered a thrombotic inflammatory disorder. IL-1β, as a key promoter of venous thrombus inflammation, is a potential target for DVT treatment. Constructing a nanocarrier system for intracellular delivery of siIL-1β to silence IL-1β may be an effective strategy for alleviating DVT. Methods: ELISA was used to detect the expression levels of IL-1β and t-PA in the serum of DVT patients and healthy individuals. In vitro, HUVEC cells were treated with IL-1β, and changes in VWF and t-PA expression levels were assessed. PBAE/MCM-41@siIL-1β (PM@siIL-1β) nano-complexes were synthesized, the characterization and biocompatibility of PM@siIL-1β were evaluated. A rat hind limb DVT model was established, and PM@siIL-1β was used to treat DVT rats. Morphology of the inferior vena cava, endothelial cell count, IL-1β, vWF, and t-PA levels, as well as changes in the p38 MAPK and NF-κB pathways, were examined in the different groups. Results: IL-1β and t-PA were highly expressed in DVT patients, and IL-1β treatment induced a decrease in VWF levels and an increase in t-PA levels in HUVEC cells. The synthesized PM@siIL-1β exhibited spherical shape, good stability, high encapsulation efficiency, and high drug loading capacity, with excellent biocompatibility. In the DVT model rats, the inferior vena cava was filled with blood clots, endothelial cells increased, IL-1β and VWF levels significantly increased, while t-PA levels were significantly downregulated. Treatment with PM@siIL-1β resulted in reduced thrombus formation, decreased endothelial cell count, and reversal of IL-1β, VWF, and t-PA levels. Furthermore, PM@siIL-1β treatment significantly inhibited p38 phosphorylation and upregulation of NF-κB expression in the DVT model group. Conclusion: IL-1β can be considered a therapeutic target for suppressing DVT inflammation. The synthesized PM@siIL-1β achieved efficient delivery and gene silencing of siIL-1β, demonstrating good therapeutic effects on rat hind limb DVT, including anti-thrombotic and anti-inflammatory effects, potentially mediated through the p38 MAPK and NF-κB pathways.
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Yunchao Zheng,Meijun Wan,Jingqiu Zhou,Xuemei Dai,Honglin Yang,Zhining Xia,Lujun Wang
As a welcomed porous material, covalent organic frameworks (COFs) have many advantages and are widely used in various aspects. Particularly, COFs have aroused great attentions of scientists in chromatographic separation field due to their outstanding advantages, such as high stability, large specific surface area and multiple voids. However, endowing COFs with chirality to construct chiral stationary phase (CSP) function is still facing many challenges. Here, we firstly prepared a β -cyclodextrin ( β -CD) and covalent organic framework functional silica CSP named as COF@CD@SiO 2 by one-pot method to perform high performance liquid chromatography (HPLC) chiral separation . The morphology and structure of the synthesized stationary phase were investigated by a variety of characterization methods including Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), N 2 adsorption experiment, powder X-ray diffraction (XRD) and elemental analysis (EA). The prepared stationary phase realized fast separation of six enantiomers in a short time. The separation mechanism was mainly ascribed to the inclusion complexation of β -cyclodextrin and the mutli-interaction sites from COFs material. In conclusion, the prepared chiral column can be used to achieve fast separation of enantiomers with good stability and reproducibility. These results can open new avenue for using chiral COFs in liquid chromatographic separation .
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高影响因子
危险品化学品经营许可证（带存储）