Heliyon
·
2023
·Vol. 9
·期 9
·e19889
·
IF 4
Zhou Chen,Yimei Shen,Run Wang,Siting Li,Yingmin Jia
A novel gene ( BbFFase9 ), with an ORF of 1557 bp that encodes β-d-fructofuranosidase from Bifidobacteriaceae bacterium , was cloned and expressed in Escherichia coli . The recombinant protein (BbFFase9) was successfully purified and showed a single band with a molecular mass of 66.2 kDa. This was confirmed as a β-d-fructofuranosidase and exhibited a high specific activity of 209.2 U/mg. Although BbFFase9 was a soluble protein, it exhibited excellent tolerance to proteases such as pepsin, trypsin, acidic protease, neutral protease and Flavourzyme®, indicating its potential applicability in different fields. BbFFase9 exhibited typical invertase activity, and highly catalyzed the hydrolysis of the α1↔2β glycosidic linkage in molecules containing fructosyl moieties but with no detectable fructosyltransferase activity. It was optimally active at pH 6.5 and 50 °C and stable between pH 6.0 and 9.0 at a temperature of up to 45 °C for 30 min BbFFase9 could also effectively hydrolyze galacto-oligosaccharides, which are a flatulence factor in soybean meal, thus releasing new types of product such as melibiose and mannotriose, or degrading them into invert sugars, the sweeter fructose and glucose. This study is the first to report the application of this type of β-d-fructofuranosidase.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Jianrong Chen,Dengfeng Yang,Yunkai Zhang,Liyan Yang,Qingyan Wang,Mingguo Jiang,Lixia Pan
In order to better utilize chitinolytic enzymes to produce high-value N -acetyl-D-glucosamine (GlcNAc) from chitinous waste, there is an urgent need to explore bi-functional chitinases with exceptional properties of temperature, pH and metal tolerance. In this study, we cloned and characterized a novel bi-functional cold-adaptive chitinase called Ca Chi18A from a newly isolated strain, Chitinilyticum aquatile CSC-1, in Bama longevity village of Guangxi Province, China. The activity of Ca Chi18A at 50 °C was 4.07 U/mg. However, it exhibited significant catalytic activity even at 5 °C. Its truncated variant Ca Chi18A_ΔChBDs, containing only catalytic domain, demonstrated significant activity levels, exceeding 40 %, over a temperature range of 5–60 °C and a pH range of 3 to 10. It was noteworthy that it displayed tolerance towards most metal ions at a final concentration of 0.1 mM, including Fe 3+ and Cu 2+ ions, retaining 122.52 ± 0.17 % and 116.42 ± 1.52 % activity, respectively. Additionally, it exhibited favorable tolerance towards organic solvents with the exception of formic acid. Interestedly, Ca Chi18A and Ca Chi18A_ΔChBDs had a low K m value towards colloidal chitin (CC), 0.94 mg mL −1 and 2.13 mg mL −1 , respectively. Both enzymes exhibited chitobiosidase and N -acetyl-D-glucosaminidase activities, producing GlcNAc as the primary product when hydrolyzing CC. The high activities across a broader temperature and pH range, strong environmental adaptability, and hydrolytic properties of Ca Chi18A_ΔChBDs suggested that it could be a promising candidate for GlcNAc production.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Ling Ding,Shen Song,Lele Chen,Jipeng Shi,Baotang Zhao,Guixiang Teng,Ji Zhang
In this work, an innovative composite hydrogel composed of curdlan (CD)/polyvinyl alcohol (PVA) hydrogels with a 3-d network structure was successfully prepared by freeze-thaw processing. The presence of interactions, changes in crystallinity, and thermal behaviour were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetry (TGA and DTG), respectively. The morphology of the hydrogels was investigated by scanning electron microscopy (SEM). With the increase of PVA concentration, the composite hydrogel had a greater mechanical strength while remaining remarkably ductile as evinced by tensile test results. PVA content affects the swelling and water retention of CD/PVA hydrogels. The results of CCK-8 assay showed that CD/PVA hydrogels have no cytotoxic effect on the mouse fibroblast L929 cells. The AO/EB double-staining experiment further proved that the cells in the composite hydrogels had good cytocompatibility. The porous biohydrogels developed in the present work can provide an ideal cell growth environment as a scaffold. CD/PVA hydrogels highlight the value of this system for cell adhesion and proliferation, and further soft tissue engineering application.
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MOLECULES
·
2020
·Vol. 25
·期 22
·5391
·
IF 3.267
Zheng Liu,Ming Bian,Qian-Qian Ma,Zhuo Zhang,Huan-Huan Du,Cheng-Xi Wei
A series of novel synthetic substituted benzo[d]oxazole-based derivatives (5a–5v) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer’s disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ25-35-induced PC12 cells at 5 μg/mL. We found that compound5cwas non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ25-35-induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound5cpromoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ25-35-induced PC12 cells. In addition, our findings demonstrated that compound5cprotected PC12 cells from Aβ25-35-induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound5cshows less toxicity than donepezil in the heart and nervous system of zebrafish.Keywords:synthesis;benzo[d]oxazol;thiadiazoles;Alzheimer’s disease;β-amyloid;Akt/GSK-3β/NF-κB signaling pathway
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Food & Function
·
2020
·Vol. 11
·期 12
·10852-10863
·
IF 4.171
Mingbao Gu,Jie Jin,Chenghao Ren,Ximiao Chen,Weiyang Gao,Xiangyang Wang,Yaosen Wu,Naifeng Tian,Zongyou Pan,Aimin Wu,Yifei Zhou,Xiaolei Zhang
As an ordinary joint vestigial disease, osteoarthritis (OA) contributes to a considerable proportion of disability cases worldwide. Inflammation, as the main pathological factor, mediates the occurrence and development of OA. Akebia Saponin D (ASD), also known as Asperosaponin VI, is one of the active components extracted from Dipsaci Radix and is rich in Dipsacus loose tea. It has shown sound therapeutic effects on various diseases; nevertheless, its role in OA therapy is not completely understood. This study demonstrated the anti-inflammatory activity of ASD in OA through a series of in vivo and in vitro experiments. In vitro experiments revealed that ASD might prohibit the production of inflammatory mediators in IL-1β treated chondrocytes such as COX-2, iNOS, NO, PGE2, IL-6, and TNF-α. Meanwhile, it may also inhibit the production of ADAMTS-5 and MMP13 and promote the production of Aggrecan and Collagen II. The mechanism study demonstrated that ASD exerted an anti-inflammatory effect by activating the NRF2 target, upregulating the expression of HO-1, and preventing P65 from binding to DNA. In vivo experiments demonstrated that ASD might improve the progression of OA in a DMM mouse model. These research results provide evidence for the potential application of ASD in OA therapy.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 18
·50320
·
IF 2.52
Airong Xu,Fen Wang,Luwei Zhang,Xingmin Xu,Zhihong Xiao,Rukuan Liu
Polymer materials based on fossil resources have brought great convenience to various industries. However, environmental pollution is becoming increasingly conspicuous due to their difficult degradation in nature. Therefore, biodegradable composites are highly desired. In the present work, a simple and feasible preparation approach was presented to fabricate biodegradable and biocompatible composite films including methylcellulose/poly( d , l -lactide-co-glycolide) (MC/PLGA) and methylcellulose/poly(1,4-butylene succinate) (MC/PBS). The effects of MC/PLGA and MC/PBS mass ratios on the morphology, crystalline state, mechanical properties and thermal stability of the composite films were systematically investigated. At the same time, the influence of thermal compression treatment on mechanical properties (tensile strength and elongation) and the cyclic utilization of the composite films were also estimated. The composite films displayed enough good mechanical properties, re-usability and thermal stability.
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BIOORGANIC CHEMISTRY
·
2019
·
IF 3.926
Zhiyan Li,Zhenguo Zhang,Yanhong Chen,Shijun Tang,Tongyuan Lin,Jingfang Huang,Bo Li,Cheng Jiang
A series of d -amino acid-containing peptidomimetics were designed, synthesized as novel polo-like kinase 1 (Plk1) polo-box domain (PBD) inhibitors based on the reported peptide Plk1 PBD inhibitor. Their inhibitory activity to Plk1, Plk2, and Plk3 PBD were evaluated using our fluorescence polarization (FP) assay. Compound 18 bound to Plk1 PBD with IC 50 of 0.80 μM and showed nearly no inhibition to Plk2 PBD or Plk3 PBD at 100 μM. Compound 18 induced Hela cells to undergo apoptosis by increasing the ratio of the cells at the G2/M phase by decreasing the neosynthesized proteins in a dose-dependent manner from 50 to 150 μM. Compound 18 showed improved stability in rat plasma compared to l -peptide inhibitor LHSpTA. These novel d -amino acid modified selective Plk1 PBD inhibitors may provide new lead compounds for further optimization.
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DNA AND CELL BIOLOGY
·
2020
·Vol. 39
·期 3
·355-367
·
IF 3.314
Jiuwei Zhang,Yaodong Chen,Jing Lin,Ruimei Jia,Tingting An,Tianxiu Dong,Yu Zhang,Xiuhua Yang
Hepatocellular carcinoma (HCC), the sixth most common malignancy worldwide, is characterized by a dismal prognosis due to high recurrence and metastasis rates. Thus, the need for the development of novel chemotherapeutic drugs is urgent. Cyclovirobuxine D (CVB-D), a steroidal alkaloid extracted from Buxus microphylla that has been extensively used to relieve the symptoms of cardiovascular diseases, has shown promising antineoplastic effects in recent studies. However, the therapeutic effects and underlying mechanisms of CVB-D on HCC remain largely unelucidated. This study experimentally indicated that CVB-D can repress HCC cell proliferation by arresting the cell cycle in G2 phase and can facilitate apoptosis. In addition, the migratory and invasive capabilities of HCC cells were noticeably attenuated by a nonlethal dose of CVB-D, and this attenuation was correlated with the inhibition of epithelial–mesenchymal transition (EMT). Moreover, in vivo, CVB-D displayed excellent anticancer effects in HCC tumor-bearing nude mice. Regarding the molecular mechanisms of CVB-D activity, decreased Slug expression was determined to be associated with the aforementioned anti-HCC functions of this extract, which might be regulated by epidermal growth factor receptor (EGFR) through the focal adhesion kinase (FAK)-associated PI3K/AKT and MEK/ERK1/2 signaling pathways. Collectively, our results revealed the suppressive effects of CVB-D on progressive behaviors of HCC, including proliferation, migration, invasion, and EMT, in addition to its outstanding proapoptotic effects, which were correlated with the inhibition of the EGFR-FAK-AKT/ERK1/2-Slug signaling pathway. These discoveries provide an experimental and theoretical foundation for the use of CVB-D as a promising candidate for HCC therapy.
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FOOD AND CHEMICAL TOXICOLOGY
·
2020
·
IF 4.679
Desen Yang,Wanqin Wu,Guoping Gan,Dingkun Wang,Jing Gong,Ke Fang,Fuer Lu
The neuroprotective effects and potential mechanisms of (-)-Syringaresinol-4-O-β-D-glucopyranoside (SRG), a natural lignan glycoside extracted from Cortex Albizziae , were investigated using corticosterone (CORT)-induced PC12 cells as an in vitro anxiety model. PC12 cells were treated with 100 μM CORT and 5, 10, or 20 μM SRG for 48 h. Cell viability and lactate dehydrogenase (LDH) leakage were measured. Apoptosis were detected using FITC-coupled Annexin V (AV) and propidium iodide (PI) staining flow cytometric analyses and TUNEL assays. Rhodamine 123 and Fluo-3-AM staining flow cytometric analyses were used to detect mitochondrial membrane potential (ΔΨm) and intracellular calcium concentration ([Ca 2+ ] i ), respectively. Western blot was used to detect brain-derived neurotrophic factor (BDNF), Bax, Bcl-2, cAMP-response element binding protein (CREB), cytosolic cytochrome c (Cyt c ), caspase-3, and cleaved caspase-3. Experimental data showed that SRG promoted cell proliferation , reduced LDH release, inhibited apoptosis, improved ΔΨm values, decreased [Ca 2+ ] i , up-regulated CREB, BDNF, and Bcl-2, down-regulated Bax and Cyt c protein expression levels, and reduced caspase-3 activity. This suggests that SRG has neuroprotective and antiapoptotic effects in the pathogenesis of anxiety disorders, and its mechanisms are partly connecte to inhibition of the mitochondrial apoptotic pathway and activation of pathways involving CREB and BDNF.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Congshu Feng,Yun Chen,Jun Shao,Haoqing Hou
Blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) would produce polylactide stereocomplex crystallites (PLA SC). In the PLLA/PDLA specimens prepared by solution mixing or melt blending, the isomeric polymers were mixed in the molecular level. When the distance of these isomers increased, the crystallization behaviors of PLLA/PDLA were not clear yet. In this study, PLLA/PDLA blends were prepared by different electrospinning methods, i.e., spinning by mixed solution (DL-A), side-by-side mode (DL-B), and double spinnerets (DL-C). Results revealed that the distances between isomeric molecules increased in the order of DL-A, DL-B, and DL-C, and this distance influences the phase transition and subsequently crystallization behaviors. In the DL-A, the homochiral crystallites (HC) developed at first, and then SC formed in the specimen with lower content of PDLA. The formation of SC was observed at first, and less or no content of HC was developed with higher content of PDLA. For the DL-B group, the formation of HC was observed at ∼100 °C, and the SC were produced around 140 °C irrespective of composition. More content of SC was produced during or after melting of HC. When referring to the DL-C group, the HC developed at the first stage, and the SC were produced during or after melting of PLA HC. In addition, the SC that developed in the three groups have different nucleation efficiencies for the subsequent formation of HC. The nucleation efficiency increased in the order of DL-A < DL-B < DL-C, and these results hinted that not only the content but also the distribution of SC affects the formation of HC.
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GOLD BULLETIN
·
2020
·Vol. 53
·期 2
·55-62
·
IF 1.706
Li Degui,Luo Yujia,Lan Jiaxin,Luo Zhihong,Li Fujie,Luo Kun
Ligand exchange was triggered at toluene/water emulsion interface between homogeneous gold nanoparticles (Au NPs) with triphenylphosphine (PPh 3 ) and D-penicillamine (D-PA), resulted in amphiphilic Janus Au NPs with both phosphine and thiolate ligands. TEM and XRD analyses indicate that the product is composed of Au nanocrystals in an average diameter of about 3.7 nm. XPS, FTIR, Raman, and 1 H NMR analyses demonstrate that the Au NPs are protected with hydrophilic D-PA molecules and lipophilic PPh 3 ligands in a molecular ratio of ca. 1.8. The NOESY analysis and contact angle measurement further suggest that the D-PA and PPh 3 molecules are spontaneously separated to form compartmentalized hydrophilic and lipophilic regions on the individual Au NPs, which exhibit good catalytic performance and recyclability on the reduction of 4-nitrophenol. The results demonstrate that amphiphilic Janus Au NPs can be synthesized by partly exchange of PPh 3 with D-PA at toluene/water emulsion interface and are potentially applicable for other phosphine/thiolate pairs to modify Au NPs.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Rongkang Hu,Ruiguo Cui,Qingyun Tang,Dongming Lan,Fanghua Wang,Yonghua Wang
The mechanism of active site loops of Streptomyces phospholipase D (PLD) binding to the lipid–water interface for catalytic reactions still remains elusive. A flexible loop (residues 376–382) in the active site of Streptomyces klenkii PLD (SkPLD) is conserved within PLDs in most of the Streptomyces species. The residue Ser380 was found to be essential for the enzyme’s adsorption to the interface and its substrate recognition. The S380V mutant showed a 4.8 times higher catalytic efficiency and nearly seven times higher adsorption equilibrium coefficient compared to the wild-type SkPLD. The monolayer film technique has confirmed that the substitution of Ser380 with valine in the loop exhibited positive interaction between the enzyme and PCs with different acyl chain lengths. The results of the interfacial binding properties indicated that the S380V mutant might display suitable phosphatidylserine synthesis activity. The present study will be helpful to explain the role of residue 380 in the active site loops of Streptomyces PLD.
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