CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2023
·
IF 3.8
Renwen Tian,Yan Sun
Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. A recently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potential for degrading PET at moderate temperatures, but its activity and stability need further improvement for practical applications. Herein, we proposed to use α-synuclein (αS) as a fusion chaperone and created six PETase-αS fusion enzymes with linkers of different types and lengths. All the fusion enzymes exhibited improved enzymatic performance, presenting 1.5 to 2.6-fold higher activity towards bis-2(hydroxyethyl) terephthalate than PETase, as well as significantly increased stabilities. Fluorescence spectroscopy indicated that the chaperone fusion tightened the overall conformation and resulted in the opening of the substrate binding pocket, which led to the improved thermal stability and catalytic activity of the fusion enzymes. Remarkably, one of the fusion proteins, PETase-[(GS)(EK)] 10 -αS, showed 3.2 to 5.1 times higher PET degradation capability than PETase. The significantly boosted PET degradation performance was not only attributed to the enhanced enzymatic activity and stability, but also possibly due to the binding affinity of the fused αS domain for PET. These findings demonstrated that αS was an effective fusion chaperone for significantly enhancing the enzymatic performance of PETase.
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Marine Drugs
·
2023
·Vol. 21
·期 5
·286
·
IF 5.4
Jianying Dong,Panpan Zhang,Junjie Xie,Ting Xie,Xiaopeng Zhu,Dongting Zhangsun,Jinpeng Yu,Sulan Luo
α4/6-conotoxin TxID, which was identified fromConus textile, simultaneously blocks rat (r) α3β4 and rα6/α3β4 nicotinic acetylcholine receptors (nAChRs) with IC50values of 3.6 nM and 33.9 nM, respectively. In order to identify the effects of loop2 size on the potency of TxID, alanine (Ala) insertion and truncation mutants were designed and synthesized in this study. An electrophysiological assay was used to evaluate the activity of TxID and its loop2-modified mutants. The results showed that the inhibition of 4/7-subfamily mutants [+9A]TxID, [+10A]TxID, [+14A]TxID, and all the 4/5-subfamily mutants against rα3β4 and rα6/α3β4 nAChRs decreased. Overall, ala-insertion or truncation of the 9th, 10th, and 11th amino acid results in a loss of inhibition and the truncation of loop2 has more obvious impacts on its functions. Our findings have strengthened the understanding of α-conotoxin, provided guidance for further modifications, and offered a perspective for future studies on the molecular mechanism of the interaction between α-conotoxins and nAChRs.Keywords:α-conotoxin TxID;α3β4 nAChR;loop size modification;electrophysiology;CD spectra
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PubMed
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Molecular Catalysis
·
2022
·
IF 5.089
Changhui Zhu,Kaiqiang Wang,Jia Luo,Baohe Tian,Jialin Sun,Xinhong Liu,Wenchao Zhu,Zhiyun Zou
α -Aromatic amino acid esters are important platform compound for drugs, sweeteners and fluorescent sensors. Due to the amphoteric dissociation and steric effect, the esterification of α -aromatic amino acids is difficult. Here, a green and efficient solid superacid, SO 4 2− -S 2 O 8 2− /SnO 2 -Nd 2 O 3 (SSSN), was synthesized and firstly used for the methyl esterification of α -aromatic L-tyrosine and L-tryptophan. The methyl esters yield was optimized with the highest L-TyrOMe yield of 93.1% and L-TrpOMe yield of 92% over SSSN-650 (SO 4 2− -S 2 O 8 2− /SnO 2 -Nd 2 O 3 calcined under 650 °C). Furthermore, it was clarified that the doping of Nd enhanced the electron-withdrawing inductive effect of SO 4 2− /S 2 O 8 2− with increased Brønsted and Lewis acidity, which were beneficial to the esterification of L-tyrosine and L-tryptophan. Besides, Nd-doping reduced the activation energy during L-Tyr esterification by kinetics study. Finally, SSSN-650 could be recycled six times with > 70% of their initial ester yield. The decrease of catalyst activity was caused by carbon deposition and species leaching. This work launched a novelty, rapid and environmental-benign technology for the esterification of α -aromatic amino acid using solid superacid.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Caiyun Cheng,Chao Yuan,Bo Cui,Jianpeng Li,Guimei Liu
β-Cyclodextrin (β-CD) Pickering emulsion and cinnamaldehyde/β-cyclodextrin (CIN/β-CD) Pickering emulsion were prepared and the influences of oxidation and digestion were investigated. CIN/β-CD composite was better dispersed at the oil–water interface than β-CD. Hydrophobic group of CIN anchored in the oil phase and Hydrophilic hydroxyl group of β-CD extended into the aqueous phase, which allowed CIN/β-CD composite to be oriented at the oil–water interface and formed a more stable oil–water interface layer. β-CD Pickering emulsion was more susceptible to oxidative deterioration than CIN/β-CD Pickering emulsion, its malondialdehyde (MDA) value was as high as 509.41 ± 9.37 nmol/L. Digestion experiment indicated that CIN/β-CD Pickering emulsion was released inner oil phase in the small intestine and free fatty acid (FFA) release rate was 44.32 ± 1.08%. Pharmacokinetic parameters manifested that α-tocopherol peak concentration (C max ) was 64.32 ± 6.45 mg/L and the peak time (T max ) appeared at 5 h after administration of CIN/β-CD Pickering emulsion.
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Molecular Catalysis
·
2023
·
IF 4.6
Qinzhe Lin,Xuanjin Lv,Xianming Zeng,Mengning Zhong,Qiyun Wu,Huilin Ren,Shenpeng Xu,Wentian Chen,Wenting Du,Jun Li
The potential applications of imine reductases (IREDs) in chiral amine synthesis have garnered significant attention. However, there is still limited research on IRED for reacting with bulky substrates. In this study, we addressed this gap by mutating engineered IRED M5 when confronted with a bulky amine substrate, α-methylphenylethylamine. Our investigation revealed the relatively low catalytic efficiency of engineered IRED M5 when tasked with α-methylphenylethylamine. To enhance the catalytic performance of IRED M5, the mutants M203V and F260A were obtained by rational design. F260A exhibited a substantial improvement in the conversion of tert‑butyl 3-((( R )-1-phenylethyl)amino)piperidine-1-carboxylate, exceeding 2-fold. This enhancement suggests that the F260A mutation likely led to a more conducive active site or increased substrate binding affinity. Furthermore, F260A demonstrated a significant enhancement in stereoselectivity when applied to tert‑butyl 4-((( S )-1-phenylethyl)amino)azepane-1-carboxylate, with the enantiomeric excess ( e.e. ) increasing from 9% to 86% ( S ). M203V increased conversions for 3-((( R / S )-1-phenylethyl)amino)piperidine-1-carboxylate. In addition, we revealed a possible the underlying molecular mechanism of the effect of F260A and M203V on catalytic performance. Our study provides a deeper understanding of the rational design according to the interaction between IRED cavity and substrate.
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高影响因子
MOLECULES
·
2023
·Vol. 28
·期 24
·7956
·
IF 4.6
Qu-Jing Luo,Wen-Chao Zhou,Xin-Yi Liu,Ya-Jie Li,Qing-Ling Xie,Bin Wang,Chao Liu,Wen-Mao Wang,Wei Wang,Xu-Dong Zhou
Ampelopsis grossedentatais a valuable medicinal and edible plant, which is often used as a traditional tea by the Tujia people in China.A. grossedentatahas numerous biological activities and is now widely used in the pharmaceutical and food industries. In this study, two new flavonoids (1–2) and seventeen known compounds (3–19) were isolated and identified from the dried stems and leaves ofA. grossedentata. These isolated compounds were characterized by various spectroscopic data including mass spectrometry and nuclear magnetic resonance spectroscopy. All isolates were assessed for their α-glucosidase inhibitory, antioxidant, and hepatoprotective activities, and their structure–activity relationships were further discussed. The results indicated that compound1exhibited effective inhibitory activity against α-glucosidase, with an IC50value of 0.21 μM. In addition, compounds1–2demonstrated not only potent antioxidant activities but also superior hepatoprotective properties. The findings of this study could serve as a reference for the development ofA. grossedentata-derivedproducts or drugs aimed at realizing their antidiabetic, antioxidant, and hepatoprotective functions.Keywords:Ampelopsis;Ampelopsis grossedentata;flavonoids;α-glucosidase inhibitory;antioxidant;hepatoprotective activity
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PubMed
高影响因子
ACS Catalysis
·
2023
·
IF 12.9
Luyao Guo,Xiaoyan Liu,Ziang Zhao,Ronghe Lin,Yu Meng,Xinzheng Ma,Yihui Li,Xiaoling Mou,Li Yan,Hejun Zhu,Yunjie Ding
Nanostructured bimetallic Pt–Bi catalysts are designed by defect engineering of N-doped carbons as the hosts. The optimal catalyst delivers good yields (>98%) in the direct oxidation of C5–C9 linear α-alcohols to corresponding fatty acids, significantly outperforming activated carbon-supported benchmarks and rivaling the state-of-the-art systems. A combined kinetic and computational study on n-heptanol oxidation as a model reaction unveils the kinetic and thermodynamic origins of the better performance of the PtBi alloy than neat or Bi-modified Pt(111) surfaces. Structure–performance correlations further identify that the metal particle size, surface Bi/Pt ratio, and strong basicity strongly influence the catalyst performance in alcohol oxidation. The creation of nitrogen defects facilitates the formation of the surface PtBi alloy and brings strong basicity, accounting for the boosted performance. These findings enable a step closer toward the manufacture of valuable fatty acids from abundant coal by coupling the advanced oxidation with the recently piloted higher alcohol synthesis via the Co–Co2C-catalyzed Fischer–Tropsch reaction.
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MATERIALS RESEARCH INNOVATIONS
·
2015
·
IF 0.83
D. H. He,A. P. Tang,Q. W. Zhong,Z. Q. He,G. R. Xu,H. S. Song
Porous α-LiVOPO4/C composite was prepared by the solution combustion synthesis method followed by annealing at 500°C for a short annealing duration of just 50 min. The synthesised material was characterised by XRD, SEM, TEM, N2 adsorption–desorption isotherms and charge–discharge tests. When tested at 0.05C rate for Li ion insertion properties, α-LiVOPO4/C composite exhibits good cycle capability with an negligible capacity degradation for the first 31 cycles. However, it shows poor rate capability with initial discharge specific capacities of 127.6 mAh g− 1 (0.05C), 109.1 mAh g− 1 (0.1C) and 74.9 mAh g− 1 (0.2C), respectively.
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Journal of Coatings Technology and Research
·
2021
·Vol. 18
·期 4
·999-1012
·
IF 2.382
Situ Yue,Guo Yanlin,Ji Weiwei,Liu Defei,Wei Dan,Huang Hong
Polyaniline (PANI) encapsulated α-zirconium phosphate (α-ZrP) nanocomposites (PANI/α-ZrP) were prepared by in situ oxidative polymerization and used as anticorrosive filler in epoxy coatings. Water absorption test and electrochemical measurements in 3.5 wt.% NaCl solution were conducted to assess the barrier properties and anticorrosion performances of different coating systems. PANI/α-ZrP composite epoxy coating showed remarkably enhanced corrosion resistance comparing to neat epoxy coating because of “maze effect” from α-ZrP and “passivation effect” from PANI. The α-ZrP nanosheets could be completely encapsulated by PANI with appropriate PANI/α-ZrP mass ratio, and the resulting nanocomposite exhibited optimal corrosion protection properties.
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Advanced Materials Interfaces
·
2020
·Vol. 8
·期 5
·2001831
·
IF 4.948
Peng Wang,Su-Zhen Wang,Qing Han,Dong-Qinq Zou,Wen-Kai Zhao,Xue-Dong Wang,Chen Luo,Xin Yang,Xing Wu,Wan-Feng Xie
Gas sensors based on SnO 2 , Fe 2 O 3 , and their nanocomposites are promising candidates for sensing of acetone, ethanol, hydrogen, NO 2 , ozone, and formaldehyde. In this work, a rational hydrothermal route is designed to prepare α-Fe 2 O 3 /SnO 2 porous sphere arrays assembled with hierarchical nanostructure (denoted as α-Fe 2 O 3 ( x %)/SnO 2 ). The results demonstrate that the α-Fe 2 O 3 (4%)/SnO 2 based sensor exhibits excellent sensing performance, the short response/recovery time of 3 and 4 s, respectively. A very low working temperature of 200 °C, wide linear detection range (from 500 ppb to 500 ppm), and long-term cycling stability of as long as 90 days, and stable performance at 80% of relative humidity. The sensing signals can be accurately sampled and processed by the integrated circuit system, to collect and monitor the acetone concentration alteration signals in real time. Furthermore, the gas sensing performance is interpreted by the functions of hierarchical nanostructure and synergistic effect of Fe 2 O 3 /SnO 2 nanohybrids.
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高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Hui Mei,Shixiang Zhou,Mingyang Lu,Yong Zhao,Laifei Cheng
For real-time environmental monitoring and gas detection under harsh conditions, gas sensors with high reliability, sensitivity, and selectivity are in increasing demand. Therefore, pine-branch-like α-Fe 2 O 3 /TiO 2 with a core–shell hierarchical heterojunction structure was designed and fabricated for ethanol sensing. The heterojunction increased the O adsorption, resulting in the formation of more chemisorbed O species for reaction with the target gas. Moreover, the pine-branch-like morphology formed three-dimensional hollow holes as channels for molecule diffusion and adsorption. Compared with gas-proof structures, the hollow regions can realize gas diffusion in the inner and outer surfaces of materials simultaneously. Further, in contrast to aggregated structures, the fibers were separated from each other, and charge conduction between the fibers needed to pass through the surface sensing layer at the fiber boundary; thus, the overall resistance change of the sensors was significantly affected by the response of the heterojunction to the target gas. Consequently, the α-Fe 2 O 3 /TiO 2 sensor exhibited a high response value of 40.4 toward 500 ppm ethanol gas and had excellent selectivity to ethanol. The proposed strategy may facilitate the design and construction of effective heterojunctions and nanostructures for gas sensing.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Li-Chao Wang,Lian Xu,Xin-Qi Xu,Bing-Mei Su,Juan Lin
L-threonine aldolase (LTA) is a PLP-dependent enzyme that can reversibly catalyze aldol reaction of glycine and acetaldehyde to produce β -hydroxy- α -amino acids. In the present work, a putative lta gene from Actinocorallia herbida (AhLTA) was mined and over-expressed in Escherichia coli BL21 (DE3). The substrate spectrum assay indicated that AhLTA only used glycine as donor substrate and tolerated a wild range of aromatic aldehydes as acceptor substrates. It was found that the type and position of substituents in the aromatic aldehydes exerted a significant impact on the activity and stereoselectivity at β -carbon of AhLTA. Among those substrates, AhLTA could catalyze glycine and 4-methylsulphonyl benzaldehyde ( 14a ) to produce L- threo -4-methylsulfonylphenylserine ((2 S ,3 R )- 14b ) with high conversion (94.4%) and moderate stereoselectivity (19% de ). By conditional optimization, the de value of (2 S , 3 R )- 14b was improved to 61% and the conversion was 75%. Taken together, our study suggested that AhLTA might be a promising catalyst for producing chiral β -hydroxy- α -amino acids.
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高影响因子
危险品化学品经营许可证（带存储）