APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 195
·期 1
·298-313
·
IF 3.094
Liu Yani,Wei Fengdan,Xu Rui,Cheng Tao,Ma Yanling
Microbial remediation has become one of the promising ways to eliminate polycyclic aromatic hydrocarbons (PAHs) pollution due to its efficient enzyme metabolism system. Catechol 1,2-dioxygenase (C12O) is a crucial rate-limiting enzyme in the degradation pathway of PAHs in Achromobacter xylosoxidans DN002 that opens the benzene ring through the ortho-cleavage pathway. However, little attention has been given to explore the interaction mechanism of relevant enzyme–substrate. This study aims to investigate the binding interaction between C12O of strain DN002 and catechol by means of a molecular biological approach combined with homology modeling, molecular docking, and multiple spectroscopies. The removal rate of catechol in the mutant strain of cat A deletion was only 12.03%, compared to the wild-type strain (54.21%). A Ramachandran plot of active site regions of the primary amino acid sequences in the native enzyme showed that 93.5% sequences were in the most favored regions on account of the results of homology modeling, while an additional 6.2% amino acid sequences were found in conditionally allowed regions, and 0.4% in generously allowed regions. The binding pocket of C12O with catechol was analyzed to obtain that the catalytic trimeric group of Tyr164-His224-His226 was proven to be great vital for the ring-opening reaction of catechol by molecular docking. In the native enzyme, binding complexes were spontaneously formed by hydrophobic interactions. Binding constants and thermodynamic potentials from fluorescence spectra indicated that catechol effectively quenched the intrinsic fluorescence of C12O in the C12O/catechol complex via conventional static and dynamic quenching mechanisms of C12O. The results of ultraviolet and visible (UV) spectra, synchronous fluorescence, and circular dichroism (CD) spectra revealed conspicuous changes in the local conformation, and site-directed mutagenesis confirmed the role of predicted key residues during catalysis, wherein His 226 had a significant effect on catechol utilization by C12O. This is the first report to reveal interactions of C12O with substrate from the molecular docking results, providing the mechanistic understanding of representative dioxygenases involved in aromatic compound degradation, and a solid foundation for further site modifications as well as strategies for the directed evolution of this enzyme.
研究领域:
微生物学
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环境科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
POLYCYCLIC AROMATIC COMPOUNDS
·
2016
·
IF 0.959
Hongyun Nie,Maiqian Nie,Yongzhe Yang,Jing Zhao,Xinyi Zhang,Yutao Guo,Yi Wan,Jing Zi
Characterization of phenol metabolization by P. stutzeri N2 was proposed based on the identification of relevant metabolites and enzyme activities of catechol 1,2-oxygenase and catechol 2,3-dioxygenase. P. stutzeri N2 started to grow on 400 mg l−1 phenol with no obvious lag phase, and then phenol decomposition was rapidly completed within 32 h. Results of enzyme activities, UV spectrums of cultures, and the mass spectrum identification of cis, cis-muconic and 2-HMS, which showed that catechol C12O and C23O were acting simultaneously on the fission of the phenol ring. The existence of P-hydroxybenzoic acid and straight-chain saturated dicarboxylic acids in the culture medium showed that carboxylation and hydrogenation were involved during the phenol degradation. Metabolites containing five or four carbons indicated that catechol and its immediate ring-cleavage intermediates could be furthermore metabolized by P. Stutzeri N2. Therefore, P. stutzeri N2 which could degrade phenol with high efficiency and diverse pathways could have potential applications in the treatment of wastewater containing phenol.
研究领域:
环境微生物学
·
生物化学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Xiaoxue Liu,Jiao Yang,Jing Cheng,Yi Xu,Wen Chen,Yingchun Li
Development of nanomaterials with multienzyme-like activities (nanozymes) via a simple way has attracted paramounting attention. Generally, enzymatic activity is closely related to the size, surface state, material type, etc. Bimetallic oxides are very appealing owing to their mixed valence and structural advantages. Herein, we reported an eco-friendly strategy to synthesize Co 1.5 Mn 1.5 O 4 nanozyme via sol-gel method. This nanozyme functionally mimics four major enzymes, i.e. laccase, peroxidase (POD), oxidase (OXD), and catalase (CAT). Accordingly, a colorimetric sensing platform was designed to distinguish isomers of organic pollutants ‒catechol (CC) and hydroquinone (HQ) by using Co 1.5 Mn 1.5 O 4 as the sole catalyst. In particular, laccase-like activity of Co 1.5 Mn 1.5 O 4 enables it to directly oxidize CC into yellow o -benzoquinone with good linearity in the range of 1∼1000 μM and a detection limit of 0.35 μM. Meanwhile, HQ can discolor the oxidized substrate that was pre-oxidized with the aid of oxidase-like activity of the nanozyme (linear range: 0.05∼100 μM, detection limit: 0.04 μM). The established colorimetric method has been successfully utilized for selective sensing of CC, HQ in water samples with good selectivity and high sensitivity. Our study contributes to green synthesis of metal-based nanomaterials with multi-enzyme mimicking activities and uncovers new usage of nanozyme in discriminating of environmental pollutants.
研究领域:
环境科学
·
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 46
·22412-22418
·
IF 3.925
Xiaoyan Jiang,Min Wang,Li Hou,Tianran Lin
A one-step colorimetric sensing platform had been constructed for catechol determination based on polyacrylic acid-coated cerium oxide (PAA-CeO2) with a significant laccase-like activity. Compared with the traditional nanozyme-based colorimetric determination methods for catechol, the PAA-CeO2 nanozyme with laccase-like activity did not require biotoxic and poor stability H2O2 in this method. PAA-CeO2 could directly catalyze the oxidation of catechol to o-quinone in the presence of dissolved O2, and the oxidation product was coupled with 4-aminoantipyrine (4-AAP) to form a pink product at the maximum absorption of 512 nm (OD512). By utilizing the relationship between the concentration of catechol and the OD512 intensity to achieve sensitivity quantitative analysis and visual determination of catechol in an ordered and one-step reaction, which provided a dynamic range from 0.5 to 50 μmol L−1 within a low detection limit of 0.121 μmol L−1. In addition, this colorimetric sensing platform based on PAA-CeO2 had satisfactory repeatability and stability, which could be used for the catalytic degradation of other phenolic compounds in the environment to ensure public health and environmental safety.
研究领域:
生物化学
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环境科学
·
分析化学
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产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND MICROBIOLOGY
·
2022
·Vol. 58
·期 6
·796-805
·
IF 1.065
Li P.,Jiang Y.,Fei Y. Y.,Zeng X. C.
Abstract Benzo(a)pyrene (BaP) is one of the most common organic pollutants in the environment, and its microbial removal has great ecological and economic value. Here, using BaP (50 mg/L) as the sole carbon source, dynamic changes in camel rumen and gut bacterial communities were analyzed by high-throughput sequencing. Next, cultivable BaP-degrading isolates were obtained, and their degradation characteristics were explored. The relative abundance of most bacteria in the gut and rumen underwent apparent changes after BaP treatment. The rumen and gut bacteria have the ability to degrade BaP but fluctuated during iterative culturing from the first to the fifth generation of gut communities displaying the highest BaP degradation efficiency (BDE) (74.4 and 81.1%, respectively). Moreover, 37 isolates exhibiting BDE were identified. Among these isolates, CL9 ( Klebsiella sp.), CL16 ( Ochrobactrum sp.), CC6 ( Ochrobactrum sp.), and CC16 ( Bacillus sp.) showed BDEs of up to 70.8, 69.3, 68.4, and 76.2%, respectively. The enzyme catechol-2,3-dioxygenase was involved in BaP degradation in these four BaP-degrading isolates and represented the main BaP degradation pathway in isolates CL9 and CL16; however, the relative expression level of the gene phnAc was higher in isolates CC6 and CC16 than in isolates CL9 and CL16. Our results provided promising bacterial resources for the removal of BaP and laid the foundation for the application of animal gastrointestinal bacteria to degrade environmental pollutants.
研究领域:
环境微生物学
·
动物科学
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生物修复
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DOI
高影响因子
POLYMER COMPOSITES
·
2020
·Vol. 42
·期 1
·141-152
·
IF 2.265
Yuan Chen,Xiaoqing Wu,Junfu Wei,Hailiang Wu,Jing Fang
Substantial amount of polyethylene terephthalate/cotton (PET/cotton) blend fabrics have been handled as waste especially in recent decades on account of the technological barrier and/or low economic benefit of recycling PET from PET/cotton fabrics. Herein, a facile and effective approach was utilized to modify PET/cotton fabrics with co-deposition of polyethyleneimine (PEI) and catechol (CCh) to improve the interfacial bonding of fiber-matrix. The surface morphology and composition of fabrics were investigated by FESEM, ATR/FTIR, and XPS. Meanwhile, the surface properties were analyzed via dynamic contact angle. The results indicated that the PEI-CCh co-deposition aggregates were modified onto fabric surface through the synergy of intermolecular hydrogen bonding and π-π stacking. Interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of modified PET/cotton reinforced composites were 39.71% and 50.25% higher than that of untreated PET/cotton reinforced composites, respectively. Furthermore, the enhancement mechanisms of composites are systematically discussed.
研究领域:
材料科学
·
纺织工程
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产品关联
DOI
高影响因子
Analytical Methods
·
2014
·Vol. 6
·期 18
·7420-7425
·
IF 1.938
Zhuo Li,Ruiling Sun,Yongnian Ni,Serge Kokot
An efficient method for the analysis of hydroquinone at trace levels in water samples has been developed in the form of a fluorescent probe based on graphene quantum dots (GQDs). The analytical variable, fluorescence quenching, was generated from the formation of benzoquinone intermediates, which formed during the catalytic oxidation of hydroquinone by horseradish peroxidase (HRP). In general, the reaction mechanism involved hydroquinone, as an electron acceptor, which affected the surface state of GQDs via an electron transfer effect. The water-soluble GQDs were directly prepared by the pyrolysis of citric acid and with the use of the mentioned hybrid enzyme system, the detection limit for hydroquinone was as low as 8.4 × 10−8 M. Furthermore, this analysis was almost unaffected by other phenol and quinine compounds, such as phenol, resorcinol and other quinines, and therefore, the developed GQD method produced satisfactory results for the analysis of hydroquinone in several different lake water samples.
研究领域:
分析化学
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环境科学
·
生物化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Youjun He,Sheng Gao,Zaijun Lu
Mussel adhesive proteins (MAPs) are of an excellent adhesive property . The catechol structure (i.e., 1, 2-dihydroxybenzene) of 3, 4-dihydroxy-phenylalanine (DOPA) plays a key role in MAPs adhesion. Inspired by the MAPs adhesion, we synthesized catechol-based benzoxazine monomers (BOZ-ca) via Mannich reaction of catechol, aniline and paraformaldehyde, and then the polybenzoxazine containing catechol groups (PBOZ-ca) was obtained through the ring-opening polymerization of BOZ-ca in this work. The structure of BOZ-ca was characterized by 1 H NMR, 13 C NMR and FTIR. Interestingly, the DSC results show that the autocatalytic polymerization effect of BOZ-ca owing to the existence of phenolic hydroxyl groups decreases the polymerization temperature of BOZ-ca by ca. 80 °C compared with common benzoxazine monomers. The adhesion study results indicate that the catechol structure of PBOZ-ca increases its lap shear adhesion strength by 53% compared with common benzoxazine monomers, up to ∼2.61 MPa. The introduction of mussel-inspired structure provides a new design routine for the improvement of polybenzoxazine adhesion property.
研究领域:
材料科学
·
生物仿生学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Youjun He,Jiming Chen,Irum Rafique,Zaijun Lu
The catechol groups in mussel adhesive proteins exhibit excellent adhesion property to the skin and tissue surfaces. Inspired by catechol groups, the aim of this study is to synthesize the star-shaped polycaprolactone bio-adhesive bearing catechol end-groups (s-PCL 19 -CA 9 ). Firstly, star-shaped polycaprolactone was synthesized through ring-opening polymerization of caprolactone monomers initiated by β-cyclodextrin, and then the s-PCL 19 -CA 9 was obtained through end-group functionalization using succinic anhydride and dopamine. The structure of s-PCL 19 -CA 9 was characterized by 1 H NMR, FTIR, and static light scattering. Adhesive strength measurements demonstrate that the incorporation of multifunctional catechol groups endows the crosslinked s-PCL 19 -CA 9 with an excellent adhesion property (102 ± 10 kPa). The swelling ratio of crosslinked s-PCL 19 -CA 9 is as low as 3.4 ± 0.2% owing to the hydrophobicity of PCL and the crosslinking structures. Besides, the cytotoxicity studies show that s-PCL 19 -CA 9 is noncytotoxic. The TGA measurements indicate that s-PCL 19 -CA 9 possesses a good thermal stability. Therefore, this work provides a new way for developing multifunctional bio-adhesives with excellent adhesion property and low swelling ratio.
研究领域:
材料科学
·
生物医学工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Yu Xie,Yeping Wu,Xiuli Zhao,Hanbing Ma,Ping Zhang,Yinyu Zhang
As the non-covalent interfacial interactions of adhesive-metal bonds are inherently susceptible to disruption by water molecules, bonding structures often culminate in failure under hydrothermal conditions. Herein, we designed a novel primer composed of catechol-based epoxy adhesive containing the aniline trimer, which enhances both the adhesion properties and anti-corrosive performance for ordinary epoxy adhesive. The lap shear strength of Q235 steel coated with EP-AT-CMB increased from 8.36 MPa to 22.07 MPa compared to untreated substrates. Notably, the adhesion strength of Q235 steel coated with EP-AT-CMB remained robust at 14.16 MPa after being immersed in water for 4 days, whereas the untreated samples experienced a near-total loss of adhesion strength. The superior anti-corrosion capability of EP-AT-CMB specimens is attributed to two factors: (1) the high density of hydrogen bonds of the primer/metal interface exhibit a barrier property for water molecules; (2) the electroactivity aniline trimer, which facilitates the formation of a passive film composed of Fe 2 O 3 and Fe 3 O 4 . The synergism between the catechol structure of the primer and the electrochemical behavior of the aniline trimer enhances the durability of the adhesive structure, offering a practical and durable primer material for a wide range of applications
研究领域:
材料科学
·
腐蚀与防护
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Jing Tang,Xiaoqing Ma,Jing Liu,Shengbiao Zheng,Jianfei Wang
In this study, an electrochemical sensor for the simultaneous detection of hydroquinone (HQ) and catechol (CC) was fabricated on glassy carbon electrode (GCE) modified with graphene quantum dots (GQDs). The prepared GQDs were characterized by transmission electron microscope and fourier transform infrared spectroscopy. The GQDs/GCE, which prepared by electrodeposition method, and characterized by electrochemical impedance spectra, exhibited excellent electrochemical catalysis and conductive properties for HQ and CC. Owing to the high electroactive surface area, good electrocatalytic activity and low charge transfer resistance of GQDs, HQ and CC can be easily measured simultaneously for the large separation of oxidation peak potentials (113 mV) and do not interfere with each other. Under the optimal experimental condition, the oxidation peak currents were linear to HQ/CC in the range from 0.5 μM to 100 μM with the same low detection limits of 0.08 μM (S/N=3). Simultaneous determination of HQ and CC with such electrode was conducted in river water samples with reliable recovery between 97.90% and 103.9%.
研究领域:
分析化学
·
电化学
·
环境监测
·
传感技术
·
水污染检测
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING COMMUNICATIONS
·
2023
·
IF 2.5
Yilin Zhao,Nengcheng Zhou,Min Hua,Xiuxia Guo,Wenxing Zhang,Huichun Jiang,Xuhai Pan,Juncheng Jiang
In this article, the thermal stability of tert-butyl perbenzoate (TBPB) mixed with different concentrations of toluene and p-tert-butylcatechol (TBC) was investigated. The exothermic onset temperature (T0), the heat of decomposition (ΔH), and the adiabatic temperature rise (ΔTad) of the samples were obtained by differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry. The apparent activation energy (Ea) and the maximum reaction rate arrival time under adiabatic conditions were obtained by adiabatic kinetic calculations for 8 h (TD8) and 24 h (TD24). Based on Semenov’s theory, the self-accelerated decomposition temperature was calculated as a support for safe storage and transport. The results of DSC and Phi-TEC II showed that toluene was effective in reducing the thermal hazard during the decomposition of TBPB. The addition of TBC caused side reactions. The moderate addition of toluene and TBC improves the thermal stability of TBPB and can improve the safety of TBPB in industrial applications.
研究领域:
化学工程
·
安全科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）