JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
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2018
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IF 3.638
Cailan Li,Ping Huang,Kambo Wong,Yifei Xu,Lihua Tan,Hanbin Chen,Qiang Lu,Chaodan Luo,Chunlai Tam,Lixiang Zhu,Ziren Su,Jianhui Xie
In this study, we examined the anti-Helicobactor pylori effects of the main protoberberine-type alkaloids in Rhizoma Coptidis. Coptisine exerted varying antibacterial and bactericidal effects against three standard H. pylori strains and eleven clinical isolates, including four drug-resistant strains, with minimum inhibitory concentrations ranging from 25 to 50 μg/mL and minimal bactericidal concentrations ranging from 37.5 to 125 μg/mL. Coptisine’s anti-H. pylori effects derived from specific inhibition of urease in vivo. In vitro, coptisine inactivated urease in a concentration-dependent manner through slow-binding inhibition and involved binding to the urease active site sulfhydryl group. Coptisine inhibition of H. pylori urease (HPU) was mixed type, while inhibition of jack bean urease was non-competitive. Importantly, coptisine also inhibited HPU by binding to its nickel metallocentre. Besides, coptisine interfered with urease maturation by inhibiting activity of prototypical urease accessory protein UreG and formation of UreG dimers and by promoting dissociation of nickel from UreG dimers. These findings demonstrate that coptisine inhibits urease activity by targeting its active site and inhibiting its maturation, thereby effectively inhibiting H. pylori. Coptisine may thus be an effective anti-H. pylori agent.
研究领域:
微生物学
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药理学
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生物化学
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DOI
PubMed
高影响因子
LANGMUIR
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2020
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IF 3.557
Ming Luo,Shouli Li,Jieshuo Wan,Chenglin Yang,Beidi Chen,Jianguo Guan
Enzyme-powered micro/nanomotors propelled by biocompatible fuels generally show a weak propulsive force, which greatly limits their applications in complex biological environments. Herein, we have developed a novel and versatile approach to significantly enhance the propulsion of enzyme-powered micromotors by multilayered assembly of enzymes. As an example, multilayers of biotinylated ureases (BU) were asymmetrically immobilized on biotinylated Janus Au/magnetic microparticles (MMPs) with the assistance of streptavidin (SA). When the mass ratio of BU into SA and the amount of BU used in the assembly process are increased, the amount of urease immobilized on the biotinylated Janus Au/MMPs increased monotonously while the migration speed of the micromotor was augmented gradually until a saturated value. The as-optimized micromotors can be self-propelled with an average speed up to about 21.5 ± 0.8 μm/s at physiological urea concentrations (10 mM), which is five times faster than that of the monolayered counterparts and two times faster than that of the previously reported values. Owing to the enhanced thrust, the micromotors can move in liquids with viscosities similar to that of blood. In addition, with the inherent magnetic property of MMPs, the micromotors can exhibit fast magnetic separation and controllable motion direction by external magnetic fields. Our results provide a new pathway for designing high-efficient enzyme-powered micro/nanomotors and thereby promote their biomedical applications.
研究领域:
生物医学工程
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纳米技术
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2017
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IF 2.269
Kai Huang,Tao Zhang,Bo Jiang,Wanmeng Mu,Ming Miao
l -Ornithine, a non-protein amino acid, is widely used as a food supplement and nutrition product that is usually produced by the enzymatic hydrolysis of l -arginine. However, urea, a by-product, complicates purification of l -ornithine. Here, we describe a highly efficient coupled system, which involves Rummeliibacillus pycnus arginase and Jack bean urease, for the production of l -ornithine without urea residue. Although R. pycnus arginase exhibited the highest enzyme activity at pH 9.5 with Mn 2+ , it could be activated by Ni 2+ at 70 °C and pH 6.5. Kinetic study showed that, compared with Mn 2+ -containing arginase, Ni 2+ -containing arginase had a higher substrate affinity and catalysis efficiency. Based on the properties of commercial Jack bean urease and recombinant arginase, both enzymes showed robust activity at pH 6.5 and 40–50 °C. Using a coupled system involving arginase and urease for bioconversion, l -ornithine production of 37.8 g l −1 was achieved with a 99.7% molar yield within 5 h. Thus, this coupled system represents an applicable strategy for the biosynthesis of l -ornithine.
研究领域:
生物化学
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酶工程
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生物技术
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DOI
高影响因子
JOURNAL OF STRUCTURAL CHEMISTRY
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2022
·Vol. 63
·期 8
·1371-1381
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IF 1.004
Jiang J.,Liu B.,Liu Y.,Jing C.,You Z.
Abstract Two new zinc(II) and nickel(II) complexes, [Zn 2 L(μ 2 -η 1 :η 1 -CH 3 COO)(μ 2 -η 1 :η 2 -CH 3 COO)] n ( 1 ) and [Ni 2 (HL) 2 (H 2 O) 2 (μ 1,3 -N 3 )]Cl·2H 2 O ( 2 ·2H 2 O), where L is the doubly deprotonated form of 4,4′-dimethoxy-2,2′-(propane-1,3-diyldiiminodimethylene)diphenol (H 2 L), were synthesized and characterized by elemental analyses, infrared and electronic spectroscopy, as well as single crystal X-ray diffraction. Complex 1 is a bidentate bridging and chelating bridging acetate bridged polymeric zinc complex. In the asymmetric unit of the complex, one Zn atom is in distorted trigonal bipyramidal coordination, and the other one is in octahedral coordination. Complex 2 ·2H 2 O is an end-to-end azide bridged dinuclear nickel complex. The Ni atoms are in octahedral coordination. The inhibitory property on Jack bean urease of the complexes was studied, and the nickel complex has effective activity.
研究领域:
无机化学
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生物化学
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DOI
高影响因子
CELLULOSE
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2017
·Vol. 25
·期 1
·233-243
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IF 3.417
Lv Miaomiao,Ma Xiaofei,Anderson Debbie P.,Chang Peter R.
Cellulose spheres were selected as an economical and biodegradable carrier for urease immobilization. The high crystallinity cellulose spheres (Ces) were crosslinked using citric acid and then oxidized using sodium periodate to produce aldehyde groups on the Ces surface that would bind covalently with the amino groups of urease through a Schiff base reaction. Ces, the obtained dialdehyde cellulose spheres (DACes) and cellulose spheres immobilized by urease (UrCes) were characterized by FTIR, XRD, SEM and TG. The results demonstrated the successful modification of Ces and immobilization of urease, along with the retention of the original spherical morphology and improved thermal stability. As an adsorbent, UrCes had both a greater adsorption capacity for urea and a greater specific selective adsorption than DACes. Urease was respectively immobilized on DACes with 19, 31 and 45% aldehyde contents to obtain UrCes1, UrCes2 and UrCes3. The maximum removal capacities of UrCes1, UrCes2, and UrCes3 for urea were 243.3, 276.2, and 187.6 mg g −1 , while only 10.71, 15.08 and 20.50 mg g −1 l -phenylalanine were adsorbed, respectively.
研究领域:
生物化学
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环境科学
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产品关联
DOI
高影响因子
Frontiers in Microbiology
·
2024
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IF 4
Feng Zhong,Li Hui,Hao Yajie,Peng Chang,Ou Ling,Jia Junwei,Xun Mingjin,Zou Yuanjing,Chen Meiyun,Zhang Guimin,Yao Meicun
Background: Helicobacter pylori (H. pylori) is thought to primarily colonize the human stomach and lead to various gastrointestinal disorders, such as gastritis and gastric cancer. Currently, main eradication treatment is triple or quadruple therapy centered on antibiotics. Due to antibiotic resistance, the eradication rate of H. pylori is decreasing gradually. Therefore, searching for anti-H. pylori drugs from herbal sources has become a strategy for the treatment. Our team proposed a Hezi Qingyou Formula (HZQYF), composed of Chebulae Fructus, Ficus hirta Vahl and Cloves, and studied its anti-H. pylori activity and mechanism.Methods: Chemical components of HZQYF were studied using UHPLC–MS/MS and HPLC. Broth microdilution method and agar dilution method were used to evaluate HZQYF’s antibacterial activity. The effects of HZQYF on expression of adhesion genes (alpA, alpB, babA), urease genes (ureE, ureF), and flagellar genes (flaA, flaB) were explored using Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR) technology. Effects on morphology and permeability of the extracellular membrane were studied using scanning electron microscopy (SEM) and N-phenylnaphthalen-1-amine (NPN) uptake. Effect on urease activity was studied using a urease kinetics analysis in vitro. Immunofluorescence staining method was used to examine the effect on adhesion. Western blot was used to examine the effect on cagA protein.Results: Minimum inhibitory concentration (MIC) values of the formula against H. pylori clinical strains and standard strains were 80–160 μg/mL, and minimum bactericidal concentration (MBC) values were 160–320 μg/mL. The formula could down-regulate the expression of adhesion genes (alpA, alpB, babA), urease genes (ureE, ureF) and flagellar genes (flaA, flaB), change the morphology of H. pylori, increase its extracellular membrane permeability, and decrease its urease activity.Conclusion: Present studies confirmed that HZQYF had promising in vitro anti-H. pylori activities and demonstrated its possible mechanism of action by down-regulating the bacterial adhesion, urease, and flagellar gene expression, which provided scientific bases for further clinical investigations.
研究领域:
微生物学
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药理学
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中医药
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分子生物学
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2020
·
IF 2.627
Xiao Liang,Qing Li,Zhiyuan Shi,Shaowei Bai,Quanshun Li
Enzyme immobilization has been accepted as an efficient technique for improving the stability and recyclability of enzymes. Herein, biomimetic mineralization strategy was employed to achieve the immobilization of urease in a type of metal–organic frameworks (zeolite imidazolate framework-8, ZIF-8), and the immobilized enzyme urease@ZIF-8 was systematically evaluated for its structure, activity, stability and recyclability, using the hydrolysis of urea as a model. The entrapment of urease was found to be realized in a synchronous manner with the formation of ZIF-8 crystal. The loading of urease in ZIF-8 was measured to be ca. 10.6% through the bicinchoninic acid (BCA) protein assay. The encapsulated urease could efficiently maintain its native conformation, which endowed the immobilized urease with excellent activity and stability, even in harsh conditions ( e.g. , in the presence of trypsin, acidic or alkali conditions, or at high temperature). Further, urease@ZIF-8 exhibited good recyclability during the degradation of urea, in which it could keep 58.86% of initial activity after being used for 5 cycles. Thus, biomimetic mineralization could be potentially utilized as a promising method to prepare immobilized ureases with superior activity, stability and recyclability, thereby facilitating the construction of efficient catalysts for industrial biocatalysis and biosensing.
研究领域:
生物化学
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酶工程
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材料科学
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产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Xiandong Zeng,Jie Liu,Ziping Zhang,Shu Kong
In this paper, a potentiometric biosensor was fabricated by immobilizing urease into chitosan- poly(vinyl alcohol) hydrogel film at the surface of a pH electrode. Based on the inhibition effect of Hg 2+ to the activity of immobilized urease, the proposed biosensor was used for detection of Hg 2+ . The results showed that the inhibition rate exhibited a good linear relationship with the logarithm of Hg 2+ concentration in the range from 0.002 μM to 2μM. Defined as 10% inhibition rate, the detection limit was found to be 0.001 μM. The concentration for 50% inhibition rate was calculated to be 0.03μM. Furthermore, the proposed biosensor exhibited excellent selectivity to Hg 2+ . Other heavy metal ions, such as Ag + , Cu 2+ , Pb 2+ , Cd 2+ have littler influence on Hg 2+ determination. The biosensor was successfully applied for determination of Hg 2+ in industrial wastewater samples. The results obtained by the biosensor were consistent with those measured by inductively coupled plasma mass spectrometry (ICP-MS) method.
研究领域:
环境科学
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分析化学
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Yi-Xin Xie,Wen-Chieh Cheng,Zhong-Fei Xue,Lin Wang,Md Mizanur Rahman
Although single bacteria have been applied to the Polycyclic Aromatic Hydrocarbons (PAHs) remediation, its efficacy is severely restricted by long degradation periods and low efficacy. A microbial symbiotic system founded by two or more bacterial strains may be an alternative to traditional remediation approaches. Its construction is, however, hampered by antagonistic interactions and remains challenging. The present work proposed a microbial symbiotic system consisting of the naphthalene degrading bacteria and the non-PAHs degrading bacteria and improved their interspecies interactions by using sequential inoculation. The non-PAHs degrading bacteria were inoculated after the inoculation of the naphthalene degrading bacteria. The sequential inoculation not only promoted the non-PAHs degrading bacteria to use the metabolites of the naphthalene degrading bacteria as an energy source but developed a resistance of the two bacterial strains to naphthalene. Vaterite and aragonite were identified following urea hydrolysis by the non-PAHs degrading bacteria. The faster precipitation rate in naphthalene degradation by the symbiotic system elevated the proportion of vaterite, allowing more naphthalene and its metabolites to be wrapped in or attached to minerals with the bacteria through the physisorption (van der Waals force) and chemisorption (Ca-π interaction with aromatic rings) and promoting the formation of aggregates. The formation of aggregates further reduced the mobility of naphthalene. Results indicate that 40% of naphthalene in the non-inoculated sterile control group was quickly released into the atmosphere, causing serious public concerns regarding health safety. According to the thermogravimetry-gas chromatography mass spectrometry (TG-GC/MS) analysis, no trace of naphthalene was found in the samples, indicating that the degrading bacteria fully degraded naphthalene after its adsorption. As a result, the degradation efficiency of 100% was attained using the symbiotic system even at 200 mg/L naphthalene. The findings underscore the relative merits of the symbiotic system applied to the remediation of naphthalene in an aqueous solution.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
HELICOBACTER
·
2023
·
IF 4.4
Zelin Zhang,Xingchi Chen,Bin Li,Tingting Xia,Xiaobin Wu,Chao Wu
Background Urease subunit B (UreB), a conserved and key virulence factor of Helicobacter pylori ( H. pylori ), can induce the host CD4 + T cell immune responses to provide protection, but less is known regarding CD8 + T cell responses. The characteristics of H. pylori -specific CD8 + T cell responses and the mechanism underlying antigen processing and presentation pathways remain unclear. This study was focus on protective antigen recombinant UreB (rUreb) to detect specific CD8 + T cell responses in vitro and elucidate the mechanism of UreB antigen processing and presentation. Methods The peripheral blood mononuclear cells (PBMCs) collected from H. pylori -infected individuals were stimulated with rUreB in vitro to detect specific CD8 + T cell responses after co-culture with rUreB-pulsed autologous hMDCs. Through blocking assay, we investigated the potential pathway of UreB antigen processing and presentation via the cytosolic pathway or vacuolar pathway. The cytokines production of UreB specific CD8 + T cell were evaluated as well. Results We demonstrated UreB can induce specific CD8 + T cell immune responses in H. pylori infected individuals. Importantly, we characterized that UreB were mainly processed by proteasome instead of lysosomal proteases and presented through cytosolic pathway of cross-presentation, which requires endoplasmic reticulum–Golgi transport and newly synthesized MHC-I molecules, to induce functional-specific CD8 + T cell (IFN-γ + TNF-α + Grz A+ Grz B+) responses. Conclusions These results suggest that H. pylori UreB induces specific CD8 + T cell responses through cytosolic pathway of cross-presentation in infected individuals.
研究领域:
免疫学
·
病原生物学
·
医学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2013
·
IF 0
Lei Wang,Sha Wang,Xiangyun Deng,Yucang Zhang,Chunrong Xiong
Coconut shell activated carbon (AC)-tethered urease (from jack bean) was successfully developed to degrade urea in a packed bed reactor. The loading capacity of urease in AC was 78.8 mg/g. The tethered enzyme showed a maximum activity at 70 °C and pH 7.2. For higher than 75% of the maximum activity, the tethered urease showed a broader temperature range of 42–80 °C compared to 45–75 °C for the free enzyme. Similarly, the tethered urease had an increased stability against the changes of pH. The Km value of the free urease was 0.271 mol/L and 0.345 mol/L for the tethered one. This may be caused by the conformational changes of the enzyme. The Vmax values were 0.215 and 0.110 mol/min for the tethered and free ureases, respectively, which is reflected by an increase in catalytic activity. The catalytic degradation of urea was performed in a packed bed reactor. The remaining activity of the tethered urease was over 80% after 50 h of operation.
研究领域:
生物化学
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环境科学
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DOI
JOURNAL OF CONTROLLED RELEASE
·
2025
·
IF 11.5
Penghui He,Chunting He,Rong Guo,Yangsen Ou,Yu Chang,Zhiqiang Xie,Xue Tang,Yanhua Xu,Yuanhao Zhao,Hairui Wang,Zhaofei Guo,Shuting Bai,Zhengjun Chen,Fan Fan,Guangsheng Du,Xun Sun
Mucosal vaccines are considered an ideal choice for combating mucosal pathogens due to their ability to neutralize pathogens at the first line of defense. However, the development of mucosal subunit vaccines is constricted by rigorous challenges, such as low immunogenicity, poor antigen delivery efficiency, and mucosal tolerance. Here, a buccal microneedle patch incorporated with engineered nanoparticles loaded with urease B subunit (rUreB) was developed to overcome the above challenges. Specifically, an engineered nanocarrier was developed to protect the antigen and modulate its release profile. Then, the nanoparticles were enriched to form microneedle tips with superior mechanical and waterproof properties, allowing effective penetration of the buccal mucosa and resistance to salivary washout. Besides, the microneedles demonstrated an S-curve antigen release pattern which was crucial for the recruitment of antigen presenting cells (APCs) and the downregulation of mucosal tolerogenic DCs and Treg cells. The buccal microneedle vaccine without any immune stimulators induced potent systemic and mucosal immune responses, resulting in superior protection of mice from the oral challenge of Helicobacter pylori . These results suggested that the rationally designed buccal microneedle vaccine can effectively overcome mucosal delivery barriers and mucosal tolerance, providing a promising alternative strategy for mucosal vaccination of subunit antigens.
研究领域:
疫苗学
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生物医学工程
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免疫学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）