COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2015
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IF 2.752
Xi-Zhi Zhang,Yang Zhou,Wei Zhang,Yu Zhang,Ning Gu
Prussian blue (PB) and gold modified polystyrene (PS) nanocomposites (PS@Au@PB) were synthesized and characterized by TEM, SEM, FTIR, UV–vis and EDS. The formation mechanism of PB induced by gold nanoparticles on PS nanospheres was proposed. The peroxidase-like and catalase-like activities of the synthesized nanocomposites were investigated. Peroxidase-like activity was found to follow Michaelis–Menten kinetics. The calculated kinetic parameters indicated that the PS@Au@PB nanocomposites possess strong affinity with the substrates and high catalytic activity. A sensitive method for glucose detection was developed using glucose oxidase (GO x ) and PS@Au@PB nanocomposites. The detection limit for glucose was determined to be as low as 3.9 μM and the linear range was from 15.6 to 250.0 μM. It suggests that PS@Au@PB nanocomposites can serve as a useful reagent in some biological detections.
研究领域:
生物化学
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纳米医学
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分析化学
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DOI
高影响因子
RSC Advances
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2014
·Vol. 4
·期 33
·17387-17392
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IF 3.708
Wengfeng Zhu,Jian Zhang,Zhenchao Jiang,Weiwei Wang,Xiaoheng Liu
In this paper, bright and high-quality carbon dots (CDs) were prepared by refluxing a membranous carbonized β-cyclodextrin in nitric acid. The structure and optical properties of the CDs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), fluorescence spectrophotometry (FL), X-ray diffraction (XRD) and Raman spectroscopy. The mechanism for the formation of the CDs is also discussed. As-prepared CDs could be used as peroxidase mimics for the detection of H2O2. The results indicate that the CDs are capable of rapid and sensitive detection of H2O2 in the linear range from 2 × 10−6 to 5 × 10−4 mol L−1 and the limit of detection of H2O2 is as low as 1 × 10−6 mol L−1. More importantly, the peroxidase-like activity of the CDs is expanded to the detection of some oxidative ions (such as Fe3+ and Ag+). The linear ranges for Fe3+ and Ag+ were 8 × 10−6 to 1 × 10−4 mol L−1 and 5 × 10−6 to 1 × 10−4 mol L−1 respectively, with corresponding detection limits of 8 × 10−7 mol L−1 and 5 × 10−7 mol L−1 respectively.
研究领域:
材料科学
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分析化学
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DOI
高影响因子
FOOD CONTROL
·
2024
·
IF 5.6
Kai Jiang,Yiwei Huang,Rui Cui,Yuyue Qin,Thanapop Soteyome,Margaret Brennan,Charles Brennan
In this study, we screened out the dominant spoilage microorganisms during the cold storage of morels, prepared composite paper with a targeted selection of antimicrobial active substances, applied the composite paper to morels for cold storage and preservation, and investigated the changes of physicochemical indexes, flavor-presenting nucleotides and enzyme activities throughout the process of storage, and evaluated the freshness preservation effect. The pathogenic microorganisms during the natural spoilage of Morels were isolated and purified at 4 °C. The dominant spoilage microorganisms obtained were: bacterium B1 ( Lelliia amnigena ), fungi F2 ( Paecilomyces penicillatus ) and F3 ( Mucor hiemalis ). Inhibition experiments were carried out by selecting various active antimicrobial agents—lemon essential oil, clove essential oil and nisin (NI)—against the dominant spoilage microorganisms B1, F2 and F3. Comparing the inhibitory effects, NI was selected as an inhibitor for the dominant spoilage microorganisms following comprehensive consideration. The antimicrobial system (NI/C-CNC) was prepared by incorporating NI into carboxylated cellulose nanocrystals (C-CNC), and it exhibited a strong blocking effect on ultraviolet rays, which became more pronounced with the increase of NI addition. The composite paper NI-C was prepared using the NI/C-CNC antimicrobial system and absorbent paper (100 % virgin wood pulp), which showed better mechanical properties and reduced water vapor transmission rate (WVP). NI-C composite paper was applied to the preservation of morels, which effectively inhibited the dominant pathogenic bacteria. The flavor 5′-nucleotides were effectively protected, and it significantly slowed down the change in hardness during storage of morels. It also inhibited lipid peroxidation, as evidenced by the accumulation of malondialdehyde (MAD) content and reactive oxygen species (ROS), and had a positive effect on the control of enzyme activity. NI-C antimicrobial composite paper has good application prospects in the field of packaging of morels.
研究领域:
食品科学
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微生物学
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产品关联
DOI
高影响因子
Microorganisms
·
2024
·Vol. 12
·期 7
·1381
·
IF 4.1
Xuezhi Shao,Hongliang Fang,Tao Li,Liyan Yang,Dengfeng Yang,Lixia Pan
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that catalyze the oxidative cleavage of recalcitrant polysaccharides. There are limited reports on LPMOs capable of concurrently catalyzing the oxidative cleavage of both cellulose and chitin. In this study, we identified and cloned a novel LPMO from the newly isolated bacteriumChitinilyticum aquatileCSC-1, designated asCaLPMO10. When using 2, 6-dimethylphenol (2, 6-DMP) as the substrate,CaLPMO10 exhibited optimal activity at 50 °C and pH 8, demonstrating good temperature stability at 30 °C. Even after a 6 h incubation at pH 8 and 30 °C,CaLPMO10 retained approximately 83.03 ± 1.25% residual enzyme activity. Most metal ions were found to enhance the enzyme activity ofCaLPMO10, with ascorbic acid identified as the optimal reducing agent. Mass spectrometry analysis indicated thatCaLPMO10 displayed oxidative activity towards both chitin and cellulose, identifying it as a C1/C4-oxidized LPMO.CaLPMO10 shows promise as a key enzyme for the efficient utilization of biomass resources in future applications.
研究领域:
生物化学
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微生物学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Jiaqing Huang,Cailin Qiao,Xinrou Wang,Yuwei Gao,Jinsong Zhao,Huibo Luo,Yongzhong Wang,Changjun Hou,Danqun Huo
Pichia kudriavzevii was one of the important aroma-producing fungi in the solid-state fermentation of Baijiu, and immobilization was an effective strategy for improving microbial performance. Herein, P. kudriavzevii cells were immobilized in a gel network that crosslinked by chitosan and sodium alginate to form sodium alginate/chitosan- P. kudriavzevii microspheres (SA/CS-PMs). Their structural characteristics and formation processes were characterized by SEM and FT-IR. The effect of synthesis conditions on the performance of microspheres were determined by single-factor experiments. Under the optimal conditions, the SA/CS-PMs could increase the amylase activity of the fermentation broth by 57.18%, the esterase activity by 66.13%, the content of ester by 67.04%, and could be reused at least three times. Further research results indicated that the content of ester could be increased significantly in Baijiu solid-state fermentation with the SA/CS-PMs. In conclusion, the SA/CS-PMs could improve the ester production ability of P. kudriavzevii by increasing the esterase activity, which was a valuable exploration of directional biosynthesis and a feasible strategy to improve solid-state fermentation quality.
研究领域:
微生物学
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发酵工程
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食品科学
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMISTRY
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2023
·
IF 5.4
Xiuyuan Wang,Shusheng Yu,Yuqiu He,Fuan Wang,Xiaoqing Liu
Comprehensive Summary A label-free deoxyribozyme (DNAzyme) biosensor for m 6 A demethylase activity detection is developed. When demethylase FTO (Fat mass and obesity-associated protein), an important m 6 A demethylase of ALKBH demethylase family is present, the m 6 A group is specifically demethylated, and the cleavage activity of DNAzyme is restored. This allows the cleavage product that contains G-quadruplex sequence to bind to thioflavin T (ThT) and generate fluorescence signals. The biosensor shows high specificity and sensitivity, and fast reaction speed. Our study demonstrates a new design of allosteric DNAzyme for sensing. This method represents the first label-free nucleic acid biosensor for FTO assay, providing a feasible route towards inhibitors screening.
研究领域:
生物化学
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分子生物学
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Chunyang Bao,Qiang Zhang
PEGylation and glycosylation are utilized in this research as different bioconjugation tools to modify proteins, yielding conjugates with different enzyme activity and assembled structure. Active succinimidyl esters are first synthesized through a facile one-step reaction for the alkyne-functionalization of proteins. Well-defined polymers with controlled MW, narrow dispersity and terminal azide groups, including thermoresponsive poly(PEG) and glycopolymers, are then synthesized via a combination of copper mediated living radical polymerization (Cu(0)-LRP) following azidation reaction. Copper catalyzed azide and alkyne cycloaddition reaction (CuAAC) is finally performed to conjugate poly(PEG) or glycopolymers with the alkyne-functionalized laccase from Trametes versicolor . The coupling of polymers induces further self-assembly of laccase-polymer conjugates into spherical nanoparticles with well dispersion stability and stimuli-responsive behaviours in water. Enzyme activity of the conjugates are also studied, during which the glycosylated laccase has shown relatively higher activity than the PEGylated laccase.
研究领域:
生物化学
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材料科学
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分子生物学
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DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 3.8
Zhi Wang,Jiaxing Zhang,Shengping You,Rongxin Su,Wei Qi
The extensive application of polyethylene terephthalate (PET) has led to severe environmental pollution. Enzymatic degradation provides a sustainable solution for PET recycling, but the limited hydrolytic activity of current PET hydrolases hinders its practical application. Here, we designed an Energy-Guided Accumulate Mutation Strategy (EGAMS) for the rational design of PET enzyme PHL7. By applying multiple rounds of evolution to enhance the degradation activity and thermostability of PHL7, we achieved the excellent PET degradation enzyme FlashPETase (PHL7 E148K/T158P/S184E/H185Y ) with 238.8% PET degradation activity of PHL7 and 82.93 °C melting temperature. FlashPETase completely degrades PET at 72 °C with an enzyme loading of 1.5 mg enzyme g PET −1 , without any substrate pretreatment or additional processing. As for PET substrates with high crystallinity, FlashPETase still performs well. Furthermore, molecular simulations revealed the structural mechanisms of FlashPETase’s enhanced activity and stability. In summary, the EGAMS protocol and the variants discussed in this work advance the fields of PET degradation and enzyme engineering, offering valuable insights for future research.
研究领域:
酶工程
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环境科学
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分子生物学
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产品关联
DOI
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2021
·
IF 3.307
Meiqi Wang,Weili Yu,Lijuan Shen,He Zheng,Xuan Guo,Jinyi Zhong,Tao Hu
Haloalkane dehalogenase DhaA can catalyze the hydrolytic cleavage of carbonhalogen bonds, along with production of the corresponding alcohol, a proton and a halide. However, DhaA suffers from poor environmental tolerance, such as sensitivity to high temperature, low pH and hypersaline. Arabinogalactan (AG) is a hydrophilic polysaccharide with highly branched long chains. DhaA was conjugated with AG to improve the environmental stability of DhaA in the present study. Each DhaA was averagely conjugated with 4∼5 AG molecules. Conjugation of AG essentially maintained the enzymatic activity of DhaA (91.4 %) without apparent structural alteration. The hydration layer formed by AG could reduce the solvent accessible area of DhaA and slow the protonation process, thereby improving the pH and high salt stability of DhaA. In particular, the remaining activities of the conjugate (AG-DhaA) were 35.3 % after treatment at pH4.0 for 1 h, and 80.8 % in 1 M NaCl after treatment for 16 h. As compared with DhaA, AG-DhaA showed slightly different kinetic parameters (K M of 1.90 μmol/L and k cat of 2.60 s -1).
研究领域:
生物化学
·
酶工程
·
环境生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Ming Ying,Manjunath D. Meti,Hong Xu,Yuhan Wang,Jialiang Lin,Zhibing Wu,Qingguo Han,Xu Xu,Zhendan He,Wenxu Hong,Zhangli Hu
The interaction of lipase with Ligupurpuroside B was studied by multiple spectroscopic techniques , enzyme activity and molecular modeling under simulative physiological condition. According to Stern-Volmer equation, fluorescence of lipase was quenched by Ligupurpuroside B via a static quenching mechanism because of formation of Ligupurpuroside B-lipase complex. Binding constants , number of binding sites & thermodynamic parameters were evaluated. The values of Δ G o (−25.085 kJ mol −1 ), Δ H o (−12.14 kJ mol −1 ) and Δ S o (+43.45 J mol −1 K −1 ) at 298 K indicated that Ligupurpuroside B-lipase interaction is spontaneous and hydrophobic interaction is the main force stabilizing the Ligupurpuroside B-lipase complex. The enzyme activity assay showed that Ligupurpuroside B inhibited lipase activity efficiently. Synchronous fluorescence spectra (SFS) suggested that Ligupurpuroside B is closer to Trp residues than to Tyr residues. All above experimental results were confirmed by molecular docking studies, which further indicated the binding site of Ligupurpuroside B on the surface of lipase, and the amino acid residues of lipase interacting with Ligupurpuroside B. Our present research work gives valuable information on the design of drugs with lipase as a carrier and should be useful for food industries.
研究领域:
生物化学
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药物设计
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食品科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Xiuting Hu,Yu Wang,Chengmei Liu,Zhengyu Jin,Yaoqi Tian
Uricase was conjugated with dextrin to improve its stability. Firstly, dextrin was succinylated into dextrin monosuccinate with the functional group, carboxylic acid, and dextrin monosuccinates with different degree of substitution (DS) were prepared. Secondly, dextrin-uricase conjugate was synthesized by uricase and dextrin monosuccinate, which was verified by size-exclusion chromatography and anion exchange chromatography . Thirdly, it was found that the conjugate degree of the dextrin-uricase conjugate was positively related to the DS of dextrin monosuccinate, but the activity was seriously lost and difficult to recover by α-amylase. When the molar ratio of dextrin monosuccinate (DS = 0.283) to uricase was 30:1, the conjugate degree of dextrin-uricase conjugate reached 22.1% and the activity was decreased to 40.4%. After triggered by α-amylase, the activity was recovered to 83.4%. Finally, the enzymatic properties of this dextrin-uricase conjugate were investigated and compared with those of free uricase. The optimal pH and temperature of the dextrin-uricase conjugate was 9.0 and 45 °C, respectively, whereas the optimal pH and temperature of free uricase was 8.5 and 45 °C, respectively. Furthermore, dextrin-uricase conjugate was more resistant to simulated physiological conditions and trypsin. These results suggested that the stability of uricase could be ameliorated by conjugation with dextrin.
研究领域:
生物化学
·
医学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Pengxi Li,Wangjing Zhai,Bingxue Li,Qiqi Guo,Yujue Wang,Yucheng Gu,Li Zheng,Fanrong Zhao,Xueke Liu,Peng Wang,Donghui Liu
Glyphosate, the most widely utilized herbicide, frequently coexists with nitrogen fertilizers such as urea in soil environments. Nitrogen cycling is a key process for maintaining soil ecological functions and nutrient balance. However, the effects of co-exposure to glyphosate and urea on this process have remained unclear. This study investigated the impact of co-exposure to glyphosate (10 mg/kg) and urea (260.87 or 347.83 mg/kg, equivalent to 180 or 240 kg N/ha) on soil nitrogen cycling through a 98-day incubation experiment. Soil nutrients, enzyme activities, bacterial community structure, and functional genes were analyzed. NH 4 + -N and NO 3 - -N contents significantly decreased by 44.70–53.43 % and 36.74–49.12 %, respectively. Co-exposure reduced bacterial diversity and altered nitrogen cycling genes, decreasing nifH while increasing amoA and nosZ , indicating reduced nitrogen input potential and increased inorganic nitrogen loss. Enzyme analysis confirmed excessive activation of nitrification and denitrification, lowering nitrogen availability. Partial least squares structural equation modeling (PLS-SEM) showed co-exposure indirectly decreased NH 4 + -N and NO 3 - -N via enhanced nitrate and nitrite reductase activities. The study highlights the complex interactions between herbicides and fertilizers in soil environments and underscores the need for further research to understand the implications for wider soil health and crop production in agriculture systems.
研究领域:
环境科学
·
微生物学
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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）