MICROCHIMICA ACTA
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2022
·Vol. 189
·期 12
·1-11
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IF 6.408
Wang Jing,Xu Wei,Zhou Lin,Zhang Tianqi,Yang Na,Wang Min,Luo Xuemei,Jin Lu,Zhu Huaijun,Ge Weihong
The peroxidase-like activity of MXene@Fe 3 O 4 nanocomposites and the relevant colorimetric application have been investigated for the first time. According to a kinetic study, MXene@Fe 3 O 4 nanocomposites displayed higher peroxidase activity than their individual components, and the catalytic process followed a ping-pong mechanism. The improved peroxidase-like activity of the MXene@Fe 3 O 4 nanocomposites was obtained due to the synergetic impact of the Fe 3 O 4 and MXene phases, the huge ion-accessible interface, and quick electron transfer channels in the nanocomposites. In the presence of hydrogen peroxide (H 2 O 2 ), the MXene@Fe 3 O 4 nanocomposites can catalyze the reaction of the colorless substrate 3, 3, 5, 5-tetramethylbenzidine (TMB) into oxidized TMB which revealed a blue color at 652 nm. After the introduction of glutathione (GSH), the blue color was gradually fading owing to the hydroxyl radical scavenging effect of glutathione. A colorimetric detection platform based on the peroxidase-like activity of the MXene@Fe 3 O 4 nanocomposites was developed for H 2 O 2 and GSH with a detection limit of 0.4 μM and 0.5 μM, respectively. The calibration plot for glutathione detection is calculated by absorbance difference at 652 nm, which ranged from 0.5 to 10 μM with a detection limit of 0.2 μM. The recoveries of GSH with different concentrations ranged from 93.76 to 108.50% and the relative standard deviation from 0.30 to 5.96%. This work significantly extends the application of MXene@Fe 3 O 4 nanocomposites in the construction of colorimetric sensors and reveals a satisfactory result in real sample analysis. Graphical Abstract
研究领域:
纳米材料
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分析化学
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生物传感器
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催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Chen Hsu,Hsin-Ya Tsai,Sheng-Dong Chen,Chi-Fon Chang,Nan-Wei Su
Dikinases function in multiple biological roles, including energy metabolism and antibiotic resistance, as shown by pyruvate phosphate dikinase and rifampin phosphotransferase. Despite their functional importance, the substrate scope and synthetic potential of dikinases remain elusive. Here, we identified a dikinase from Bacillus subtilis, namely phenolic phosphate synthetase (BsPPS), which regioselectively monophosphorylates a broad spectrum of polyphenols, including flavonoids, stilbenoids, curcuminoids, chalcones, anthraquinones, coumarins, and coumestans. BsPPS catalyzes ATP-dependent phosphorylation via a ping-pong mechanism, featuring autophosphorylation at His795 and the formation of a transient phosphohistidine intermediate. This enzyme defines a PPS-like protein family characterized by a conserved catalytic tetrad (Asp627, His629, His630, and His795) and a distinctive motif (DDHHFYIDAMLDAKAR) in the unprecedented substrate-binding domain. While most members of this family remain uncharacterized, the prevalence of PPS homologs in Bacillus spp. suggests a potential role in phenolic xenobiotic metabolism. Furthermore, PPS and its widespread homologs belong to a largely unexplored superfamily of phosphotransferases with diverse apparent functions and EC classifications. Although these enzymes share a conserved domain architecture, they display significant variation in their substrate-binding domains, indicating a vast unexplored biocatalytic toolbox. Our findings unveil a biocatalytic route for synthesizing diverse polyphenol monophosphates, opening avenues for phosphate prodrug development.
研究领域:
生物化学
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酶学
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结构生物学
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生物催化
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微生物学
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分子生物学
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药理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Dongchen Yang,Zexiu An,Jingqian Huo,Lai Chen,Haijiao Dong,Weidi Duan,Yaxin Zheng,Minghua Wang,Maoxia He,Shutao Gao,Jinlin Zhang
Developing stable and efficient cobalt-based catalysts for degradation of emerging contaminants (ECs) in water is deemed as a practical strategy to avoid secondary pollution in advanced oxidation processes (AOPs). Herein, we developed a ultrastable cobalt-based chainmail catalysts (Co-NC900) using 2, 2’-bipyridine-assistant pyrolysis method. More than 96.6 % of imidacloprid (IMD) in water could be degraded within 5 min in the presence of Co-NC900 and peroxymonosulfate (PMS). Amazingly, Co-NC900 still give 95 % degradation efficacy for IMD after15 runs. And only 0.083 μg L −1 of Co could be detected in the reaction mixture after continuous using 7 d. Density Functional Theory (DFT) calculations demonstrated that Co-NC900 can efficiently activate PMS through unique ping-pong mechanism (C-N bond breaking and re-forming process), and further degrade ECs. This study presents a novel approach for the development of efficient and stable metal-based catalysts for the removal of ECs from water.
研究领域:
环境科学
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化学工程
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材料科学
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水处理
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Cen Zhang,Rui Wang,Guowen Zhang,Deming Gong
Quercetin, one of the most abundant flavonoid in the daily diet, was found to reversibly inhibit the generation of uric acid and superoxide radicals (O 2 − )catalyzed by xanthine oxidase (XOD) in a mixed-type manner with IC 50 values of (2.74 ± 0.04) × 10 −6 and (2.90 ± 0.03) × 10 −6 mol L −1 , respectively, and the inhibition of quercetin on O 2 − generation may be ascribed to the reduced form of XOD by a ping-pong mechanism. XOD had one high affinity binding site for quercetin with a binding constant of 4.28 × 10 4 L mol −1 at 298 K, and the binding process was predominately driven by van der Waals forces and hydrogen bonds on account of the negative enthalpy and entropy changes. Moreover, molecular docking confirmed that the binding site for quercetin located in the isoalloxazine ring of the flavin adenine dinucleotide (FAD) domain of XOD, then the diffusion of O 2 − out of the FAD site was blocked in favor of another electron transferred from FADH 2 to O 2 − to form hydrogen peroxide (H 2 O 2 ). This study may clarify the role of quercetin on inhibiting XOD catalysis and provide a potential nutritional supplement for preventing gout and peroxidative damage.
研究领域:
生物化学
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药理学
·
营养科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2016
·
IF 3.182
Cen Zhang,Guowen Zhang,Junhui Pan,Deming Gong
Galangin is a natural flavonol isolated from plants with potent biological activities. Galangin was found to significantly inhibit xanthine oxidase (XOD) activity in a competitive manner with the generation of superoxide radical (O 2 − ) in the enzyme catalysis, but galangin showed insignificant scavenging activity on 1,1-diphenyl-2-picryhydrazyl (DPPH) and O 2 – radicals. These results demonstrated that inhibition of O 2 – radical generation by galangin may be due to the competitive inhibition of uric acid formation by a ping-pong mechanism. XOD had one high affinity binding site for galangin with a binding constant of 3.60 × 10 4 L mol − 1 at 298 K. Hydrogen bond and hydrophobic interaction dominated the binding process on account of the negative enthalpy and positive entropy changes. The binding of galangin to XOD induced an increase in α-helix and random coil contents and a decrease in β-sheet and β-turn contents of XOD. Further molecular docking study validated that galangin can competitively bind to the site in the molybdenum atomic (Mo) domain, occupying the catalytic center to avoid the entrance of the substrate xanthine, resulting in the inhibition of XOD activity. These findings have provided new insights into the two-substrate kinetics of galangin on XOD and useful information for functional research of galangin in the treatment of gout and oxidative damage.
研究领域:
药理学
·
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2018
·
IF 4.244
Menglu Li,Juan Yang,Yining Ou,Ying Shi,Li Liu,Chaoqun Sun,Huzhi Zheng,Yijuan Long
The peroxidase-like activity of 2',7'-difluorofluorescein (DFF), was investigated using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate in the presence of H 2 O 2 . DFF could catalyze oxidization of TMB by H 2 O 2 to produce a blue colored oxidation product. Effect of various reaction conditions, such as pH, temperature, H 2 O 2 concentration and reaction time on the catalytic activity of DFF was studied. The peroxidase-like activity of DFF was found to follow Michaelis–Menten kinetics, and its catalysis accorded with ping-pong mechanism. The calculated kinetic parameters (K cat ) of DFF catalysis showed higher peroxidase-like activity than fluorescein and 2′,7′-dichlorofluorescein (DCF). According to the radical capture and electron spin resonance (ESR) spectroscopy results, we confirmed that hydroxyl radical (•OH) is the active specie of catalytic process. It is known that the oxidation of galactose by galactose oxidase (GAOx) enzyme leads to the formation of H 2 O 2 , the H 2 O 2 released in this reaction was consequently quantified using DFF as peroxides mimics and TMB as the chromogen. Thus, a combination of above two reactions was exploited to establish a method for galactose detection. Under the optimum conditions, the linear range of this method was from 10 μM to 20 mM with the detection limit down to 3 μM. Moreover, the developed method was applied to detect galactose in urine samples. Our work will facilitate the utilization of DFF intrinsic peroxidase-like activity in medical diagnostics and biotechnology.
研究领域:
生物化学
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分析化学
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医学诊断
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
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