ENZYME AND MICROBIAL TECHNOLOGY
·
2021
·
IF 3.493
Zhiji Chen,Feiying Mao,Haoteng Zheng,Qinjie Xiao,Zhihao Ding,Anming Wang,Xiaolin Pei
Aromatic nitriles are important structural motifs that frequently existed in pharmaceutical drugs. Due to the convenient synthesis of aldoximes from aldehydes, the dehydration of aldoximes to corresponding nitriles by aldoxime dehydratases (Oxds) is considered as a safe and robust enzymatic production route. Although the Oxd genes are widely distributed in microbial kingdom, so far less than ten Oxds were expressed and further characterized. In this study, we found 26 predicted putative Oxd genes from the GenBank database using a genome mining strategy. The Oxd gene from Pseudomonas putida F1 was cloned and functionally expressed in Escherichia coli BL21 (DE3). The amino acid sequence of OxdF1 shows high identities of 33∼85 % to other characterized Oxds, and contained a ferrous heme as the catalytic site. The optimum reaction pH and temperature of recombinant OxdF1 were 7.0 and 35 °C, respectively. OxdF1 was stable in pH 7.0 potassium phosphate buffer at 30 °C, and its half-life was approximately 3.8 h. OxdF1 can efficiently dehydrate aromatic and heterocyclic aldoximes to nitriles, such as 2-bromobenzaldoxime, 2-chloro-6-fluorobenzaldoxime, thiophene-2-carboxaldoxime, and pyridine-3-aldoxime. Therefore, the recombinant OxdF1 shows a potential application in the cyanide-free synthesis of aromatic nitriles.
研究领域:
生物化学
·
酶学
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药物化学
·
生物技术
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DOI
PubMed
高影响因子
TALANTA
·
2026
·
IF 6.7
Wenteng Qiao,Caihong Yin,Boyuan Chen,Yue Zhai,Xiuling Song
Total antioxidant capacity represents a critical parameter for assessing food quality and freshness, while conventional detection methodologies are often constrained by operational intricacy or insufficient efficiency. Herein, we developed a rapid and user-friendly colorimetric sensing platform based on manganese oxide (MnOx) nanozymes for the quantification of antioxidants in fruit juice samples. MnOx nanozymes can efficiently catalyze the oxidation of the colorless substrate 3,3′,5,5′-tetramethylbenzidine, yielding a blue reaction product; however, the presence of antioxidants significantly suppresses this catalytic activity, inducing concentration-dependent color shifts in the reaction system. After systematic optimization of key reaction parameters (e.g., nanozyme concentration, TMB dosage, reaction temperature, and incubation time), the proposed platform achieved a detection limit of 1.79 μM, with a naked - eye visual detection limit of 5 μM and a total detection time of <10 min. Practical validation in real fruit juice samples verified the accuracy of the developed method for antioxidant quantification, as evidenced by recovery rates of 88.76%–109.10% and RSDs of all below 3.44%.This work introduces a novel, efficient, and stable approach for the rapid monitoring of TAC in food products, exhibiting considerable potential for food quality control and safety assessment.
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Mengran Xu,Yi Hu,Ya Xiao,Yuanyuan Zhang,Kaili Sun,Ting Wu,Na Lv,Wenshen Wang,Weiping Ding,Fenfen Li,Bensheng Qiu,Jiabin Li
Nanozymes that mimic peroxidase (POD) activity can convert H2O2 into bactericidal free radicals, which is referred to as chemodynamic therapy (CDT). High glutathione (GSH) levels in the infectious tissue severely limit the performance of CDT. Herein, we report a near-infrared-controlled antibacterial nanoplatform that is based on encapsulating tungsten sulfide quantum dots (WS2QDs) and the antibiotic vancomycin in a thermal-sensitive liposome. The system exploits the photothermal sensitivity of the WS2QDs to achieve selective liposome rupture for the targeted drug delivery. We determined that WS2QDs show a strong POD-like activity under physiological conditions and the oxidase-like activity, which can oxidate GSH to further improve the CDT efficacy. Moreover, we found that increased temperature promotes multiple enzyme-mimicking activities of WS2QDs. This platform exerts antibacterial effects against Gram-positive Mu50 (a vancomycin-intermediate Staphylococcus aureus reference strain) and Gram-negative Escherichia coli and disrupts biofilms for improved penetration of therapeutic agents inside biofilms. In vivo studies with mice bearing Mu50-caused skin abscess revealed that this platform confers potent antibacterial activity without obvious toxicity. Accordingly, our work illustrates that the photothermal and nanozyme properties of WS2QDs can be deployed alongside a conventional therapeutic to achieve synergistic chemodynamic/photothermal/pharmaco therapy for powerful antibacterial effects.
研究领域:
纳米医学
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材料科学
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生物医学工程
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微生物学
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治疗学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2022
·
IF 5.999
Ruigeng Yang,Yueru Wei,Mengyang Zhao,Mengxiao Shi,Yongxing Zhao,Pengchao Sun
The abuse of antibiotics has led to the emergence of multidrug-resistant bacterial strains worldwide, which greatly threatens human health. In the present work, we developed single-atom catalysts (SACs) with atomically dispersed Fe as catalytic sites (Fe-SACs) to combat multidrug-resistant bacteria by elevating cellular reactive oxygen species (ROS). Our intensive studies confirmed that Fe-SACs were successfully prepared and exhibited excellent catalase (CAT)-, oxidase (OXD)-, and peroxidase (POD)-like activities. To enhance water dispersibility, biosafety and the interactions between the nanodrugs and gram-positive bacteria, phenylboronic acid group-functionalized carboxylated chitosan (CCS-PBA) was coated on the surface of Fe-SACs to yield [email protected] for in vitro and in vivo studies. The synergistic catalytic activity and photothermal activity of [email protected] effectively overcame multidrug-resistant bacterial strains ( MRSA) in vitro and significantly accelerated wound healing in vivo , suggesting the great potential of SACs to overcome infectious disease caused by multidrug-resistant bacteria.
研究领域:
纳米技术
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细菌学
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材料科学
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生物医学工程
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药学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2022
·Vol. 189
·期 8
·1-10
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IF 6.408
Tan Bing,Zhang Shasha,Wang Kemeng,Yan Yingli,Chu Zhili,Wang Qiwen,Li Xiang,Zhu Guifen,Fan Jing,Zhao Huimin
A moisture-resistant and green cyclodextrin metal–organic framework (CD-MOF) nanosheet has been prepared via an one-pot antisolvent synthesis procedure. After the treatment of in situ chemical cross-linkage, the two-dimensional (2D) cross-linked CD-MOF exhibited both peroxidase (POD) and oxidase (OXD) enzymatic activities, as well as hydrolytic stability. On the basis of its POD mimics function, the proof-of-concept biosensors were constructed to realize the colorimetric detection for H 2 O 2 and glucose, respectively. In vitro cytotoxicity experiments showed that the 2D cross-linked CD-MOF nanozymes still maintained excellent biocompatibility even at a concentration reaching up to several mg/mL. The in situ colorimetric detection of H 2 O 2 secreted by HepG2 cells further confirmed its promising biocompatibility, showing its great promises as label-free colorimetric probe in early cancer detection and pathological process monitoring. Graphical abstract
研究领域:
材料科学
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纳米技术
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生物化学
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分析化学
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生物医学工程
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癌症研究
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）