ACS Nano
·
2024
·
IF 15.8
Xu Li,Wenlong Tan,Jinsong Fan,Kun Li
Although the past decade has witnessed a rapid development of oxidoreductase-mimicking nanozymes, the mimicry of cofactors that play key roles in mediating electron and proton transfer remains limited. This study explores how surface Au–H species conjugated to Au nanoparticles (NPs) that imitate formate dehydrogenase (FDH) can serve as cofactors, analogous to NADH in natural enzymes, offering diverse possibilities for FDH-mimicking Au nanozymes to mimic various enzymes. Once O2 is present, Au–H species assist Au NPs to complete the on-demand H2O2 generation for cascade reactions. Alternatively, when oxidizing organic molecules are introduced as substrates, Au–H species confer nitro reductase- and aldehyde reductase-like activities on Au NPs under anaerobic conditions. Furthermore, similar to the dehydrogenase–NADH complex, Au NPs possessing Au–H species are gifted with esterase-like activity for ester hydrolysis. By revealing that Au–H species are prosthetic groups for FDH-mimicking Au nanozymes, this work may inspire explorations into future self-generated cofactor mimics for nanozymes, thereby circumventing the need for exogenous cofactors.
研究领域:
催化
·
生物化学
·
纳米技术
·
酶学
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DOI
PubMed
高影响因子
Journal of Pharmaceutical Analysis
·
2024
·
IF 6.1
Yang Xu,Shujing Lv,Xiang Li,Chuanjia Zhai,Yulian Shi,Xuejiao Li,Zhiyang Feng,Gan Luo,Ying Wang,Xiaoyan Gao
Sennoside A (SA), a typical prodrug, exerts its laxative effect only after its transformation into rheinanthrone catalyzed by gut microbial hydrolases and reductases. Hydrolases have been identified, but reductases remain unknown. By linking a photoreactive group to the SA scaffold, we synthesized a photoaffinity probe to covalently label SA reductases and identified SA reductases using activity-based protein profiling. From lysates of an active strain, Bifidobacterium pseudocatenulatum ( B . pseudocatenulatum ), 397 proteins were enriched and subsequently identified using mass spectrometry. Among these proteins, chromate reductase/nicotinamide adenine dinucleotide phosphate (NADPH)-dependent flavin mononucleotide (FMN) reductase/oxygen-insensitive NADPH nitroreductase (nfrA) was identified as a potent SA reductase through further bioinformatic analysis and Uniprot database screening. We also determined that recombinant nfrA could reduce SA. Our study contributes to further illuminating mechanisms of SA transformation to rheinanthrone and simultaneously offers an effective method to identify gut bacterial reductases.
研究领域:
微生物学
·
药理学
·
蛋白质组学
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Guochao Xu,Yaping Zhang,Yue Wang,Ye Ni
In this work, genome hunting strategy was adopted in screening for reductases from Candida glabrata . A total of 37 putative reductases were successfully expressed in E. coli BL21(DE3). A substrate library containing 32 substrates was established for characterization of each reductase by average specific activity and Shannon-Wiener index. Among them, Cg26 was identified with the highest efficiency and wider substrate spectrum in the reduction of prochiral ketones, with average activity and Shannon-Wiener index of 8.95 U·mg −1 and 2.82. Cg26 is a member of ‘extended’ short chain dehydrogenase/reductase superfamily. Ni 2+ could improve its activity. As much as 150 g·L −1 ethyl 2-oxo-4-phenylbutyrate could be completely converted by 10 g·L −1 Cg26. This study provides evidence for this newly identified Cg26 in the preparation of chiral secondary alcohols.
研究领域:
生物化学
·
酶工程
·
合成生物学
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DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Qian Chen,Tingting Li,Mengyao Gui,Shufeng Liu,Maosheng Zheng,Jinren Ni
Anaerobic denitrification has been proved to be negatively affected by ZnO nanomaterials (NPs), but little is known about how ZnO NPs affects aerobic denitrification. In this study, inhibition of ZnO NPs to an aerobic denitrifier, Pseudomonas stutzeri PCN-1, was firstly reported. The results showed total nitrogen removal efficiency was decreased from 100% to 1.70% with the increase of ZnO NPs from 1 to 128 mg/L. The presence of ZnO NPs caused significant inhibition of gene expressions and catalytic activities of nitrate reductase and nitrite reductase, which finally led to delayed nitrate reduction and high nitrite accumulation. Further studies revealed that the deposition of nanoparticles on the bacterial surface caused by electrostatic forces and the generation of reactive oxygen species (ROS) were responsible for the cytotoxicity of ZnO NPs, where ROS played a more important role. These results were of significance to evaluating the potential ecological toxicity and risks of nanomaterials.
研究领域:
环境科学
·
微生物学
·
纳米技术
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DOI
PubMed
高影响因子
BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2021
·Vol. 69
·期 4
·1428-1437
·
IF 2.431
Di Liu,Linbo Gou,Yajun Bai,Tai-Ping Fan,Xiaohui Zheng,Yujie Cai
In this study, the 3-quinuclidinone reductase from Agrobacterium tumefaciens (AtQR) was modified by site-directed mutagenesis. And we further obtained a saturation mutant library in which the residue 197 was mutated. A single-point mutation converted the wild enzyme that originally had no catalytic activity in reduction of ethyl 4-chloroacetoacetate (COBE) into an enzyme with catalytic activity. The results of enzyme activity assays showed that the seven variants could asymmetrically reduce COBE to ethyl ( S )-4-chloro-3-hydroxybutyrate (( S )-CHBE) with NADH as coenzyme. In the library, the variant E197N showed higher catalytic efficiency than others. The E197N was optimally active at pH 6.0 and 40°C, and the catalytic efficiency ( k cat / K m ) for COBE was 51.36 s –1 ·mM –1 . This study showed that the substrate specificity of AtQR could be changed through site-directed mutagenesis at the residue 197.
研究领域:
生物化学
·
酶学
·
生物催化
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DOI
PubMed
高影响因子
ChemSusChem
·
2025
·
IF 6.6
Zhenyu Zhai,Yunjie Li,Zhilei Li,Jingting Wang,Yuan Li,Yi-Heng P. Job Zhang
Graphical Formaldehyde poses a significant threat to human health. We developed an enzymatic technique for the cleanup of formaldehyde in aqueous solutions. This technique utilized an enzyme cocktail, which catalyzed the reaction of formaldehyde and ambient dioxygen into carbon dioxide and water, with degradation ratios of up to 100 %. Numerous methods have been developed to address gaseous formaldehyde pollution, but most of them cannot be applied directly to eliminate the pollution of formaldehyde in aqueous solutions. Formaldehyde in aqueous solutions can be leached from formaldehyde-containing solid materials (e. g., food, wood, clothes, resins) and absorbed from gaseous formaldehyde by water. Here we developed an enzymatic cleanup technique — the reconstitution of an enzyme cocktail consisting of three coenzyme-free oxidoreductases (i. e., formaldehyde dismutase, methanol oxidase, and formate oxidase) and catalase for the complete oxidation of formaldehyde. This enzyme cocktail catalyzed the reaction of formaldehyde and ambient dioxygen into carbon dioxide (CO 2 ) and water, which was demonstrated by the stable isotope tracer technique. Significant levels of formaldehyde were detected from aqueous solutions leached from the squid, pomfret, fabric, and curtain in the market. When this enzyme cocktail was applied to treat the leachates of contaminated samples above, formaldehyde was eliminated with degradation ratios of up to 100 %. This enzymatic cleanup technique, featuring excellent biosafety (for example, degradable catalysts and non-immunogenicity), independence from light, high degradation ratios, and no special equipment required, could be widely used to treat contaminated food, drinking water, and formaldehyde-containing leachate.
研究领域:
环境科学
·
生物化学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Zeyu Wang,Cong Chen,Huan Liu,Dzmitry Hrynshpan,Tatsiana Savitskaya,Jianmeng Chen,Jun Chen
Multi-walled carbon nanotubes (MWCNTs) promote biodegradation in water treatment , but the effect of MWCNT on denitrification under aerobic conditions is still unclear. This investigation focused on the denitrification performance of MWCNT and its toxic effects on Alcaligenes sp. TB which showed that 30 mg/L MWCNTs increased NO 3 - removal efficiency from 84% to 100% and decreased the NO 2 - and N 2 O accumulation rates by 36% and 17.5%, respectively. Nitrite reductase and nitrous oxide reductase activities were further increased by 19.5% and 7.5%, respectively. The mechanism demonstrated that electron generation (NADH yield) and electron transportation system activity increased by 14.5% and 104%, respectively. Cell membrane analysis found that MWCNT caused an increase in polyunsaturated fatty acids, which had positive effects on electron transportation and membrane fluidity at a low concentration of 96 mg/kg but caused membrane lipid peroxidation and impaired membrane integrity at a high concentration of 115 mg/L. These findings confirmed that MWCNT affects the activity of Alcaligenes sp. TB and consequently enhances denitrification performance.
研究领域:
环境科学
·
生物技术
·
水处理
·
微生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Zhe Dou,Pei-Ru Hu,Lin-Lin Song,Yi-Cheng Wang,Hao-Nan Tang,Zhen-Qi Weng,Ya-Jun Wang,Yuan-Qiang Cai
Carbonyl reductases (CRs) are promising biological macromolecules for the asymmetric synthesis of chiral secondary alcohols. A novel CR was evolved for efficient conversion of d -xylose into anti-aging ( S )-Pro-Xylane. Through extensive gene mining, an active carbonyl reductase Zm CR was identified from Zygofabospora marxiana with high reductive activity towards d -xylose-derived 1-C-(β- d -xylopyranosyl)-acetone (XPSA) and in situ cofactor regeneration capability. Using a three-round of concise engineering strategy, a hextuple mutant C85V/V128C/S129A/V161S/Y166H/T217A (M6) was identified from merely 157 mutants with specific activity of 46.00 U·mg −1 , about 306 folds of WT. The Shannon-Wiener index of M6 was 2.21, much higher than WT, indicating its extended substrate scope. M6 could efficiently catalyze the asymmetric reduction of 190 g·L −1 XPSA into ( S )-XPSP. The k cat / K M XPSA of M6 was 203.84 s −1 ·mM −1 , about 910 folds of WT. More non-bonded interactions were monitored in M6, contributing to the stabilization of reactive catalytic conformation. This study provides a promising biocatalyst for the chemoenzymatic synthesis of value-added anti-aging ( S )-Pro-Xylane from lignocellulosic d -xylose.
研究领域:
生物化学
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酶工程
·
合成生物学
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DOI
PubMed
高影响因子
MOLECULAR BIOTECHNOLOGY
·
2016
·Vol. 58
·期 6
·428-440
·
IF 1.752
Yang Yuanyuan,Lin Jinping,Wei Dongzhi
A NADPH-dependent and FMN-containing nitroreductase (Gox0834) from Gluconobacter oxydans was cloned and heterogeneously expressed in Escherichia coli . The purified enzyme existed as a dimer with an apparent molecular mass of about 31.4 kDa. The enzyme displayed broad substrate specificity and reduced a variety of mononitrated, polynitrated, and polycyclic nitroaromatic compounds to the corresponding amino products. The highest activity was observed for the reduction of CB1954 (5-(1-aziridinyl)-2,4-dinitrobenzamide). The enzyme kinetics analysis showed that Gox0834 had relatively low K
m
(54 ± 11 μM) but high k
cat / K
m
value (0.020 s −1 /μM) for CB1954 when compared with known nitroreductases. Nitrobenzene and 2,4,6-trinitrotoluene (TNT) were preferred substrates for this enzyme with specific activity of 11.0 and 8.9 μmol/min/mg, respectively. Gox0834 exhibited a broad temperature optimum of 40–60 °C for the reduction of CB1954 with a pH optimum between 7.5 and 8.5. The purified enzyme was very stable below 37 °C over a broad pH range of 6.0–10.0. These characteristics suggest that the nitroreductase Gox0834 may be a possible candidate for catalyzing prodrug activation, bioremediation, or biocatalytic processes.
研究领域:
微生物学
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酶学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2016
·
IF 2.189
Min Li,Zheng Zhou,Zhi-Jun Zhang,Hui-Lei Yu,Jian-He Xu
Nitrile reductase is a newly discovered enzyme class that can catalyze the reduction of nitriles directly to amines, a very important reaction in synthetic organic chemistry. However, little progress has been made towards the application of this biocatalysis reaction for organic synthesis since the initial discovery of nitrile reductase for over ten years. One of the potential reasons may be due to the lack of structural information and biochemical properties, in addition to its inherent narrow substrate scope. Meanwhile, the highly conserved active site residues make it a great challenge to widen the substrate spectrum of nitrile reductase by means of protein engineering approaches. To explore more nitrile reductases with different characteristics ( e.g . specific activity, thermostability, etc ) for potential synthetic applications, a new nitrile reductase, designated as Pc NRed, was discovered from the genome of Pectobacterium carotovorum , with a moderate specific activity of 366 U/g protein towards its natural substrate, preQ 0 . The Pc NRed was subsequently overexpressed in Escherichia coli BL21 (DE3), purified to homogeneity and then its biochemical properties were examined. The optimal reaction temperature and pH were determined to be 40 °C and 7.4, respectively. The thermal deactivation process of Pc NRed obeys first-order kinetics, with half-lives of 47.2, 13.6 and 3.9 h measured at 30, 40, and 50 °C, respectively. The kinetic constants were also determined with respect to both of the substrates NADPH and preQ 0 , giving k cat of 0.025 s −1 and 0.024 s −1 , and K M of 0.229 mM and <0.25 μM. To shed some light on the structural information of Pc NRed, a homology model was built and compared with its counterparts, which is helpful for further engineering of this novel but less-elucidated enzymes.
研究领域:
生物化学
·
酶工程
·
合成生物学
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DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1086
·
IF 4.501
Byu Ri Sim,Jie Gu,Yvette Ley,Shenggan Luo,Yihan Liu,Qin Chen,Yao Nie,Yi-Lei Zhao
Candida parapsilosiscarbonyl reductases (CpRCR) have been widely used for the reductive conversion of ketone precursors and chiral alcohol products in pharmaceutical industries. The enzymatic enantioselectivity is believed to be related to the shape complementation between the cavities in the enzymes and the substitutions of the ketone substrates. In this work, we reported an unexpected enantioselectivity in the enzyme reductions of dihydrofuran-3(2H)-one (DHF) to (S)-tetrahydrofuran-3-ol (DHF-ol, enantiomeric excess: 96.4%), while dihydrothiophen-3(2H)-one substrate (DHT) was unproductive under the same experimental conditions. To rationalize the exclusiveS-configuration and the specific reactivity ofDHF, we carried out molecular dynamics simulations for the reacting complexations ofDHFwithCpRCR, andDHTwithCpRCR. Our calculations indicate thatDHFpreferentially binds to the small cavity near L119, F285, and W286, while the large cavity near theα1helix was mainly occupied by solvent water molecules. Moreover, the pre-reaction state analysis suggests that thepro-Sconformations were more abundant than thepro-R, in particular forDHF. This suggests that the non-polar interaction of substrate C4-C5 methylene contacting the hydrophobic side-chains of L119-F285-W286, and the polar interaction of funanyl oxygen exposing the solvent environment play important roles in the enantioselectivity and reactivity. The phylogenetic tree ofCpRCR homologues implies that a variety of amino acid combinations at positions 285 and 286 were available and thereby potentially useful for redesigning enantioselective reductions of 5-membered-ring heterocyclic ketones.Keywords:carbonyl reductases;enantioselectivity;heterocyclic ketone;molecular modelling
研究领域:
生物化学
·
酶工程
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产品关联
DOI
高影响因子
REDOX REPORT
·
2024
·
IF 5.2
Xiaowan Chen,Yan Ma,Ziming Yang,Dingjie Shen,Xia Li,Maowei Ni,Xiaoling Xu,Wei Chen
Glutathione reductase (GR), one of the most important antioxidant enzymes in maintaining intracellular redox homeostasis, has become a novel target to suppress cancer cell growth and metastasis. In this work, we evaluated a series of naphthoquinones (NQs) as potential GR inhibitors and elucidated the mechanism of inhibition. NQ-6, one of the most potent compounds among this series, inhibited GR in vitro and in vivo and was identified as a competitive and irreversible inhibitor. The Ki and kinact values of NQ-6 were determined to be 17.30 ± 3.63 μM and 0.0136 ± 0.0005 min-1, respectively. The tandem mass spectrometric analysis revealed that the two substrate binding sites Cys61 and Cys66 of yeast GR were modified simultaneously through arylation or only Cys66 was covalently modified by NQ-6. Intracellular reactive oxygen species, collapsing of mitochondrial membrane potential and protein S-glutathionylation elevation were induced by NQ-6. NQs can be valuable compounds in GR inhibition and oxidative stress-related research.
研究领域:
药理学
·
生物化学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
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