Molecular Catalysis
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2022
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IF 5.089
Xiaoxiang Hu,Huaxiang Deng,Yajun Bai,Tai-Ping Fan,Xiaohui Zheng,Yujie Cai
Arabidopsis has attracted increasing attention to biotechnology as a model plant. Among, many of studies have focused on monoterpenoids metabolism. Borneol is a typical representative of monoterpenoids and widely applied in fragrances and pharmaceuticals. And (+)-camphor also is also attracting more and more interest in the field of pharmaceutical. However, the enzyme involved the conversion of borneol and camphor in Arabidopsis is still unknown. In this study, a borneol dehydrogenase (BDH) from Arabidopsis lyrate was overexpressed in Escherichia coli BL21 (DE3). The optimum pH for reduction and oxidation were 7.5 and 9.0, respectively, and the optimum temperature was 45 ℃. The specific activity of reduction reaction for (-)-camphor and (+)-camphor were 1.09 and 0.76 U·mg −1 which were the highest so far. The AlBDH coupled with glucose dehydrogenase (GDH) of coenzyme regeneration could efficiently convert rac -camphor, yielding 4.64 mM rac -borneol within 3.5 h with a conversion of 92.8%. A single point mutation L205F could successfully be used for enzymatic resolution of 2 mM rac -camphor, yielding 95.9% of (+)-camphor with an ee s of > 99%. It also could respectively reduce (+)-camphor and (-)-camphor to optically pure (+)-borneol and (+)-isoborneol. The study of the enzymatic properties of AlBDH lay an important foundation for further studies on the conversion of borneol and camphor in Arabidopsis and provide potential industrial application value for the optically pure enantiomers borneol sustainable synthesis in the future.
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AQUACULTURE
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2022
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IF 5.135
Linhan Li,Tao Zhang,Gengrong Zhang,Guoqing Zhou,Fei Yang,Erlong Wang,Tianqiang Liu,Gaoxue Wang
Micropterus salmoides rhabdovirus (MSRV) seriously threats largemouth bass farming in China. Vaccine is a widely-used way to protect against virus infection. However, traditional intramuscular injection is inconvenient, time-consuming, and hard to applicate universally. We employed the naturally biodegradable bacterial nanocellulose (BNC) as effective virus antigen carriers for bath vaccination and improving the largemouth bass immune response. In this study, 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation of bacterial cellulose (BC) was applied to produce carboxylated BC, which was validated by Fourier transform infrared spectroscopy (FTIR) and elementary analysis. Followed by a controlled sulfuric acid hydrolysis reaction to form carboxylated bacterial nanocellulose (BNC-COOH) with an average size of about 350 nm. Amination reaction was conducted via conjugating the amine groups in MSRV glycoproteins (G) with the carboxyl groups in the BNC-COOH. The prepared bacterial nanocellulose loaded glycoprotein complex (BNCs-G) was used to vaccine largemouth bass via bath immunization. The protective effects were assessed by analyzing MSRV G proteins-specific serum antibody levels and the expression of four immune-related genes ( IgM , IL-12 , TCR , TNF- α, and CD4 ). Results showed that serum antibody levels and the expression of immune-related genes were significantly increased for BNCs-G bath-vaccinated groups (40 mg L −1 ), compared with PBS and the naked G protein groups. After bath immunization for four weeks, fish were challenged with a lethal dose of MSRV. The survival rates for control group (PBS), BNCs group (40 mg L −1 ), the naked G protein groups (40 mg L −1 ) and three BNCs-G groups (10 mg L −1 , 20 mg L −1 and 40 mg L −1 ) were 0%, 0%, 30.0%, 16.7%, 46.7% and 66.7%, respectively. These results indicated that BNCs could be a plausible candidate for the vaccine carrier system, and the BNC loaded glycoprotein showed good immunogenicity.
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PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
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2022
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IF 4.966
Jiang Zhu,Jing Feng,Kai Tian,Chong Li,Mei Li,Xinghui QIU
The house fly ( Musca domestica L.) (Diptera: Muscidae) is a global vector that can transmit >250 human and animal diseases. The control of house flies has heavily relied on the application of various chemical insecticides . The carbamate insecticide propoxur has been widely used for the control of house flies, and resistance to propoxur has been documented in many house fly populations worldwide. Previous studies have identified several propoxur resistance-conferring mutations in the target protein acetylcholinesterase ; however, the molecular basis for metabolic resistance to propoxur remains unknown. In this study, we investigated the involvement of CYP6G4, a cytochrome P450 overexpressed in many insecticide resistant populations of Musca domestica , in propoxur metabolism and resistance by using combined approaches of recombinant protein-based insecticide metabolism and the Drosophila GAL4/UAS transgenic system. The recombinant CYP6G4 and its redox partners (NADPH-dependent cytochrome P450 reductase and cytochrome b 5) were functionally expressed in Escherichia coli . Metabolism experiments showed that CYP6G4 was able to transform propoxur with a turnover rate of around 0.79 min −1 . Six metabolites were putatively identified, suggesting that CYP6G4 could metabolize propoxur via hydroxylation , O-depropylation and N -demethylation. Moreover, bioassay results showed that ectopic overexpression of CYP6G4 in fruit flies significantly increased their tolerance to propoxur. Our in vivo and in vitro data convincingly demonstrate that CYP6G4 contributes to propoxur metabolism and resistance.
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高影响因子
Frontiers in Bioengineering and Biotechnology
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2022
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IF 6.064
Wang Jing,Chen Qiaoyu,Wang Xin,Chen Kequan,Ouyang Pingkai
D-1,2,4-Butanetriol (BT) has attracted much attention for its various applications in energetic materials and the pharmaceutical industry. Here, a synthetic pathway for the biosynthesis of BT from d-arabinose was constructed and optimized in Escherichia coli. First, E. coli Trans1-T1 was selected for the synthesis of BT. Considering the different performance of the enzymes from different organisms when expressed in E. coli, the synthetic pathway was optimized. After screening two d-arabinose dehydrogenases (ARAs), two d-arabinonate dehydratases (ADs), four 2-keto acid decarboxylases (ADXs), and three aldehyde reductases (ALRs), ADG from Burkholderia sp., AraD from Sulfolobus solfataricus, KivD from Lactococcus lactis IFPL730, and AdhP from E. coli were selected for the bio-production of BT. After 48 h of catalysis, 0.88 g/L BT was produced by the recombinant strain BT5. Once the enzymes were selected for the pathway, metabolic engineering strategy was conducted for further improvement. The final strain BT5ΔyiaEΔycdWΔyagE produced 1.13 g/L BT after catalyzing for 48 h. Finally, the fermentation conditions and characteristics of BT5ΔyiaEΔycdWΔyagE were also evaluated, and then 2.24 g/L BT was obtained after 48 h of catalysis under the optimized conditions. Our work was the first report on the biosynthesis of BT from d-arabinose which provided a potential for the large-scale production of d-glucose-based BT.
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ENZYME AND MICROBIAL TECHNOLOGY
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2022
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IF 3.705
Hong-Ru Zhao,Bing-Mei Su,Yi-Bing Shi,Juan Lin
Ethyl 3-hydroxy-3-phenylpropionate (EHPP), ( R )-EHPP or ( S )-EHPP, is an important chiral intermediate for pharmaceuticals. Its synthesis from ethyl benzoyl acetate (EBA) by alcohol dehydrogenase is regarded as a green method. However, scarcely any alcohol dehydrogenase has been reported competent in asymmetric synthesis of chiral EHPP at high EBA loading. Present study developed two robust and efficient bio-catalysts Mu-S2 and Mu-R4 for preparation of ( S )-EHPP and ( R )-EHPP respectively by rational design of alcohol dehydrogenase PcSDR from Pedobacter chitinilyticus based on molecular dynamics (MD) simulation analysis. BtGDH, a glucose dehydrogenase from Bacillus toyonensis catalyzing the oxidation of glucose for cofactor regeneration, was co-expressed with the screened mutants to form enzyme systems Mu-S2-BtGDH and Mu-R4-BtGDH. After reaction condition optimization, Mu-S2-BtGDH and Mu-R4-BtGDH were efficient in the synthesis of ( S )-EHPP (94% conv. and 99% e.e.) and ( R )-EHPP (99% conv. and 98% e.e. ) respectively in 100 mL scale under 500 mM of EBA loading in 10 h following a substrate continuous feeding mode. After purifying, the isolated yield for each EHPP enantiomer is > 93%. This work not only provides potential biocatalysts for the industrial production of ( R )-EHPP and ( S )-EHPP, but also enriches the constructure-function relationship of alcohol dehydrogenases.
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RSC Advances
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2022
·Vol. 12
·期 18
·11090-11099
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IF 4.036
Jiacheng Shi,Rui Shu,Xiuyuan Shi,Yunfei Li,Jiangge Li,Yi Deng,Weizhong Yang
Drug-free antibacterial strategies are of great significance for pathogenic bacterial infection treatment in clinical practice. Phototherapy with antibacterial function plays a vital role in mainstream germicidal research. However, phototherapy could lead to residual heat and excess reactive oxygen species (ROS), which are the main side-effects during antibacterial treatment. Unique CoFe2O4/MXene (CM) nanoenzymes, which were fabricated with electrostatic interactions, have been designed to conquer those challenges caused by side-effects of phototherapy in our research. The CM nanoenzymes possess many promising properties including photothermal and photodynamic induced phototherapy and mimic peroxidase (POD), glutathione oxidase (GSHOx), and catalase (CAT). Upon treatment with near-infrared (NIR) light, CM nanoenzymes can create a local high-temperature circumstance as well as raise bacterial membrane permeability. Furthermore, the photodynamic process and multi-enzyme-mimicking activities of CM enzymes boost the interbacterial ROS level. Herein, bacteria can hardly survive in synergistic phototherapy and multi-enzyme-mimicking catalytic therapy in vitro and in vivo. Meanwhile, the CM nanoenzymes exhibit excellent biocompatibility in vitro and in vivo. Overall, this research establishes a strong foundation for effectively employing nanoenzymes, leading to a new way to cure bacterial infections.
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Science Advances
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2022
·Vol. 8
·期 18
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IF 14.957
Xinyu Wang,Jicong Zhang,Ke Li,Bolin An,Yanyi Wang,Chao Zhong
There is an increasing trend of combining living cells with inorganic semiconductors to construct semi-artificial photosynthesis systems. Creating a robust and benign bio-abiotic interface is key to the success of such solar-to-chemical conversions but often faces a variety of challenges, including biocompatibility and the susceptibility of cell membrane to high-energy damage arising from direct interfacial contact. Here, we report living mineralized biofilms as an ultrastable and biocompatible bio-abiotic interface to implement single enzyme to whole-cell photocatalytic applications. These photocatalyst-mineralized biofilms exhibited efficient photoelectrical responses and were further exploited for diverse photocatalytic reaction systems including a whole-cell photocatalytic CO2 reduction system enabled by the same biofilm-producing strain. Segregated from the extracellularly mineralized semiconductors, the bacteria remained alive even after 5 cycles of photocatalytic NADH regeneration reactions, and the biofilms could be easily regenerated. Our work thus demonstrates the construction of biocompatible interfaces using biofilm matrices and establishes proof of concept for future sustainable photocatalytic applications.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Ling Zheng,Zilong Guo,Yinxiao Xu,Benwei Zhu,Zhong Yao
Pectate lyase (ErPL2) from Echinicola rosea JL3085 showed maximal activity at 45 °C and pH 9.0 with 0.6 mM CaCl 2 . The K m and V max values of ErPL2 for polygalacturonic sodium were 2.098 mmol/L and 0.955 mmol/s, respectively. ErPL2 endolytically degraded pectic substances into oligosaccharides with degree of polymerization (DP) 1–5. To improve the thermostability and pH operation range, recombinant ErPL2 was immobilized onto mesoporous titanium oxide particles (MTOPs). MTOPs have abundant hydroxyl groups on the surface, which is a non-toxicity and good biocompatibility carrier. The residual enzyme activity of immobilized ErPL2 at 40 °C increased remarkably from 11% to 91% compared with free enzyme. The operable pH range was extended from 8–9 to 9–11. Surprisingly, the catalytic efficiency of immobilized ErPL2 was about 19 times higher than free enzyme. To our knowledge this is the first attempt of pectate lyase immobilized on MTOPs and it provides a new option for improving the catalytic performance.
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Biomaterials Advances
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2022
·
IF 0
Lichao Chen,Bo Wang,Haohao Ren,Yanan Wu,Defu Lyu,Yanan Ouyang,Qiyi Zhang,Yonggang Yan
Poly-amino acid (PAA) is a promising biomaterial in biomedical engineering due to its similar amide bond structure to collagen and excellent biocompatibility, but the lack of osteogenic activity and inferior mechanical strength limit its long-term application in orthopedics. In this study, a poly-amino acid/poly (p-benzamide) (PAA-PBA) copolymer with high mechanical strength was designed and fabricated by the method of solution polymerization. The chain structures, thermal properties and mechanical properties of these polymers were evaluated and results showed that PBA greatly promoted the mechanical properties of PAA, and the copolymer performed the maximum mechanical strengths with compressive strength, bending strength and tensile strength of 123 MPa, 107 MPa and, 95 MPa, respectively. To increase the bioactivity of surface, a bioactive coating that consists of poly-(dopamine) (PDA) nanolayers and tripeptide Arginine-Glycine-Aspartic acid (RGD) on sulfonated PAA-PBA copolymer was created. A porous structure appeared on the surface after modification, the surface roughness and hydrophilicity of copolymer has been improved obviously after introducing PDA and RGD peptide coating. The in vitro bioactivity evaluation demonstrated that the RGD-functionalized sample showed a significantly improved ability to promote bone apatite mineralization, cell adhesion, proliferation and osteogenic differentiation. In a word, such a strategy of material synthesis and surface modification method shows a great potential for broadening the use of PAA in the application of load-bearing bone substitute biomaterials.
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Biomass Conversion and Biorefinery
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2022
·Vol. 13
·期 17
·15837-15844
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IF 4.05
Di Junhua,Qin Lizhen,He Yu-Cai
A new type of metal-free solid acid catalyst ChCl:OA-SG(SiO 2 ) was firstly synthesized by loading deep eutectic solvent ChCl:oxalic acid on silica with sol–gel process using tetraethyl orthosilicate as silicon source. The properties of the catalyst were characterized by Fourier transform infrared spectrum, X-ray diffraction, scanning electron microscope, and Brunauer-Emmet-Teller. Highest furfural (FF) yield reached 41.2% from corncob with ChCl:OA-SG(SiO 2 ) catalyst (2.0 wt%) in water at 170 °C for 0.5 h. The catalytic mechanism of ChCl:OA-SG(SiO 2 )-catalyzed biomass into furfural was interpreted in the aqueous system. Corncob-valorized FF was wholly transformed to furfuryl alcohol with recombinant Escherichia coli CG-19 cells after bioreduction for 3 h of at 30 °C and pH 7.0. Yield of 0.416 g furfuryl alcohol/g xylan in corncob was obtained. This established hybrid catalysis could efficiently valorize biomass into value-added furfuryl alcohol.
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FOOD CHEMISTRY
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2022
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IF 9.231
Cong Chen,Fei Yu,Xinli Wen,Shuna Chen,Kaixi Wang,Feiquan Wang,Jianming Zhang,Yuanyuan Wu,Puming He,Youying Tu,Bo Li
Two major green leaf volatiles (GLVs) in tea that contribute greatly to tea aroma, particularly the green odor, are (E)-2-hexenal and (Z)-3-hexenal. Until now, their formation and related mechanisms during tea manufacture have remained unclear. Our data showed that the contents of (E)-2-hexenal and (Z)-3-hexenal increased more than 1000-fold after live tea leaves were torn. Subsequently, a new (Z)-3:(E)-2-hexenal isomerase (CsHI) was identified in Camellia sinensis . CsHI irreversibly catalyzed the conversion of (Z)-3-hexenal to (E)-2-hexenal . Abiotic stresses including low temperature, dehydration, and mechanical wounding, did not influence the (E)-2-hexenal content in intact tea leaves during withering, but regulated the proportions of (Z)-3-hexenal and (E)-2-hexenal in torn leaves by modulating CsHI at the transcript level. For the first time, this work reveals the formation of (E)-2-hexenal during tea processing and suggests that CsHI may play a pivotal role in tea flavor development as well as in plant defense against abiotic stresses.
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BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2023
·
IF 2.8
Shijin Wu,Qiang Wang,Xiaojing Ma,Lequan Qiu,Hongde Yan
The amino acid residues at the entrance of the catalytic pocket may impose steric hindrance on the substrate to enter the active center of the enzyme. Based on the analysis of the three-dimensional structure of the Saccharomyces cerevisiae old yellow enzyme 3 (OYE3), four bulky residues were chosen and mutated to small amino acids. The results showed that mutation of the W116 residue had interesting impacts on the catalytic performance. All four variants became inactive for the reduction of ( R )-carvone and ( S )-carvone, but inverted the stereoselectivity for the reduction of ( E / Z )-citral. The mutation of the F250 residue had a more positive effect on the activity and stereoselectivity. Two variants, F250A and F250S, showed excellent diastereoselectivity and activity for the reduction of ( R )-carvone (de > 99%, c > 99%) and increased diastereoselectivity and activity for the reduction of ( S )-carvone (de > 96%, c > 80%). One variant of the P295 residue, P295G, displayed excellent diastereoselectivity and activity only for the reduction of ( R )-carvone (de > 99%, c > 99%). Mutation of the Y375 residue had a negative impact on the activity of the enzyme. These findings provide some solutions for rational enzyme engineering of OYE3.
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