ENZYME AND MICROBIAL TECHNOLOGY
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2021
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IF 3.493
Yue Shan,Weili Yu,Lijuan Shen,Xuan Guo,He Zheng,Jinyi Zhong,Tao Hu,Yinglun Han
Haloalkane dehalogenase DhaA catalyzes the hydrolytic cleavage of carbon-halogen bonds and produces alcohol, a proton and a halide. However, DhaA suffers from the poor environmental stability, such as sensitivity to high temperature, low pH, hypersaline and organic solvent. In order to improve the environmental stability of DhaA, DhaA was covalently conjugated with inulin, a hydrophilic polysaccharide in the present study. Each DhaA was averagely conjugated with 7∼8 inulin molecules. The conjugated inulin could form a hydration layer around DhaA, which increased the conformational rigidity and decreased the entropy of the enzyme. Conjugation of inulin maintained 75.5 % of the enzymatic activity of DhaA and slightly altered the structure of DhaA. As compared with DhaA, the conjugate (inu-DhaA) showed slightly different kinetic parameters (K m of 2.9 μmol/L and K cat of 1.0 s −1 ). Inulin conjugation could delay the structural unfolding and/or slow the protonation process of DhaA under undesirable environment, including the long-term storage, low pH, hypersaline and organic solvent stability. As a result, the environmental stability of DhaA was markedly increased upon conjugation with inulin. Thus, inulin conjugation was an effective approach to enhance the environmental stability of DhaA.
研究领域:
生物化学
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酶工程
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DOI
PubMed
高影响因子
JOURNAL OF BIOTECHNOLOGY
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2021
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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
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酶工程
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环境生物学
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DOI
PubMed
高影响因子
ANALYST
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2022
·Vol. 147
·期 7
·1341-1347
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IF 5.227
Chen-Chen Jiang,Xiao-Chong Li,Jian-Ang Fan,Jia-Ying Fu,Xu-Nan Huang-Fu,Jia-Jie Li,Ju-Fang Zheng,Xiao-Shun Zhou,Ya-Hao Wang
The electroreductive cleavage of carbon–halogen bonds has attracted increasing attention in both electrosynthesis and pollution remediation. Herein, by employing the in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique, we have successfully investigated the electroreductive dehalogenation process of aryl halides with the thiol group on a smooth Au electrode in aqueous solution at different pH values. The obtained potential-dependent Raman spectra directly reveal a mixture of the reduction products 4,4′-biphenyldithiol (BPDT) and thiophenol (TP). The conversion ratios of the C–Cl and C–Br bonds at pH = 7 are 37% and 55%, respectively. Furthermore, quantitative analysis of the intensity variations of ν(C–Cl), ν(C–Br) and aromatic ν(CC) stretching modes suggests electroreductive dehalogenation via both direct electron transfer reduction and electrocatalytic hydrodehalogenation. Molecular evidence for the C–C cross coupling process through TP reaction with benzene free radical intermediates is found at negative potentials, which leads to the increasing selectivity of biphenyl products.
研究领域:
电化学
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材料科学
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环境科学
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PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2024
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IF 3.3
Jingjie Tang,Luying Xie,Jiayu Liu,Shangyu Shi,Qikun Yang,Bo Zhang,Yingying Wang,Lin Chen,Shaohui Jia,Mingfang Ma,Zengyang Xie
Highly efficient and practical carbon–chalcogen (S, Se) and amide bonds formation methodologies for the synthesis of thio- and seleno-acetamides were developed, via the base-promoted one-pot two-step reactions of 2-amino(benzo)thiazoles and aryl acetyl chlorides with dichalcogenides. This cross-coupling reaction afforded the goal products that had been chalcogenated regioselectively in moderate to good yields. Further transformations of the new synthesized compounds, DFT calculations and preliminary mechanism studies are discussed as well.
研究领域:
有机化学
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计算化学
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PubMed
高影响因子
TETRAHEDRON
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2022
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IF 2.388
Wenfeng Zhong,Weiping Xu,Qin Yang,Terumasa Kato,Yan Liu,Keiji Maruoka
Using organosilicon compounds of the type Me 3 SiX (X = CN, N 3 , C n F 2n+1 , and halogens) and an amine base, alkylsilyl peroxides were generated in situ from the corresponding alkyl hydroperoxides . Subsequent in situ copper-catalyzed homolytic cleavage of the alkylsilyl peroxides afforded alkyl radicals, which were then trapped with a nucleophile X (X = CN, N 3 , C n F 2n+1 , and halogens) to furnish coupling products with new carbon–carbon, carbon–nitrogen, or carbon–halogen bonds in good to high yields. In addition, 1-(trimethylsilyl)morpholine can also be employed for the in-situ-generation of alkylsilyl peroxides, which are subsequently utilized for N-alkylation of amides, arylations , and borylations with high efficiency.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）