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Yu B, Luo S, Ding Y, Gong Z, Nie T. Insights into glycosidic bond specificity of an engineered selective α-L-rhamnosidase N12-Rha via activity assays and molecular modelling. AMB Express 2022; 12:143. [DOI: 10.1186/s13568-022-01489-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 11/03/2022] [Indexed: 11/13/2022] Open
Abstract
AbstractαL-rhamnosidase (EC 3.2.1.40) has been widely used in food processing and pharmaceutical preparation. The recombinant α-L-rhamnosidase N12-Rha from Aspergillus niger JMU-TS528 had significantly higher catalytic activity on α-1,6 glycosidic bond than α-1,2 glycosidic bond, and had no activity on α-1,3 glycosidic bond. The activities of hydrolyzed hesperidin and naringin were 7240 U/mL and 945 U/mL, respectively, which are 10.63 times that of native α-L-rhamnosidase. The activity could maintain more than 80% at pH 3–6 and 40–60℃. Quantum chemistry calculations showed that charge difference of the C-O atoms of the α-1,2, α-1,3 and α-1,6 bonds indicated that α-1,6 bond is most easily broken and α-1,3 bond is the most stable. Molecular dynamics simulations revealed that the key residue Trp359 that may affect substrate specificity and the main catalytic sites of N12-Rha are located in the (α/α)6-barrel domain.
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Huang P, Luo FJ, Ma YC, Wang SX, Huang J, Qin DD, Xue FF, Liu BY, Wu Q, Wang XL, Liu GQ. Dual antioxidant activity and the related mechanisms of a novel pentapeptide GLP4 from the fermented mycelia of Ganoderma lingzhi. Food Funct 2022; 13:9032-9048. [PMID: 35943028 DOI: 10.1039/d2fo01572b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxidative stress causes chronic inflammation, and mediates various diseases. The discovery of antioxidants from natural sources is important to research. Here we identified a novel antioxidant peptide (GLP4) from Ganoderma lingzhi mycelium and investigated its antioxidant type and potential protective mechanisms. Through free radical scavenging assay, active site shielding validation, superoxide dismutase (SOD) activity assay, and lipid peroxidation assay, we demonstrated that GLP4 was a novel protective agent with both direct and indirect antioxidant activities. GLP4 could directly enter human umbilical vein endothelial cells (HUVECs) as an exogenous substance. Meanwhile, GLP4 promoted the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and activated the Nrf2/antioxidant response element (ARE) signaling pathway, exhibiting antioxidant and anti-apoptotic cytoprotective effects on hydrogen peroxide (H2O2)-induced HUVECs. Pull-down experiments of GLP4 target proteins, bioinformatics analysis and molecular docking further revealed that GLP4 mediated Nrf2 activation through binding to phosphoglycerate mutase 5 (PGAM5). The results suggested that GLP4 is a novel peptide with dual antioxidant activity and has promising potential as a protective agent in preventing oxidative stress-related diseases.
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Affiliation(s)
- Ping Huang
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Fei-Jun Luo
- Laboratory of Molecular Nutrition, National Engineering Research Center for Rice and Byproducts, Central South University of Forestry and Technology, Changsha 410004, China
| | - You-Chu Ma
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Si-Xian Wang
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Jia Huang
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Dan-Dan Qin
- Laboratory of Molecular Nutrition, National Engineering Research Center for Rice and Byproducts, Central South University of Forestry and Technology, Changsha 410004, China
| | - Fei-Fei Xue
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Bi-Yang Liu
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Qiang Wu
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Xiao-Ling Wang
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
| | - Gao-Qiang Liu
- Hunan Provincial Key Laboratory of Forestry Biotechnology & International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China. .,Microbial Variety Creation Center, Yuelushan National Laboratory of Seed Industry, Changsha 410004, China
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Wang S, Zhu J, Zhang S, Zhang X, Ge F, Xu Y. The catalytic degradation of nitrobenzene by the Cu-Co-Fe-LDH through activated oxygen under ambient conditions. Dalton Trans 2020; 49:3999-4011. [PMID: 32057042 DOI: 10.1039/c9dt03794b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Efficient and low-cost catalysts for catalytic wet air oxidation (CWAO) under ambient conditions are of great significance for the degradation of hydrophobic organic contaminants. In this study, four LDH catalysts were prepared and their catalytic performance was studied by the degradation of nitrobenzene. The CuCoFe-LDH shows the best catalytic activity with an NB removal efficiency of 41.2%. The CuCoFe-LDH exhibited a typical layer structure, with a specific surface area of 167.32 m2 g-1, and Cu2+, Co2+ and Fe3+ were evenly dispersed on the crystal. The NB removal efficiency was increased by 12.5% through adding formic acid. After five recycling processes, the NB removal efficiency was 18.9% because 3.8 mg g-1 of Co was leached out of the LDH. In the CWAO process, H2O2, ˙OH, ˙O2- and 1O2 were successfully formed through activated oxygen by the CuCoFe-LDH catalyst under ambient conditions. This work further broadens the application scope of layered double hydroxides (LDHs) in the degradation of organic pollutants by CWAO under ambient conditions.
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Affiliation(s)
- Shaohong Wang
- Department of Environment, College of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, P. R. China.
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Dai Y, Hua Q, Ling J, Shao C, Zhong C, Zhang X, Hu Y, Zhang L, Liu Y. Quantum chemical calculation of free radical substitution reaction mechanism of camptothecin. J Mol Graph Model 2018; 84:174-181. [PMID: 30015049 DOI: 10.1016/j.jmgm.2018.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 12/31/2022]
Abstract
Free radical substitution reaction, which has low energy barrier and takes place in mild reaction conditions, is an important method for camptothecin's modification. The experimental data show that the free radical substitution reaction of camptothecin has high site selectivity, and prefers to take place at site 7. Up to now, few researches focus on the mechanism of it. In this study, the differences of the reaction rate constant (k) for the reactions at different sites, such as site of 7, 9, 10, 11, 12, were investigated with B3LYP of density functional theory at the 6-31 + G (d, p) base set level and CPCM aqueous solvent model. It was found that the substitution reaction can be carried out in two steps in acidic condition. First, the methyl radical attacks the corresponding site to form an intermediate having methyl radical combined with the camptothecin skeleton, and then a hydrogen atom was abstracted by the singlet oxygen to form methyl camptothecin, wherein the first step was the rate control step of the reaction. The results show that site 7 has the higherreaction rate constant (k) than other examined sites, indicating that the reaction tends to take place on site 7 position, which is in agreement with the experimental results.
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Affiliation(s)
- Yujie Dai
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China.
| | - Qingyuan Hua
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Jun Ling
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Chunfu Shao
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Cheng Zhong
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Xiuli Zhang
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Yanying Hu
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Liming Zhang
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
| | - Yaotian Liu
- Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science & Technology), Ministry of Education, College of Bioengineering, Tianjin University of Science and Technology, No.29 of 13th Street, TEDA, Tianjin, 300457, PR China
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