Expression, Purification and Properties of Shikimate Dehydrogenase from Mycobacterium Tuberculosis

Zhang, Xuelian,Zhang, Shunbao,Hao, Fang,Lai, Xuhui,Yu, Haidong,Huang, Yishu,Wang, Honghai Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.5

Tuberculosis, caused by Mycobacterium tuberculosis, continues to be one of the main diseases to mankind. It is urgent to discover novel drug targets for appropriate antimicrobial agents against this human pathogen. The shikimate pathway is onsidered as an attractive target for the discovery of novel antibiotics for its essentiality in bacteria and absence in mammalian cells. The Mycobacterium tuberculosis aroE-encoded shikimate dehydrogenase was cloned, expressed and purified. Sequence alignment analysis shows that shikimate dehydrogenase of Mycobacterium tuberculosis exhibit the pattern of G-X-(N/S)-V-(T/S)-X-PX-K, which is highly conserved within the shikimate dehydrogenase family. The recombinant shikimate dehydrogenase spectrum determined by CD spectroscopy showed that the percentages for $\alpha$-helix, $\beta$-sheet, $\beta$-turn, and random coil were 29.2%, 9.3%, 32.7%, and 28.8%, respectively. The enzymatic characterization demonstrates that it appears to be fully active at pH from 9.0 to 12, and temperature $63^{\circ}C$. The apparent Michaelis constant for shikimic acid and $NADP^+$ were calculated to be about $29.5\;{\mu}M$ and $63\;{\mu}M$. The recombinant shikimate dehydrogenase catalyzes the substrate in the presence of $NADP^+$ with an enzyme turnover number of $399\;s^{-1}$. Zymological studies suggest that the cloned shikimate dehydrogenase from M. tuberculosis has a pretty activity, and the work should help in the discovery of enzyme inhibitors and further of possible antimicrobial agents against Mycobacterium tuberculosis.

MIL-53(Fe)@γ-Al2O3 nanocomposites incorporated cellulose acetate for forward osmosis membranes of high desalination performance

Tong Li,Xuelian Ba,Xiuju Wang,Zhongpeng Wang,Jie Yang,Yu Cui,Liguo Wang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

Forward osmosis (FO) membrane is a promising membrane technique. However, its application in desalination is limited. Thus, we synthesized MIL-53(Fe)@γ-Al2O3 via solvent-thermal method to fabricate MIL-53(Fe)@γ-Al2O3/cellulose acetate (CA) composite membranes of high desalination performance. MIL-53(Fe)@γ-Al2O3 and MIL-53(Fe) particles were studied using XRD, FITR, SEM, N2 adsorption-desorption isotherms, and AFM. The structural features of MIL-53(Fe)@γ-Al2O3/CA membrane and MIL-53(Fe)/CA membrane were analyzed using SEM, AFM and water contact angle. The reverse salt flux and water flux of the MIL-53(Fe)@γ-Al2O3/CA membrane reached 1.78 g m−2 h−1 and 37.1 L m−2 h−1, respectively, when the deionized water and 1 M NaCl solution were the feed solution and traction solution, respectively. Compared to the MIL-53(Fe)/CA membrane, the MIL-53(Fe)@γ-Al2O3/CA membrane demonstrated better perviousness and selectivity properties of the membrane. This study shows a potential advantage of MOF composites as additives for improvement in the desalination performance of forward osmosis membranes.

MIL-53(Fe)@γ-Al₂O₃ nanocomposites incorporated cellulose acetate for forward osmosis membranes of high desalination performance

Tong Li,Xuelian Ba,Xiuju Wang,Zhongpeng Wang,Jie Yang,Yu Cui,Liguo Wang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

Forward osmosis (FO) membrane is a promising membrane technique. However, its application in desalination is limited. Thus, we synthesized MIL-53(Fe)@γ-Al₂O₃ via solvent-thermal method to fabricate MIL-53(Fe)@γ-Al₂O₃/cellulose acetate (CA) composite membranes of high desalination performance. MIL-53(Fe)@γ-Al₂O₃ and MIL-53(Fe) particles were studied using XRD, FITR, SEM, N₂ adsorption-desorption isotherms, and AFM. The structural features of MIL-53(Fe)@γ-Al₂O₃/CA membrane and MIL-53(Fe)/CA membrane were analyzed using SEM, AFM and water contact angle. The reverse salt flux and water flux of the MIL-53(Fe)@γ-Al₂O₃/CA membrane reached 1.78 g m<SUP>-2</SUP> h<SUP>-1</SUP> and 37.1 L m<SUP>-2 </SUP>h<SUP>-1</SUP>, respectively, when the deionized water and 1 M NaCl solution were the feed solution and traction solution, respectively. Compared to the MIL-53(Fe)/CA membrane, the MIL-53(Fe)@γ-Al₂O₃/CA membrane demonstrated better perviousness and selectivity properties of the membrane. This study shows a potential advantage of MOF composites as additives for improvement in the desalination performance of forward osmosis membranes.

Four new compounds from the bulbs of Lycoris aurea with neuroprotective effects against CoCl2 and H2O2-induced SH-SY5Y cell injuries

An Jin,Xuelian Xiang,Yun-Yun Zhu,Heng-Yi Yu,Hui-Fang Pi,Peng Zhang,Han-Li Ruan 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.3

Three new alkaloids, 2a-hydroxy-6-O-n-butyloduline,O-n-butyllycorenine, (-)-N-(chloromethyl)lycoramine(1–3), and a new phenolic compound, ((7S)-7-(4-hydroxyphenyl)-7-hydroxypropyl)-20-methylbenzene-30,60-diol (14), along with ten known alkaloids (4–13), wereisolated from the bulbs of Lycoris aurea collected fromHuaihua County of Hunan Province, China. Their structureswere elucidated by spectroscopic methods includingHRESIMS, UV, IR, and NMR. All the isolated compoundswere tested for their neuroprotective effects against CoCl2and H2O2-induced SH-SY5Y cell death. Compounds 1–7and 10 exhibited significant neuroprotective effects againstCoCl2-induced SH-SY5Y cell injury, while compounds1–5, 7, 10 and 12 showed obvious neuroprotective effectsagainst H2O2-induced SH-SY5Y cell death.

Dynamic colonization of gut microbiota and its influencing factors among the breast-feeding infants during the first two years of life

Li Ping,Chang Xuelian,Chen Xiaoyu,Tang Tiantian,Liu Yajing,Shang Yu,Qi Kemin 한국미생물학회 2022 The journal of microbiology Vol.60 No.8

The maturation of infant gut microbiota has lifelong implications on health, which has been proposed as the major events during the first year of life. However, little is known about their dynamic colonization and influencing elements among the first two-year infancy as well as into the adulthood. So based on the 16S rRNA sequencing data among 30 healthy breast-feeding mother-infant pairs with normal ranges of growth and development indicators from birth to two years old, the dynamic colonization of gut microbiota and its influencing factors were discussed using this birth cohort. Among these, we identified that the diversity of gut microbiota was significantly increased from six-month to two-year subgroups. The significantly dynamic trends of gut microbiota at the phylum (genus) level were that the percents of Firmicutes (Faecalibacterium, Blautia, Enterococcus, Subdoligranulum, Agathobacter, unidentified_Erysipelotrichaceae, Staphylococcus, unidentified_Ruminococcaceae, and Fusicatenibacter), Bacteroidetes and Verrucomicrobia were increased, while Actinobacteria (Bifidobacterium) and Proteobacteria (unidentified- Enterobacteriaceae and Klebsiella) were decreased with the increased ages from six months to two years old, which might simultaneously modulate the host pathways, such as the higher percents of chemoheterotrophy and fermentation, and lower percentages of nitrate_reduction, aerobic_chemoheterotrophy and so on. Furthermore, there were significant associations between maternal (milk microbiota, pre-pregnancy BMI, BMI increment during the pregnancy)/infant characteristics (BMI at birth and BMI gain), and the compositions of gut microbiota. However, no differences of gut microbiota were shown between the different sex and productive mode subgroups. Overall, the colonization of gut microbiota is significantly matured into the adulthood with the increased ages to two-years old and regulated by the above maternal/infant characteristics, which will provide a new direction for the host-gut microbiota interplay during the first two years of life.

Expression, Purification and Properties of Shikimate Dehydrogenasefrom Mycobacterium Tuberculosis

Xuhui Lai,Honghai Wang,Xuelian Zhang,Shunbao Zhang,Fang Hao,Haidong Yu,Yishu Huang 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.5

Construction, Investigation and Application of TEV Protease Variants with Improved Oxidative Stability

( Enkhtuya Bayar ),( Yuanyuan Ren ),( Yinghua Chen ),( Yafang Hu ),( Shuncheng Zhang ),( Xuelian Yu ),( Jun Fan ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.12

Tobacco etch virus protease (TEVp) is a useful tool for removing fusion tags, but wild-type TEVp is less stable under oxidized redox state. In this work, we introduced and combined C19S, C110S and C130S into TEVp variants containing T17S, L56V, N68D, I77V and S135G to improve protein solubility, and S219V to inhibit self-proteolysis. The solubility and cleavage activity of the constructed variants in Escherichia coli strains including BL21(DE3), BL21(DE3)pLys, Rossetta(DE3) and Origami(DE3) under the same induction conditions were analyzed and compared. The desirable soluble amounts, activity, and oxidative stability were identified to be reluctantly favored in the TEVp. Unlike C19S, C110S and C130S hardly impacted on decreasing protein solubility in the BL21(DE3), but they contributed to improved tolerance to the oxidative redox state in vivo and in vitro. After two fusion proteins were cleaved by purified TEVp protein containing double mutations under the oxidized redox state, the refolded disulfide-rich bovine enterokinase catalytic domain or maize peroxidase with enhanced yields were released from the regenerated amorphous cellulose via affinity absorption of the cellulose-binding module as the affinity tag.

Kinetics of polyvinyl butyral hydrolysis in ethanol/water solutions

Wenwen Luan,Chunyu Wang,Zuoxiang Zeng,Weilan Xue,Xuelian He,Yu Bai 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.9

The hydrolysis kinetics of polyvinyl butyral (PVB) was studied in ethanol/water mixed solvents in the temperature range of 339.15-355.15 K, and a three-step hypothesis was proposed to describe the hydrolysis process. The influences of stirring speed, ethanol content and temperature on the hydrolysis of PVB were investigated, and an induction period (IP) phenomenon was found in the process of PVB hydrolysis. The ethanol content in the mixed solvents has a great influence on IP, which is due to the formation of the two kinds of water-ethanol clusters in the system. Temperature influences the IP by changing the catalytic activity of hydroxylamine hydrochloride (HH) on the hydrolysis of PVB. The shrinking core models with three controlling steps were used to fit the kinetic data, and the results indicate that the model controlled by chemical reaction is suitable to describe the kinetic behavior of PVB hydrolysis.