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33 results on '"Liu, Qing-mei"'

1. Fast Impurity Solver for Dynamical Mean Field Theory based on second order perturbation around the atomic limit

Author

Zhuang, Jia Ning, Liu, Qing Mei, Fang, Zhong, and Dai, Xi

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

An impurity solver for the dynamical mean field (DMFT) study of the Mott insulators is proposed, which is based on the second order perturbation of the hybridization function. After carefully benchmarking it with Quantum Monte Carlo results on the anti-ferromagnetic phase of the Hubbard model, we conclude that this impurity solver can capture the main physical features in the strong coupling regime and can be a very useful tool for the LDA+DMFT studies of the Mott insulators with long range order., Comment: 12 pages, 8 figures

Published
2009

3. Citriquinolinones A and B: Rare Isoquinolinone-Embedded Citrinin Analogues and Related Metabolites from the Deep-Sea-Derived Aspergillus versicolor 170217

Author

Lin, Shui-Hua, primary, Yan, Qing-Xiang, additional, Zhang, Yong, additional, Wu, Tai-Zong, additional, Zou, Zheng-Biao, additional, Liu, Qing-Mei, additional, Jiang, Jia-Yang, additional, Xie, Ming-Min, additional, Xu, Lin, additional, Hao, You-Jia, additional, Liu, Zhu, additional, Liu, Guang-Ming, additional, and Yang, Xian-Wen, additional

Published
2023
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8. Identification and Characterization of a Mucilaginibacter sp. Strain QM49 β-Glucosidase and Its Use in the Production of the Pharmaceutically Active Minor Ginsenosides (S)-Rh1 and (S)-Rg2

Author

Cui, Chang-Hao, Liu, Qing-Mei, Kim, Jin-Kwang, Sung, Bong-Hyun, Kim, Song-Gun, Kim, Sun-Chang, and Im, Wan-Taek

Subjects
Ginsenosides, Bacteroidetes, Recombinant Fusion Proteins, beta-Glucosidase, Molecular Sequence Data, Gene Expression, Sequence Homology, Sequence Analysis, DNA, Molecular Weight, Kinetics, Escherichia coli, Cluster Analysis, Enzymology and Protein Engineering, Biotransformation
Abstract

Here, we isolated and characterized a new ginsenoside-transforming β-glucosidase (BglQM) from Mucilaginibacter sp. strain QM49 that shows biotransformation activity for various major ginsenosides. The gene responsible for this activity, bglQM, consists of 2,346 bp and is predicted to encode 781 amino acid residues. This enzyme has a molecular mass of 85.6 kDa. Sequence analysis of BglQM revealed that it could be classified into glycoside hydrolase family 3. The enzyme was overexpressed in Escherichia coli BL21(DE3) using a maltose binding protein (MBP)-fused pMAL-c2x vector system containing the tobacco etch virus (TEV) proteolytic cleavage site. Overexpressed recombinant BglQM could efficiently transform the protopanaxatriol-type ginsenosides Re and Rg1 into (S)-Rg2 and (S)-Rh1, respectively, by hydrolyzing one glucose moiety attached to the C-20 position at pH 8.0 and 30°C. The Km values for p-nitrophenyl-β-d-glucopyranoside, Re, and Rg1 were 37.0 ± 0.4 μM and 3.22 ± 0.15 and 1.48 ± 0.09 mM, respectively, and the Vmax values were 33.4 ± 0.6 μmol min(-1) mg(-1) of protein and 19.2 ± 0.2 and 28.8 ± 0.27 nmol min(-1) mg(-1) of protein, respectively. A crude protopanaxatriol-type ginsenoside mixture (PPTGM) was treated with BglQM, followed by silica column purification, to produce (S)-Rh1 and (S)-Rg2 at chromatographic purities of 98% ± 0.5% and 97% ± 1.2%, respectively. This is the first report of gram-scale production of (S)-Rh1 and (S)-Rg2 from PPTGM using a novel ginsenoside-transforming β-glucosidase of glycoside hydrolase family 3.

Published
2013

9. Fast Impurity Solver for Dynamical Mean Field Theory based on second order perturbation around the atomic limit

Author

Dai Xi, Liu Qing-Mei, Fang Zhong, and Zhuang Jia-Ning

Subjects
Physics, Condensed Matter::Quantum Gases, Hubbard model, Strongly Correlated Electrons (cond-mat.str-el), Quantum Monte Carlo, Mott insulator, Monte Carlo method, General Physics and Astronomy, FOS: Physical sciences, Electronic structure, Solver, Condensed Matter - Strongly Correlated Electrons, Mean field theory, Quantum electrodynamics, Condensed Matter::Strongly Correlated Electrons, Local-density approximation
Abstract

An impurity solver for the dynamical mean field (DMFT) study of the Mott insulators is proposed, which is based on the second order perturbation of the hybridization function. After carefully benchmarking it with Quantum Monte Carlo results on the anti-ferromagnetic phase of the Hubbard model, we conclude that this impurity solver can capture the main physical features in the strong coupling regime and can be a very useful tool for the LDA+DMFT studies of the Mott insulators with long range order., Comment: 12 pages, 8 figures

Published
2009
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13. Bioconversion of ginsenosides Rb1, Rb2, Rc and Rd by novel β-glucosidase hydrolyzing outer 3-O glycoside from Sphingomonas sp. 2F2: Cloning, expression, and enzyme characterization

Author

Wang, Liang, Liu, Qing-Mei, Sung, Bong-Hyun, An, Dong-Shan, Lee, Hyung-Gwan, Kim, Song-Gun, Kim, Sun-Chang, Lee, Sung-Taik, and Im, Wan-Taek

Subjects
*BIOCONVERSION, *GLUCOSIDASES, *MOLECULAR cloning, *GENE expression, *SPHINGOMONAS, *BACTERIAL proteins, *NUCLEOTIDE sequence, *ENZYME activation
Abstract

Abstract: A new β-glucosidase gene (bglSp) was cloned from the ginsenoside converting Sphingomonas sp. strain 2F2 isolated from the ginseng cultivating filed. The bglSp consisted of 1344bp (447 amino acid residues) with a predicted molecular mass of 49,399Da. A BLAST search using the bglSp sequence revealed significant homology to that of glycoside hydrolase superfamily 1. This enzyme was overexpressed in Escherichia coli BL21 (DE3) using a pET21-MBP (TEV) vector system. Overexpressed recombinant enzymes which could convert the ginsenosides Rb1, Rb2, Rc and Rd to the more pharmacological active rare ginsenosides gypenoside XVII, ginsenoside C-O, ginsenoside C-Mc1 and ginsenoside F2, respectively, were purified by two steps with Amylose-affinity and DEAE-Cellulose chromatography and characterized. The kinetic parameters for β-glucosidase showed the apparent K m and V max values of 2.9±0.3mM and 515.4±38.3μmolmin−1 mg of protein−1 against p-nitrophenyl-β-d-glucopyranoside. The enzyme could hydrolyze the outer C3 glucose moieties of ginsenosides Rb1, Rb2, Rc and Rd into the rare ginsenosides Gyp XVII, C-O, C-Mc1 and F2 quickly at optimal conditions of pH 5.0 and 37°C. A little ginsenoside F2 production from ginsenosides Gyp XVII, C-O, and C-Mc1 was observed for the lengthy enzyme reaction caused by the side ability of the enzyme. [Copyright &y& Elsevier]

Published
2011
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14. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Subjects
food allergy, immunosuppression, p38 MAPK, sulfated polysaccharide from Gracilaria lemaneiformis
Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

15. Eucheuma cottonii sulfated oligosaccharides decrease food allergic responses in animal models by up-regulating regulatory T (Treg) cells

Author

Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, Liu, Guang-Ming, Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2−97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

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16. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, Liu, Guang-Ming, Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

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17. Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models

Author

Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, Liu, Guang-Ming, Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin.

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18. Eucheuma cottonii sulfated oligosaccharides decrease food allergic responses in animal models by up-regulating regulatory T (Treg) cells

Author

Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, Liu, Guang-Ming, Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2−97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

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19. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, Liu, Guang-Ming, Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

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20. Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models

Author

Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, Liu, Guang-Ming, Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin.

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21. Eucheuma cottonii sulfated oligosaccharides decrease food allergic responses in animal models by up-regulating regulatory T (Treg) cells

Author

Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, Liu, Guang-Ming, Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2−97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

Full Text
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22. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, Liu, Guang-Ming, Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

Full Text
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23. Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models

Author

Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, Liu, Guang-Ming, Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin.

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24. Eucheuma cottonii sulfated oligosaccharides decrease food allergic responses in animal models by up-regulating regulatory T (Treg) cells

Author

Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, Liu, Guang-Ming, Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2−97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

Full Text
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25. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, Liu, Guang-Ming, Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

Full Text
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26. Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models

Author

Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, Liu, Guang-Ming, Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin.

Full Text
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27. Eucheuma cottonii sulfated oligosaccharides decrease food allergic responses in animal models by up-regulating regulatory T (Treg) cells

Author

Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, Liu, Guang-Ming, Xu, Sha-Sha, Liu, Qing-Mei, Xiao, An-Feng, Maleki, Soheila J., Alcocer, Marcos, Gao, Yuan-Yuan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2−97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

Full Text
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28. Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK

Author

Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, Liu, Guang-Ming, Liu, Qing-Mei, Yang, Yang, Maleki, Soheila J., Alcocer, Marcos, Xu, Sha-Sha, Shi, Chao-Lan, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients.

Full Text
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29. Allergenicity and oral tolerance of enzymatic cross-linked tropomyosin evaluated using cell and mouse models

Author

Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, Liu, Guang-Ming, Liu, Guang-Yu, Hu, Meng-Jun, Sun, Le-Chang, Han, Xin-Yu, Liu, Qing-Mei, Alcocer, Marcos J.C., Fei, Dan-Xia, Cao, Min-Jie, and Liu, Guang-Ming

Abstract

The enzymatic cross-linking of proteins to form high-molecular-weight compounds may alter their sensitization potential. The IgG-/IgE-binding activity, digestibility, allergenicity, and oral tolerance of cross-linked tropomyosin with tyrosinase (CTC) or horseradish peroxidase (CHP) were investigated. ELISA results demonstrated CTC or CHP reduced its IgE-binding activity by 34.5 ± 1.8 and 63.5 ± 0.6%, respectively. Compared with native tropomyosin or CTC, CHP was more easily digested into small fragments; CHP decreased the degranulation of RBL-2H3 cells and increased endocytosis by dendritic cells. CHP can induce oral tolerance and reduce allergenicity in mice by decreasing IgE and IgG1 levels in serum, the production of T-cell cytokines, and the percentage composition of dendritic cells. These findings demonstrate CHP has more potential of reducing the allergenicity than CTC via influencing the morphology of protein, changing the original method of antigen presentation, modulating the Th1/Th2 immunobalance, and inducing the oral tolerance of the allergen tropomyosin.

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30. Identification and characterization of a Mucilaginibacter sp. strain QM49 β-glucosidase and its use in the production of the pharmaceutically active minor ginsenosides (S)-Rh1 and (S)-Rg2.

Author

Cui CH, Liu QM, Kim JK, Sung BH, Kim SG, Kim SC, and Im WT

Subjects
Bacteroidetes genetics, Biotransformation, Cluster Analysis, Escherichia coli genetics, Escherichia coli metabolism, Gene Expression, Kinetics, Molecular Sequence Data, Molecular Weight, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins isolation & purification, Recombinant Fusion Proteins metabolism, Sequence Analysis, DNA, Sequence Homology, beta-Glucosidase chemistry, beta-Glucosidase genetics, Bacteroidetes enzymology, Ginsenosides metabolism, beta-Glucosidase metabolism
Abstract

Here, we isolated and characterized a new ginsenoside-transforming β-glucosidase (BglQM) from Mucilaginibacter sp. strain QM49 that shows biotransformation activity for various major ginsenosides. The gene responsible for this activity, bglQM, consists of 2,346 bp and is predicted to encode 781 amino acid residues. This enzyme has a molecular mass of 85.6 kDa. Sequence analysis of BglQM revealed that it could be classified into glycoside hydrolase family 3. The enzyme was overexpressed in Escherichia coli BL21(DE3) using a maltose binding protein (MBP)-fused pMAL-c2x vector system containing the tobacco etch virus (TEV) proteolytic cleavage site. Overexpressed recombinant BglQM could efficiently transform the protopanaxatriol-type ginsenosides Re and Rg1 into (S)-Rg2 and (S)-Rh1, respectively, by hydrolyzing one glucose moiety attached to the C-20 position at pH 8.0 and 30°C. The Km values for p-nitrophenyl-β-d-glucopyranoside, Re, and Rg1 were 37.0 ± 0.4 μM and 3.22 ± 0.15 and 1.48 ± 0.09 mM, respectively, and the Vmax values were 33.4 ± 0.6 μmol min(-1) mg(-1) of protein and 19.2 ± 0.2 and 28.8 ± 0.27 nmol min(-1) mg(-1) of protein, respectively. A crude protopanaxatriol-type ginsenoside mixture (PPTGM) was treated with BglQM, followed by silica column purification, to produce (S)-Rh1 and (S)-Rg2 at chromatographic purities of 98% ± 0.5% and 97% ± 1.2%, respectively. This is the first report of gram-scale production of (S)-Rh1 and (S)-Rg2 from PPTGM using a novel ginsenoside-transforming β-glucosidase of glycoside hydrolase family 3.

Published
2013
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31. Novosphingobium ginsenosidimutans sp. nov., with the ability to convert ginsenoside.

Author

Kim JK, He D, Liu QM, Park HY, Jung MS, Yoon MH, Kim SC, and Im WT

Subjects
Bacterial Typing Techniques, Base Composition, Biotransformation, Cluster Analysis, Culture Media chemistry, DNA, Bacterial chemistry, DNA, Bacterial genetics, DNA, Ribosomal chemistry, DNA, Ribosomal genetics, Fatty Acids analysis, Fresh Water microbiology, Hydrogen-Ion Concentration, Molecular Sequence Data, Phylogeny, Quinones analysis, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Sphingomonadaceae genetics, Sphingomonadaceae metabolism, Temperature, beta-Glucosidase metabolism, Ginsenosides metabolism, Sphingomonadaceae classification, Sphingomonadaceae isolation & purification
Abstract

A Gram-negative, strictly aerobic, non-motile, non-sporeforming, and rod-shaped bacterial strain designated FW-6T was isolated from a freshwater sample and its taxonomic position was investigated by using a polyphasic approach. Strain FW-6T grew optimally at 10-42 degrees C and at pH 7.0 on nutrient and R2A agar. Strain FW-6T displayed beta- glucosidase activity that was responsible for its ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to Rd. On the basis of 16S rRNA gene sequence similarity, strain FW-6T was shown to belong to the family Sphingomonadaceae and was related to Novosphingobium aromaticivorans DSM 12444T (98.1% sequence similarity) and N. subterraneum IFO 16086T (98.0%). The G+C content of the genomic DNA was 64.4%. The major menaquinone was Q-10 and the major fatty acids were summed feature 7 (comprising C18:1 omega9c/ omega12t/omega7c), summed feature 4 (comprising C16:1 omega7c/iso- C15:0 2OH), C16:0, and C14:0 2OH. DNA and chemotaxonomic data supported the affiliation of strain FW-6T to the genus Novosphingobium. Strain FW-6T could be differentiated genotypically and phenotypically from the recognized species of the genus Novosphingobium. The isolate that has ginsenoside converting ability therefore represents a novel species, for which the name Novosphingobium ginsenosidimutans sp. nov. is proposed, with the type strain FW-6T (= KACC 16615T = JCM 18202T).

Published
2013
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32. The Rhododendron dauricum L. Flavonoids Exert Vasodilation and Myocardial Preservation.

Author

Zhang BN, Hou YL, Liu BJ, Liu QM, and Qiao GF

Abstract

Rhododendron dauricum L. is an ancient Chinese traditional herb. The pharmacological effects of R. dauricum extract have been shown in chronic tracheitis. The aim of this study was to investigate the cardiovascular effects of Rhododendron dauricum L. flavonoids (RF) on rats and its mechanisms. This study was performed in isolated vascular rings and a rat model of myocardial infarction and isolated myocytes. RF (0.5 - 4 mg/mL) induced a concentration-dependent relaxant effect on the phenylephrine (10(-5) M) and KCl (60 mM) contracted aortic rings, with or without intact endothelium. This effect was attenuated by pretreated with L-NAME (10(-5) M) and K(+) channel inhibitor 4 - AP (1 mM) and TEA (1 mM). The Ca(2+)-induced contraction and PE-induced contraction were obviously attenuated after pretreated with RF (2 mg/mL) for 30 min in Krebs solution, without Ca(2+), containing 10(-4) mol EGTA. KCl (60 mM) significantly increased the intracellular free Ca(2+) concentration ([Ca(2+)]i) and RF inhibited the changes induced by KCl in single cardiac myocytes. RF obviously prolonged the survival time of hypoxia mice pretreated with isoprenaline and reduced the myocardial infarction size in rat coronary artery ligation. These findings suggest that RF induces concentration-dependent vasodilation and myocardial preservation.

Published
2010

33. Sphingopyxis panaciterrae sp. nov., isolated from soil from ginseng field.

Author

Lee HW, Ten IL, Jung HM, Liu QM, Im WT, and Lee ST

Subjects
Base Composition, DNA, Bacterial genetics, Fatty Acids chemistry, Genes, Bacterial, Genes, rRNA, Korea, Nucleic Acid Hybridization, Phenotype, Phylogeny, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Sphingomonadaceae chemistry, Panax microbiology, Soil Microbiology, Sphingomonadaceae genetics, Sphingomonadaceae isolation & purification
Abstract

A Gram-negative, strictly aerobic, motile bacterial strain, designated Gsoil 124T, was isolated from a soil sample taken from a ginseng field in Pocheon Province (South Korea). The isolate contained Q-10 as the predominant lipoquinone, plus C18:1 7c and summed feature 4 (C16:1 6c and/or iso- C15:0 2-OH) as the major fatty acids. The G+C content of the genomic DNA was 68.1 mol%, and the major polar lipids consisted of sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, and phosphatidylethanolamine. A comparative 16S rRNA gene sequence analysis showed that strain Gsoil 124T was most closely related to Sphingopyxis chilensis (98.7%), Sphingopyxis alaskensis (98.2%), Sphingopyxis witflariensis (98.2%), Sphingopyxis taejonensis (98.0%), and Sphingopyxis macrogoltabida (97.6%). However, the DNA-DNA relatedness between strain Gsoil 124T and its phylogenetically closest neighbors was less than 22%. Thus, on the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 124T should be classified as representing a novel species in the genus Sphingopyxis, for which the name Sphingopyxis panaciterrae sp. nov. is proposed. The type strain is Gsoil 124T (=KCTC 12580T=LMG 24003T).

Published
2008

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