Search

Your search keyword '"Liu, Qing-mei"' showing total 216 results
Start Over Author "Liu, Qing-mei"
216 results on '"Liu, Qing-mei"'

53. 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

55. 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
Full Text
View/download PDF

76. 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
Full Text
View/download PDF

78. 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.

79. 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
View/download PDF

80. 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
View/download PDF

81. 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
View/download PDF

82. 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
View/download PDF

83. 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
View/download PDF

84. 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
View/download PDF

85. 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
View/download PDF

86. 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
View/download PDF

87. 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
View/download PDF

88. 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
View/download PDF

89. 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
View/download PDF

90. 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
View/download PDF

91. 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
View/download PDF

92. 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
View/download PDF

93. 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
View/download PDF

94. PAF exerts a direct apoptotic effect on the rat H9c2 cardiomyocytes in Ca2+-dependent manner

Author

Zhao, Dan, Chu, Wen-Feng, Wu, Ling, Li, Jing, Liu, Qing-Mei, Lu, Yan-Jie, Qiao, Guo-Fen, Wang, Zhi-Guo, Zhang, Zhi-Ren, and Yang, Bao-Feng

Subjects
*PLATELET activating factor, *APOPTOSIS, *HEART cells, *INTRACELLULAR calcium, *ISCHEMIA, *MITOGEN-activated protein kinases, *ENZYME inhibitors, *LABORATORY rats
Abstract

Abstract: Background: Previous studies suggested that platelet-activating factor (PAF) plays an important role in ischemic diseases. Apoptosis has been implicated in myocardial infarction-related cell death. The present study was designed to determine whether PAF could induce apoptosis in cardiac myocytes and the underlying mechanisms by which PAF causes apoptosis. Methods: H9c2 cardiac myocytes were used to investigate the effect of PAF on intracellular calcium concentration, cell viability and cell apoptosis. Signaling pathway of caspase-3, cytochrome c and MAPK (ERK, JNK, p38) was determined during the PAF induced apoptosis. Results: First, our results showed that treatment of H9c2 cardiomyocytes with PAF (0.2 to 20 µM) caused apoptosis in these cells and the apoptotic process was suppressed by either BN52021 (an antagonist of PAF receptor) or BAPTA/AM (an intracellular Ca2+ chelator), suggesting an involvement of PAF and its receptor mediated calcium-dependent signaling. Second, we found that activity of p38-MAPK (mitogen-activated protein kinase) and caspase-3 was elevated in the cells treated with PAF, without altering activity of ERK and JNK, and that PAF-induced enhancement of caspase-3 activity was attenuated by application of either BAPTA/AM or SB203580 (p38 inhibitor). Furthermore, PAF-induced apoptosis and release of cytochrome c from mitochondria was blunted by SB203580, and PAF-induced enhancement of p38 activity was also attenuated by BAPTA/AM. Conclusion: Our data implicate that a PAF and its receptor in triggering apoptosis occurs in cultured H9c2 cardiac myocytes via a calcium-dependent p38 MAPK activated cytochrome c/caspase-3 apoptosis signaling pathway. [Copyright &y& Elsevier]

Published
2010
Full Text
View/download PDF

95. [Research on the variation regularity of effluent from the leachate reverse osmosis concentrate recirculation].

Author

Wang DM, Liu D, Liu QM, Tao LX, and Liu Y

Subjects
Adsorption, Bioreactors, Carbon analysis, Filtration, Metals, Heavy analysis, Nitrogen analysis, Osmosis, Garbage, Water Pollutants, Chemical analysis
Abstract

To provide certain theoretical basis for selecting recirculation landfill scientifically and reasonably, the variation regularity of recirculation effluent from the landfill columns in three different years was studied. By using leachate reverse osmosis concentrate from a refuse landfill in Chengdu, the recirculation experiments were carried out in three landfill columns filled with garbage in 1, 5 and 15 landfill ages respectively. The variation regularity of pH, total organic carbon, ammonia nitrogen, nitrate nitrogen and heavy metals of recirculation effluent was researched. It showed that the one-year landfill column with a favorable ability of removing nitrate nitrogen and degradation rate of nitrate nitrogen reaching above 88% was in the stage of producing methanation, but the concentration of organic matter and ammonia nitrogen of the effluent is higher and changes in the parameters mainly depend on the biological function. The five-year landfill column without typical features of mineralized refuse and with relatively poor adsorption capacity and biological effects, as well as removal capacity of organic matter, salinity, Cr and Ni approaches stabilization. The fifteen-year landfill column has high capability of adsorption, complexing, as well as organic matter, salinity, Cr and Ni removal, and the removal rate at the initial stage reaches 90%, 78%, 93% and 78%, respectively, but the recirculation process and progress need to be controlled when the rate approaches or reaches the adsorption capacity.

Published
2014

96. 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
Full Text
View/download PDF

97. 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
Full Text
View/download PDF

98. Sphingomonas ginsengisoli sp. nov. and Sphingomonas sediminicola sp. nov.

Author

An DS, Liu QM, Lee HG, Jung MS, Kim SC, Lee ST, and Im WT

Subjects
Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Fatty Acids analysis, Glycosphingolipids analysis, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Republic of Korea, Sequence Analysis, DNA, Sphingomonas genetics, Sphingomonas isolation & purification, Ubiquinone analysis, Geologic Sediments microbiology, Panax microbiology, Phylogeny, Soil Microbiology, Sphingomonas classification
Abstract

Two novel bacteria, designated strains Gsoil 634(T) and Dae 20(T), were isolated in South Korea from soil of a ginseng field and freshwater sediment, respectively and were characterized by a polyphasic approach to clarify their taxonomic positions. Phylogenetic analysis based on 16S rRNA gene sequences indicated that, although they probably represented two distinct species (indicated by a sequence similarity of 96.6 %), both strain Gsoil 634(T) and strain Dae 20(T) belonged to the genus Sphingomonas and were most closely related to 'Sphingomonas humi' PB323 (97.8 % and 96.7 % sequence similarity, respectively), Sphingomonas kaistensis PB56(T) (96.8 % and 96.7 %), Sphingomonas astaxanthinifaciens TDMA-17(T) (96.6 % and 95.4 %) and Sphingomonas jaspsi TDMA-16(T) (95.6 % and 95.8 %). For both novel strains, the major ubiquinone was Q-10, the major polyamine was homospermidine, the major cellular fatty acids included summed feature 7 (C(18 : 1)ω7c, C(18 : 1)ω9t and/or C(18 : 1)ω12t), C(17 : 1)ω6c and C(16 : 0), and the polar lipids included sphingoglycolipid. These chemotaxonomic data supported the affiliation of both strains to the genus Sphingomonas. However, the DNA-DNA relatedness value between strain Gsoil 634(T) and 'Sphingomonas humi' PB323(T) was 31 %. Moreover, the results of physiological and biochemical tests allowed the phenotypic differentiation of strains Gsoil 634(T) and Dae 20(T) from established members of the genus Sphingomonas. Based on these data, the two isolates represent two novel species in the genus Sphingomonas, for which the names Sphingomonas ginsengisoli sp. nov. (type strain Gsoil 634(T) = KCTC 12630(T) = DSM 18094(T) = LMG 23739(T)) and Sphingomonas sediminicola sp. nov. (type strain Dae 20(T)  = KCTC 12629(T) = DSM 18106(T) = LMG 23592(T)) are proposed.

Published
2013
Full Text
View/download PDF

99. [The research progress of foamy virus Bet protein].

Author

Gao Y, Sun Y, Li Z, Liu QM, Liu WH, and He XH

Subjects
Animals, Gene Expression Regulation, Viral, Humans, Retroviridae Infections immunology, Retroviridae Proteins genetics, Spumavirus genetics, Retroviridae Infections virology, Retroviridae Proteins metabolism, Spumavirus metabolism
Abstract

Foamy virus can establish lifelong persistent infection in mammal hosts without inducing diseases. Such special characteristic stimulates the interests of researchers. As reported, the accessory protein Bet of foamy virus could regulate the gene expression and infection cycle of foamy virus and take part in the generation of chronic viral infection. And also, Bet might prevent the host cellular defense factor APO-BEC3 from interfering the replication of virus and play a role in maintaining viral persistent infection. In order to elucidate the roles of Bet in the foamy virus replication and infection, this review summarized the research progress of Bet protein reported in recent years.

Published
2012

100. [Optimization of supercritical fluid extraction of ursolic acid from follum eriobotryae by response surface methodology].

Author

Zhang HE, Zhang FQ, Wang CX, and Liu QM

Subjects
Analysis of Variance, Anti-Inflammatory Agents, Non-Steroidal isolation & purification, Carbon Dioxide, Chromatography, High Pressure Liquid methods, Pressure, Temperature, Time Factors, Triterpenes analysis, Ursolic Acid, Chromatography, Supercritical Fluid methods, Plant Leaves chemistry, Plants, Medicinal chemistry, Rosaceae chemistry, Triterpenes isolation & purification
Abstract

Objective: To optimize the conditions for extracting ursolic acid from Follum eriobotryae with supercritical fluid extration (SFE)., Methods: The contents of ursolic acid in the extracts were determined by HPLC. Based on single factor experiment and response surface methodology, a mathematical model for SFE of ursolic acid was built., Results: The result showed that the optimum condition paremeters were as follows: temperature 61.6 degrees C, extraction pressure 25.8 MPa, dynamic extraction time 40 min. Under these conditions, theoretical extraction rate of ursolic acid was 3.96 mg/g., Conclusion: The eptimal process is reliable.

Published
2011

Catalog

Books, media, physical & digital resources
See catalog results