• Title/Summary/Keyword: Glycoconjugates

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Evaluation of chemopreventive effects of Thymoquinone on cell surface glycoconjugates and cytokeratin expression during DMBA induced hamster buccal pouch carcinogenesis

  • Rajkamal, G.;Suresh, K.;Sugunadevi, G.;Vijayaanand, M.A.;Rajalingam, K.
    • BMB Reports
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    • v.43 no.10
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    • pp.664-669
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    • 2010
  • The present study aimed to investigate the membrane stabilizing effect of Thymoquinone (TQ) on cell surface glycoconjugates and cytokeratin expression against DMBA induced hamster buccal pouch carcinogenesis. 0.5% DMBA painting (three times per week) in hamster buccal pouches for 14 weeks resulted in the formation of well developed oral squamous cell carcinoma. We observed 100% tumor formation with marked abnormalities of glycoconjugates status in tumor bearing hamsters as compared to control animals. Oral administration of TQ at a dose of 30 mg/kg body weight, to DMBA painted hamsters on alternate days for 14 weeks, reduced the tumor formation as well as protected the levels of cell surface glycoconjugates in DMBA painted hamsters. The present study thus suggests that TQ has potent chemopreventive efficacy as well as protected the abnormalities on cell surface glycoconjugates during DMBA induced hamster buccal pouch carcinogenesis.

MGrid: A Molecular Simulation Grid system (MGrid: 분자 시뮬레이션 그리드 시스템)

  • Jeong Karp-Joo;Lee Jong-Hyun;Cho Kum-Won;Jung Seun-Ho;Hwang Sun-Tae;Heo Dae-Young;Choi Young-Jin
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.7
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    • pp.380-389
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    • 2006
  • In this paper, we present the MGrid system and its application for the construction of the Glycoconjugates simulation database called e-Glycoconjugates. The MGrid system is an integrated molecular simulation grid system for computing, databases, and analyses. For e-Glycoconjugates, we have been constructing the simulation database for 2,000 glycan chains and 100 glycoproteins until 2008. In this paper, we present the goal, architecture, and current implementation status of the MGrid system, and e-Glycoconjugates.

Ginseng-derived type I rhamnogalacturonan polysaccharide binds to galectin-8 and antagonizes its function

  • Yi Zheng;Yunlong Si;Xuejiao Xu;Hongming Gu;Zhen He;Zihan Zhao;Zhangkai Feng;Jiyong Su;Kevin H. Mayo;Yifa Zhou;Guihua Tai
    • Journal of Ginseng Research
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    • v.48 no.2
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    • pp.202-210
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    • 2024
  • Background: Panax ginseng Meyer polysaccharides exhibit various biological functions, like antagonizing galectin-3-mediated cell adhesion and migration. Galectin-8 (Gal-8), with its linker-joined N- and C-terminal carbohydrate recognition domains (CRDs), is also crucial to these biological processes, and thus plays a role in various pathological disorders. Yet the effect of ginseng-derived polysaccharides in modulating Gal-8 function has remained unclear. Methods: P. ginseng-derived pectin was chromatographically isolated and enzymatically digested to obtain a series of polysaccharides. Biolayer Interferometry (BLI) quantified their binding affinity to Gal-8, and their inhibitory effects on Gal-8 was assessed by hemagglutination, cell migration and T-cell apoptosis. Results: Our ginseng-derived pectin polysaccharides consist mostly of rhamnogalacturonan-I (RG-I) and homogalacturonan (HG). BLI shows that Gal-8 binding rests primarily in RG-I and its β-1,4-galactan side chains, with sub-micromolar KD values. Both N- and C-terminal Gal-8 CRDs bind RG-I, with binding correlated with Gal-8-mediated function. Conclusion: P. ginseng RG-I pectin β-1,4-galactan side chains are crucial to binding Gal-8 and antagonizing its function. This study enhances our understanding of galectin-sugar interactions, information that may be used in the development of pharmaceutical agents targeting Gal-8.

Lectin Histochemistry on the Effects of Smoking on Glycoconjugates of Rat Sebaceous Glands (흡연이 흰쥐 복부 피지샘의 glycoconjugates에 미치는 영향에 대한 lectin 조직화학)

  • Jo, Un-Bock;Jeong, Gil-Nam
    • Journal of Life Science
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    • v.18 no.11
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    • pp.1543-1550
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    • 2008
  • We studied the effects of smoking, which is one of indoor-environmental pollutants and related to various cancers, on glycoconjugates of rat sebaceous glands with the lectin histochemistry. To investigate the effects of smoking on glycoconjugates, male Sprague-Dawley rats were exposed to tabacco smoke for 10 minutes per day in an inhalation chamber for 1, 2, 3, and 5 days with active and passive exposure. For the structure of sebaceous glands we used PAS reaction, and for the glycoconjugates binding pattern 9 biotinylated lectins (DBA, SBA, PNA, BSL-1, WGA, RCA-1, UEA-1, Con A, and LCA) were used. Some remarkable changes, such as the decrease in the size of sebaceous glandular acini, the destruction of upper portion of sebaceous glands, vacuolation of central portion of sebocytes, and the immature sebaceous glandular acini were seen in the smoke-exposed rats. In the control rats, basal cells were stained with BSL-1, PNA and WGA, but the stronger reaction was founded in BSL-1 binding. Also, sebocytes were stained with PNA, WGA, Con A, BSL-1 and SBA, but stronger reactions were founded in PNA and Con A stainings. Specific changes in the lectin binding patterns were also observed in the smoke-exposed rats. In the basal cells of exposed rats, PNA binding increased, BSL-1 decreased but returned to control level, and WGA disappeared. Plus, immature glandular acini, which were not found in the control rats, were stained PNA, Con A and BSL-1, but the stronger reaction were founded in PNA and Con A binding. In conclusion, it was assumed that the tabacco smoke seriously effected on the structure and glycoconjugates metabolism of sebaceous glands.

Prelectin Histochemistry for Effects of N-Nitrosodimethylamine on Glycoconjugates in the Rat Lingual Glands (N-Nitrosodimethylamine이 흰쥐 설선의 Glycoconjugates에 미치는 영향에 대한 Prelectin 조직화학)

  • 조운복;조기진
    • Journal of Life Science
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    • v.8 no.5
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    • pp.509-519
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    • 1998
  • The effect of N-Nitrosodimethylamine(NDMA) on the glycoconjugates of rat lingual salivary gland was examined by prelectin histochemical methods. Sprague-Dawley rats weighing about 250-300g were divided into control and experimental groups. Each rat of experimental groups was administrated NDMA(17mg/kg) orally and sacrificed in 3, 6, 12, 24, 48, 72, 96 and 120 hours after NDMA administration. The regional differences and change of glycoco-njugates were elucidated by prelectin histochemical methods, such as periodic acid Schiff's(PAS) reaction, alcian blue (AB) pH 2.5, AB pH 0.4, AB pH 2.5-PAS, aldehyde fuchsin(AF) pH 1.7-AB pH 2.5 and high iron diamine(HID)-AB pH 2.5 staining. The major morphological changes in the von Ebner’s gland of NDMA administrated groups were withering and des-truction of serous acini, diminution and disappearance of cytoplasmic granules and vacuolation in cytoplasm of serous cells, and mucinous changes of duct epithelial cells. These changes were noted in NDMA administrated groups for 12 to 72 hours. In the lingual mucous gland of NDMA administrated groups, the major morphological changes were enlargement, fusion and destruction of mucous acini, loss of cytoplasmic granules and vacuolated generation in cytop-lasm of mucous cells, and mucinous change of duct epithelial cells. These changes were severe in NDMA administra-ted groups for 12 to 72 hours. In NDMA administrated groups of lingual von Ebner's gland for 12 and 72 hours, the neutral glycoconjugates be-come diminished remarkably compared to the control group. The decreased amount of neutral glycoconjugates tended to be gradually recovered from 96 hours group. The acidic glycoconjugates which were not detected in control group were found in a few serous cells of these gland of NDMA administrated groups for 6 to 48 hours and 120 ho-urs. The remarkable decrease of neutral and acidic glycoconjugates was observed in the lingual mucous glands 3, 24 and 48 hours after NDMA administration, and the striking decrease of acidic glycoconjugates was found in 72 hours groups. Among acidic glycoconjugates, sulfated glycoconjugates tended to decrease in NDMA administrated groups for 72 hours, while sialic glycoconjugates were increased in NDMA administrated groups for 3, 12 and 48 hours.

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Regional Difference in Distribution of Glycoconjugates in Mouse Epididymis (생쥐 부정소 부위별 당쇄 분포의 차이)

  • 계명찬
    • Development and Reproduction
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    • v.5 no.2
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    • pp.167-173
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    • 2001
  • To characterize the difference in glycoconjugates of mouse epididymis, lectin labeling of the tissue section was conducted using Ulex europaeus agglutinin I(UEA I), succinylated wheat germ agglutinin(sWGA), and Griffonia simplicifolia lectin-I(GSL-I). UEA I which binds to outer $\alpha$-L-fucose residue that is a terminal sugar of the side chain branched from oligosaccharide chain gave the labeling in the proximal caput epithelia exclusively. Lumen was commonly labeled in all of the organ. It suggested that the glycoconjugates bearing outer $\alpha$ -L-fucose residue were largely expressed in the initial segments ot epididymis and subjected to secretion. GSL-I which binds to terminal $\alpha$ -D-galactosyl residue of glycoconjugates gave the labeling in the cytoplasm of clear cells and basal cells, and cilia in corpus and cauda regions but not in the caput region. There was no vast difference in labeling pattern by sWGA which binds to N-acetyl-glucosamine residue among the epididymal regions. Clear cells in corpus and cauda epithelia showed more intense labeling by sWGA compared to principal cells, suggesting the functional specialization of this type of cells. The labeling intensities of luminal content by UEA I and sWGA decreased in cauda region compared to corpus region suggesting the presence of enzymatic activities responsible for processing the $\alpha$-L-fucose and N-acetyl-glucosamine residues from secreted glycoconjugates. In summary, the difference in glycoconjugates bearing the $\alpha$-L-fucose, $\alpha$-D-galactose, and N-acetyl-glucosamine residues according to the type of epithelial cells and epididymal segments suggests functional specialization and different roles of each segment in the processing of sperm surface antigens during the epididymal transit.

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Effect of Luteolin on the Levels of Glycoproteins During Azoxymethane-induced Colon Carcinogenesis in Mice

  • Pandurangan, Ashok Kumar;Dharmalingam, Prakash;Sadagopan, Suresh Kumar Ananda;Ganapasam, Sudhandiran
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1569-1573
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    • 2012
  • Luteolin (LUT), a bioflavonoid has been used as a chemopreventive agent world-wide against chemically induced cancer. Hence we designed an experiment to assess chemopreventive action of LUT on lipid peroxidation (LPO) and glycoconjugates in azoxymethane (AOM)-induced colon carcinogenesis. Colon cancer was induced by 15 mg/body kg. body weight of AOM and administration of LUT (at the dose of 1.2 mg/kg. body weight) was till end of the study. Analysis of lipid peroxidative end products such as protein carbonyl (PC), malonadehyde (MDA) and conjucated dienes (CD) demonstrated significant increase in in AOM-induced animals with reduction by LUT (p<0.05). Increased levels of glycoconjugates such as hexose, hexosamine, sialic acid, fucose and mucoprotein were analyzed in serum and colon tissues examined histopathologically by periodic acid Schiff's (PAS) staining were also reversed by LUT l(p<0.05). The secondary marker of colon cancer mucin depleted foci (MDF) was assessed in control and experimental group of animals. A characteristic increase of MDF was observed in AOM-induced colon cancer animals. Treatment with LUT decreased the incidence of MDF. These results suggest that LUT alters the expression of glycoconjugates and suppress colon cancer. Hence, we speculate that LUT can be used as a chemopreventive agent to treat colon cancer.

Effect of Low Dose Mutagens on Adoptive Response and Plasma Membrane Glycoconjugates in Sarcoma 180 Cells

  • Lee, Jong Hwa;Choi, Eun Sili;Oh, Kyu Seon;Lee, Dong Wook;Chang, Jeong Hyun;Um, Kyung Il
    • Animal cells and systems
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    • v.4 no.3
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    • pp.293-297
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    • 2000
  • The present investigation was performed to elucidate the effect of pretreatment with low dose ultraviolet radiation (UV) and ethyl methanesulfonate (EMS) on cell survival by trypan blue dye exclusion method and plasma membrane glycoconjugates by lectin-cytochemistry in sarcoma 180 (S180) cells. Pretreatment with 2 J/$m^2$ UV or 2 mM EMS increased the percentage of survival of cells subsequently treated with high dose UV (10 or 20 J/$m^2$) or EMS (10 or 20 mM), respectively. Staining intensity of concanavalin A (Con A) of the cells pretreated with 2J/$m^2$ UV or 2 mM EMS and subsequently treated with 10 or 20 mM EMS was stronger than that of the cellstreated with 10 or 20 mM EMS. These results suggest that there is an adaptive response on cell survival to EMS or UV in S180 cells. And the results show a change in mannose-containing glycoconjugates of plasma membrane in S180 cells pretreated with EMS or UV and subsequently treated with EMS.

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Molecular Cloning and Characterization of a Novel Exo-β-1,3-Galactanase from Penicillium oxalicum sp. 68

  • Zhou, Tong;Hu, Yanbo;Yan, Xuecui;Cui, Jing;Wang, Yibing;Luo, Feng;Yuan, Ye;Yu, Zhenxiang;Zhou, Yifa
    • Journal of Microbiology and Biotechnology
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    • v.32 no.8
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    • pp.1064-1071
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    • 2022
  • Arabinogalactans have diverse biological properties and can be used as pharmaceutical agents. Most arabinogalactans are composed of β-(1→3)-galactan, so it is particularly important to identify β-1,3-galactanases that can selectively degrade them. In this study, a novel exo-β-1,3-galactanase, named PoGal3, was screened from Penicillium oxalicum sp. 68, and hetero-expressed in P. pastoris GS115 as a soluble protein. PoGal3 belongs to glycoside hydrolase family 43 (GH43) and has a 1,356-bp gene length that encodes 451 amino acids residues. To study the enzymatic properties and substrate selectivity of PoGal3, β-1,3-galactan (AG-P-I) from larch wood arabinogalactan (LWAG) was prepared and characterized by HPLC and NMR. Using AG-P-I as substrate, purified PoGal3 exhibited an optimal pH of 5.0 and temperature of 40℃. We also discovered that Zn2+ had the strongest promoting effect on enzyme activity, increasing it by 28.6%. Substrate specificity suggests that PoGal3 functions as an exo-β-1,3-galactanase, with its greatest catalytic activity observed on AG-P-I. Hydrolytic products of AG-P-I are mainly composed of galactose and β-1,6-galactobiose. In addition, PoGal3 can catalyze hydrolysis of LWAG to produce galacto-oligomers. PoGal3 is the first enzyme identified as an exo-β-1,3-galactanase that can be used in building glycan blocks of crucial glycoconjugates to assess their biological functions.