The Experts below are selected from a list of 852 Experts worldwide ranked by ideXlab platform

Ludwig Jonas - One of the best experts on this subject based on the ideXlab platform.

  • effect of the lectins wheat germ Agglutinin wga and Ulex Europaeus Agglutinin uea i on the α amylase secretion of rat pancreas in vitro and in vivo
    Pancreas, 1998
    Co-Authors: Ulrike Mikkat, Ingo Damm, G Schroder, K Schmidt, C Wirth, Heike Weber, Ludwig Jonas
    Abstract:

    Lectins are able to bind to cholecystokinin (CCK) receptors and other glycosylated membrane proteins. The lectins wheat germ Agglutinin (WGA) and Ulex Europaeus Agglutinin (UEA-I) are used for affinity chromatography to isolate the highly glycosylated CCK-A receptor of pancreatic acinar cells. According to the working hypothesis that lectin binding to the CCK receptor should alter the ligand-receptor interaction, the effect of WGA and UEA-I on CCK-8-induced enzyme secretion was studied on isolated rat pancreatic acini in vitro. In vitro both lectins showed a dosage-dependent inhibition of CCK-8-induced alpha-amylase secretion of acini over 60 min. WGA showed a strong inhibitory effect on amylase secretion, approximately 40%, in vitro. UEA-I caused a smaller, but significant decrease, approximately 20%, in enzyme secretion of isolated acini. Additionally, both lectins inhibited cerulein/secretin- or cerulein-induced pancreatic secretion of rats in vivo, but not after secretin alone. The results are discussed with respect to a possible influence of both lectins on the interaction of CCK or cerulein with the CCK-A receptor.

  • effect of the lectins wheat germ Agglutinin wga and Ulex Europaeus Agglutinin uea i on the alpha amylase secretion of rat pancreas in vitro and in vivo
    Pancreas, 1998
    Co-Authors: Ulrike Mikkat, Ingo Damm, G Schroder, K Schmidt, C Wirth, Heike Weber, Ludwig Jonas
    Abstract:

    Lectins are able to bind to cholecystokinin (CCK) receptors and other glycosylated membrane proteins. The lectins wheat germ Agglutinin (WGA) and Ulex Europaeus Agglutinin (UEA-I) are used for affinity chromatography to isolate the highly glycosylated CCK-A receptor of pancreatic acinar cells. According to the working hypothesis that lectin binding to the CCK receptor should alter the ligand-receptor interaction, the effect of WGA and UEA-I on CCK-8-induced enzyme secretion was studied on isolated rat pancreatic acini in vitro. In vitro both lectins showed a dosage-dependent inhibition of CCK-8-induced alpha-amylase secretion of acini over 60 min. WGA showed a strong inhibitory effect on amylase secretion, approximately 40%, in vitro. UEA-I caused a smaller, but significant decrease, approximately 20%, in enzyme secretion of isolated acini. Additionally, both lectins inhibited cerulein/secretin- or cerulein-induced pancreatic secretion of rats in vivo, but not after secretin alone. The results are discussed with respect to a possible influence of both lectins on the interaction of CCK or cerulein with the CCK-A receptor.

Luis Izquierdo - One of the best experts on this subject based on the ideXlab platform.

  • The disruption of GDP-fucose de novo biosynthesis suggests the presence of a novel fucose-containing glycoconjugate in Plasmodium asexual blood stages
    Scientific Reports, 2016
    Co-Authors: Sílvia Sanz, Borja López-gutiérrez, Giulia Bandini, Sebastian Damerow, Sabrina Absalon, Rhoel R. Dinglasan, John Samuelson, Luis Izquierdo
    Abstract:

    Glycosylation is an important posttranslational protein modification in all eukaryotes. Besides glycosylphosphatidylinositol (GPI) anchors and N -glycosylation, O -fucosylation has been recently reported in key sporozoite proteins of the malaria parasite. Previous analyses showed the presence of GDP-fucose (GDP-Fuc), the precursor for all fucosylation reactions, in the blood stages of Plasmodium falciparum . The GDP-Fuc de novo pathway, which requires the action of GDP-mannose 4,6-dehydratase (GMD) and GDP-L-fucose synthase (FS), is conserved in the parasite genome, but the importance of fucose metabolism for the parasite is unknown. To functionally characterize the pathway we generated a PfGMD mutant and analyzed its phenotype. Although the labelling by the fucose-binding Ulex Europaeus Agglutinin I (UEA-I) was completely abrogated, GDP-Fuc was still detected in the mutant. This unexpected result suggests the presence of an alternative mechanism for maintaining GDP-Fuc in the parasite. Furthermore, PfGMD null mutant exhibited normal growth and invasion rates, revealing that the GDP-Fuc de novo metabolic pathway is not essential for the development in culture of the malaria parasite during the asexual blood stages. Nonetheless, the function of this metabolic route and the GDP-Fuc pool that is generated during this stage may be important for gametocytogenesis and sporogonic development in the mosquito.

Ulrike Mikkat - One of the best experts on this subject based on the ideXlab platform.

  • effect of the lectins wheat germ Agglutinin wga and Ulex Europaeus Agglutinin uea i on the α amylase secretion of rat pancreas in vitro and in vivo
    Pancreas, 1998
    Co-Authors: Ulrike Mikkat, Ingo Damm, G Schroder, K Schmidt, C Wirth, Heike Weber, Ludwig Jonas
    Abstract:

    Lectins are able to bind to cholecystokinin (CCK) receptors and other glycosylated membrane proteins. The lectins wheat germ Agglutinin (WGA) and Ulex Europaeus Agglutinin (UEA-I) are used for affinity chromatography to isolate the highly glycosylated CCK-A receptor of pancreatic acinar cells. According to the working hypothesis that lectin binding to the CCK receptor should alter the ligand-receptor interaction, the effect of WGA and UEA-I on CCK-8-induced enzyme secretion was studied on isolated rat pancreatic acini in vitro. In vitro both lectins showed a dosage-dependent inhibition of CCK-8-induced alpha-amylase secretion of acini over 60 min. WGA showed a strong inhibitory effect on amylase secretion, approximately 40%, in vitro. UEA-I caused a smaller, but significant decrease, approximately 20%, in enzyme secretion of isolated acini. Additionally, both lectins inhibited cerulein/secretin- or cerulein-induced pancreatic secretion of rats in vivo, but not after secretin alone. The results are discussed with respect to a possible influence of both lectins on the interaction of CCK or cerulein with the CCK-A receptor.

  • effect of the lectins wheat germ Agglutinin wga and Ulex Europaeus Agglutinin uea i on the alpha amylase secretion of rat pancreas in vitro and in vivo
    Pancreas, 1998
    Co-Authors: Ulrike Mikkat, Ingo Damm, G Schroder, K Schmidt, C Wirth, Heike Weber, Ludwig Jonas
    Abstract:

    Lectins are able to bind to cholecystokinin (CCK) receptors and other glycosylated membrane proteins. The lectins wheat germ Agglutinin (WGA) and Ulex Europaeus Agglutinin (UEA-I) are used for affinity chromatography to isolate the highly glycosylated CCK-A receptor of pancreatic acinar cells. According to the working hypothesis that lectin binding to the CCK receptor should alter the ligand-receptor interaction, the effect of WGA and UEA-I on CCK-8-induced enzyme secretion was studied on isolated rat pancreatic acini in vitro. In vitro both lectins showed a dosage-dependent inhibition of CCK-8-induced alpha-amylase secretion of acini over 60 min. WGA showed a strong inhibitory effect on amylase secretion, approximately 40%, in vitro. UEA-I caused a smaller, but significant decrease, approximately 20%, in enzyme secretion of isolated acini. Additionally, both lectins inhibited cerulein/secretin- or cerulein-induced pancreatic secretion of rats in vivo, but not after secretin alone. The results are discussed with respect to a possible influence of both lectins on the interaction of CCK or cerulein with the CCK-A receptor.

Sebastien Fort - One of the best experts on this subject based on the ideXlab platform.

  • efficient conjugation of oligosaccharides to polymer particles through furan maleimide diels alder reaction application to the capture of carbohydrate binding proteins
    ChemBioChem, 2017
    Co-Authors: Antoine Petrelli, Eric Samain, Stephanie Pradeau, Sami Halila, Sebastien Fort
    Abstract:

    Glycan-protein interactions play a crucial role in physiological and pathological events. Hence, improving the isolation of carbohydrate-binding proteins (i.e. lectins and anti-glycan antibodies) from complex media can not only lead to a better understanding of their function, but also provides solutions for public health issues, such as water contamination or the need for universal blood plasma. Herein, we report a rapid and efficient method to produce carbohydrate-based affinity adsorbents combining enzymatic synthesis and metal-free click chemistry. Simple as well as complex glycans (maltose, blood group antigens A, B and H) were readily modified by the addition of a furyl group at their reducing end without the need for protecting groups and then efficiently conjugated to maleimide-activated Sepharose particles via a Diels-Alder reaction. These neoglycoconjugates showed high efficiency for the purification of lectins (Concanavalin A and Ulex Europaeus Agglutinin) as well as for the capture of anti-A and anti-B blood group antibodies, opening new prospects for glycoproteomics and for the development of universal blood plasma.

Sílvia Sanz - One of the best experts on this subject based on the ideXlab platform.

  • The disruption of GDP-fucose de novo biosynthesis suggests the presence of a novel fucose-containing glycoconjugate in Plasmodium asexual blood stages
    Scientific Reports, 2016
    Co-Authors: Sílvia Sanz, Borja López-gutiérrez, Giulia Bandini, Sebastian Damerow, Sabrina Absalon, Rhoel R. Dinglasan, John Samuelson, Luis Izquierdo
    Abstract:

    Glycosylation is an important posttranslational protein modification in all eukaryotes. Besides glycosylphosphatidylinositol (GPI) anchors and N -glycosylation, O -fucosylation has been recently reported in key sporozoite proteins of the malaria parasite. Previous analyses showed the presence of GDP-fucose (GDP-Fuc), the precursor for all fucosylation reactions, in the blood stages of Plasmodium falciparum . The GDP-Fuc de novo pathway, which requires the action of GDP-mannose 4,6-dehydratase (GMD) and GDP-L-fucose synthase (FS), is conserved in the parasite genome, but the importance of fucose metabolism for the parasite is unknown. To functionally characterize the pathway we generated a PfGMD mutant and analyzed its phenotype. Although the labelling by the fucose-binding Ulex Europaeus Agglutinin I (UEA-I) was completely abrogated, GDP-Fuc was still detected in the mutant. This unexpected result suggests the presence of an alternative mechanism for maintaining GDP-Fuc in the parasite. Furthermore, PfGMD null mutant exhibited normal growth and invasion rates, revealing that the GDP-Fuc de novo metabolic pathway is not essential for the development in culture of the malaria parasite during the asexual blood stages. Nonetheless, the function of this metabolic route and the GDP-Fuc pool that is generated during this stage may be important for gametocytogenesis and sporogonic development in the mosquito.