Gustavo A. Nores

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The lectin from the common mushroom Agaricus bisporus, the most popular edible species in Western countries, has potent antiproliferative effects on human epithelial cancer cells, without any apparent cytotoxicity. This property confers to it an important therapeutic potential as an antineoplastic agent. The three-dimensional structure of the lectin was(More)
Epidermal growth factor- (EGF) dependent tyrosine phosphorylation of the EGF receptor was inhibited by the exogenous addition of GM3 to a membrane preparation and to purified EGF receptor adsorbed to antireceptor-antibody-Sepharose (Bremer, E. G., Schlessinger, J., and Hakomori, S. (1986) J. Biol. Chem. 261, 2434-2440). A specific functional correlation(More)
Epithelial cancer cells show increased cell surface expression of mucin antigens with aberrant O-glycosylation, notably type I core (Galbeta1-3GalNAcalpha), termed Thomsen-Friedenreich disaccharide (TFD), a chemically well-defined carbohydrate antigen with a proven link to malignancy. Several TFD-binding proteins influence the proliferation of cells to(More)
Glycans are a class of molecules with high structural variability, frequently found in the plasma membrane facing the extracellular space. Because of these characteristics, glycans are often considered as recognition molecules involved in cell social functions, and as targets of pathogenic factors. Induction of anti-glycan antibodies is one of the early(More)
High antibody affinity has been proposed as a disease determinant factor in neuropathies associated with anti-GM1 antibodies. An experimental model of Guillain-Barré syndrome, induced by immunization of rabbits with bovine brain gangliosides or GM1, was described recently (Yuki et al. [2001] Ann. Neurol. 49:712-720). We searched plasma from these rabbits,(More)
Gangliosides are glycolipids mainly present at the plasma membrane (PM). Antibodies to gangliosides have been associated with a wide range of neuropathy syndromes. Particularly, antibodies to GM1 ganglioside are present in patients with Guillain-Barré syndrome (GBS). We investigated the binding and intracellular fate of antibody to GM1 obtained from rabbits(More)
Galbeta1-3GalNAc (T-disaccharide) and related molecules were assayed to describe the structural requirements of carbohydrates to bind Agaricus bisporus lectin (ABL). Results provide insight into the most relevant regions of T-disaccharide involved in the binding of ABL. It was found that monosaccharides bind ABL weakly indicating a more extended(More)
The primary interaction between purified Agaricus bisporus lectin (ABL) and human IgA subclasses was studied by ABL-affinity chromatography, dot blot assay and competitive enzyme-lectin assay, considering that ABL could be an alternative tool for detection of IgA1 O-glycans. Both secretory IgA subclasses bound to ABL-Sepharose and the IgA2 subclass (which(More)
In previous studies, an IgM monoclonal antibody (M2590), established after immunization of C57BL/6 mice with syngeneic B16 melanoma cells, was found to react with melanoma cells, but not with various normal cells and tissues (Taniguchi, M., and Wakabayashi, S., Jpn. J. Cancer Res., 75:418-426, 1984). The structure defined by this antibody was identified as(More)
Two types of modified GM3 strongly alter EGF-dependent phosphorylation of the EGF receptor in opposite directions, i.e., de-N-acetyl-GM3 (amino-GM3; NeuNH2 alpha 2----3Gal beta 1----4Glc beta 1----1 Ceramide) strongly promotes tyrosine phosphorylation of the EGF receptor of A431 cells, while lyso-GM3 (NeuNAc alpha 2----3Gal beta 1----4 Glc beta----1(More)