title: Inhibition of Escherichia coli heat-labile enterotoxin by neoglycoprotein and anti-lectin antibodies which mimic GM1 receptor.
abstract: Escherichia coli producing heat-labile enterotoxin is responsible for numerous cases of diarrhea worldwide, leading to considerable morbidity and mortality. The B subunits of this toxin are responsible for the binding to the receptor, the complex ganglioside GM1 which has galactose as its terminal sugar. In this study we showed that analogs of galactose (gal) and N-acetylgalactosamine (GalNAc) interfere with the binding of heat-labile toxin to GM1. Antibodies to lectins which mimic sugar structures and neoglycoprotein were employed. These compounds were able to inhibit heat-labile toxin activity efficiently in Vero cells: 37 microg of IgG-enriched fraction from an antiserum inhibited up to 70% of this activity, and 50% of the binding of heat-labile toxin to GM1. Neoglycoprotein was more efficient than antibodies, since 2.5 microg of this ligand completely abolished the activity of heat-labile toxin on Vero cells. These data suggest that these molecules could be developed for prophylaxis and diagnosis of diarrhea caused by heat-labile toxin.
authors.affiliation: Laboratório Especial de Microbiologia, Instituto Butantan, São Paulo, Brazil.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Menezes
authors.forename: Jackeline
authors.initials: J
authors.lastname: Amianti
authors.forename: Hebert S
authors.initials: HS
authors.lastname: Harayama
authors.forename: Paula C M
authors.initials: PC
authors.lastname: Koga
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Trabulsi
authors.forename: Roxane M F
authors.initials: RM
authors.lastname: Piazza
mesh_terms: D000116:Acetylgalactosamine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002522:Chlorocebus aethiops; D004768:Enterotoxins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005690:Galactose / Q000031:analogs & derivatives / Q000494:pharmacology; D006023:Glycoproteins / Q000494:pharmacology*; D037102:Lectins / Q000276:immunology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014709:Vero Cells
chemical_list: D000906:Antibodies; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D006023:Glycoproteins; D037102:Lectins; D011956:Receptors, Cell Surface; C034993:ganglioside receptor; C027538:heat-labile enterotoxin, E coli; D000116:Acetylgalactosamine; D005690:Galactose