title: Degradation of intestinal glycoproteins by pathogenic Shigella flexneri.
abstract: Intestinal mucin glycoproteins were examined for their ability to sustain growth of pathogenic shigella. Inoculation of germfree cecal mucin glycoproteins with Shigella flexneri 4b resulted at 48 h in a 940-fold increase in the enteropathogen concentration. Investigation in vitro of enzymatic degradation by the pathogen led to the identification of a blood group B-degrading glycosidase produced by the bacteria. In in vivo experiments, fecal supernatants of mice monocontaminated with S. flexneri 4b contained an alpha-galactosidase active against the p-nitrophenyl-glycoside. This fecal alpha-galactosidase peaked 5 days after shigella contamination, showing 2.8 +/- 1.4 mU of enzyme activity per mg of protein. Contaminated fecal supernatants similarly destroyed the blood group B reactivity of cecal mucin glycoproteins. These data suggested that S. flexneri 4b could proliferate within ileocolonic environment by enzymatically degrading mucin glycoprotein sugars.
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism; D000818:Animals; D002432:Cecum / Q000032:analysis*; D006023:Glycoproteins / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D051379:Mice; D009077:Mucins / Q000378:metabolism*; D012763:Shigella flexneri / Q000378:metabolism*; D000519:alpha-Galactosidase / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D009077:Mucins; D006026:Glycoside Hydrolases; D000519:alpha-Galactosidase; D001616:beta-Galactosidase; D000118:Acetylglucosaminidase