Glycoprotein Degradation in the Blind Loop Syndrome

Prizont, Roberto

doi:10.1172/jci110040

Cited by 20 publications

(9 citation statements)

References 23 publications

(15 reference statements)

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“…The free galactose could then be utilized by the pathogen for metabolism, energy, and growth. Our previous experiments with blind loop animals appear to corroborate this scheme (19). Hence, radioactively labeled oligosaccharide chains of glycoproteins, incubated with colonic bacteria obtained from blind loop sacs, resulted in the production of labeled short-chain fatty acids.…”

Section: Discussionsupporting

confidence: 61%

“…Studies performed by Hoskins with feces of conventional rats and normal humans have clearly shown that some of the fecal microflora remove sugars from hog gastric mucin by action of blood group-degrading enzymes (8)(9)(10). We have similarly identified glycosidases of bacterial origin in cecal contents of conventional animals and bacterially contaminated contents from surgically created jejunal self-filling blind loops (19,20). These studies suggested that bacterial glycosidases allow fecal or colonic bacteria to obtain nutrient sugars from intestinal glycoproteins.…”

mentioning

confidence: 58%

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Degradation of intestinal glycoproteins by pathogenic Shigella flexneri

Prizont¹

1982

Infect Immun

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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.

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Section: Discussionsupporting

confidence: 61%

mentioning

confidence: 58%

Degradation of intestinal glycoproteins by pathogenic Shigella flexneri

Prizont¹

1982

Infect Immun

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“…Their extracellular glycosidases are also capable of altering surface antigenic carbohydrates on bacterial cell walls (40) as well as on erythrocyte membranes (41). Comparable effects on membrane glycolipids and glycoproteins of the gut mucosa could lead to alterations of attachment sites for toxins and bacteria as well as damage to brush border enzymes in bacterial overgrowth syndromes (42). These glycosidases may also contribute to the activation of mutagens by deconjugation of ingested plant glycosides (43,44).…”

Section: Discussionmentioning

confidence: 99%

Mucin degradation in human colon ecosystems. Isolation and properties of fecal strains that degrade ABH blood group antigens and oligosaccharides from mucin glycoproteins.

Hoskins¹,

Agustines²,

McKee³

et al. 1985

J. Clin. Invest.

299

193

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We previously reported that the oligosaccharide chains of hog gastric mucin were degraded by unidentified subpopulations numbering 1% of normal human fecal bacteria. Here we report on the enzyme-producing properties of five strains of mucin oligosaccharide chain-degrading bacteria isolated from feces of four healthy subjects. Four were isolated from the greatest fecal dilutions yielding mucin side chain-degrading activity in culture, and thus were the numerically dominant side chain-degrading bacteria in their respective hosts. Three were Ruminococcus strains and two were Bifidobacterium strains. Two Ruminococcus torques strains, IX-70 and VIII-239, produced blood group A-and H-degrading a-glycosidase activities, sialidase, and the requisite jl-glycosidases; these strains released >90% of the anthrone-reacting hexoses from hog gastric mucin during growth in culture. The Bifidobacterium strains lacked A-degrading activity but were otherwise similar, these released 60-80% of the anthrone-reacting hexoses but not the A antigenic structures from hog gastric mucin. Only Ruminococcus AB strain VI-268 produced blood group B-degrading a-galactosidase activity, but this strain lacked ,5-N-acetyl exosaminidases to complete degradation of B antigenic chains. When this strain was co-cultured with a strain that produced jl-N-acetylhexosaminidases, release of hexoses from blood group B salivary glycoprotein increased from 50 to >90%, and bacterial growth was enhanced. The glycosidases required for side chain degradation were produced by these strains in the absence of mucin substrate, and a substantial fraction of each activity in stationary phase cultures was extracellular. In contrast, none of 16 other fecal Bacteroides, Escherichia coli, Streptococcus faecalis, and Bifidobacterium strains produced ABH blood group-degrading enzymes; other glycosidases produced by these strains were predominantly cell bound except for extracellular j-N-acetylhexosaminidases produced by the five S. faecalis strains.We conclude that certain Bifidobacterium and Ruminococcus strains are numerically dominant populations degrading mucin oligosaccharides in the human colon due to their constitutive production of the requisite extracellular glycosidases including blood group antigen-specific a-glycosidases. These properties characterize them as a functionally distinct subpopulation of normal human enteric microflora comprised of An abstract of portions of this work was published in Gastroenterology 1983; 84:1191.

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“…An additional destructive effect by secreted carbohydrases was not demonstrated. However, in vivo these carbohydrases may render the glycocalyceal enzymes more vulnerable to digestive enzymes by removal of the polysaccharide or by digestion of the mucus covering the cell surface (23). The evidence that the damage of selected disaccharidases in vitro was solely due to the protease in the bacterial cell-free supernate or luminal fluid is supported by the fact that certain protease inhibitors could completely prevent any effect of the protease.…”

Section: ±2mentioning

confidence: 99%

“…These authors concluded that proteases produced by bacteria may play a role in the etiology of disaccharidase deficiency in bacterial overgrowth. Prizont (23) has recently described findings that suggest that sugars of small intestinal mucins are degraded by enzymes present in blind loop contents of rats. Therefore, some evidence exists in rats that products of bacterial growth modify macromolecules at the intestinal cell surface.…”

Section: Introductionmentioning

confidence: 99%

Effect of Secreted Bacteroides Proteases on Human Intestinal Brush Border Hydrolases

Riepe¹,

Goldstein²,

Alpers³

1980

J. Clin. Invest.

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A B S T R A C T Selected bacteroides species secreted various amounts of protease and glycosidase into their growth medium. Bacteroides vulgatus, distasonis, and ovatus secreted the most (31-60% of total). The secreted protease was similar in action to the protease within the organism, in that it had a broad pH optimum of 6-9, a Km app. for casein of 0.1 ,uM, and was inhibited by benzamidine, phenylmethylsulfonyl fluoride, diisopropylfluorophosphate (DIFP), and by an elastase inhibitor, Ac(Ala)3AlaCH2Cl.Exposure of human brush border preparations to the secreted protease reduced maltase and sucrase activities; the reduction could be prevented by DIFP. In contrast, brush border alkaline phosphatase activity either did not change or increased after exposure to bacterial secretions. >90% inhibition of secreted glycosidase using EDTA and p-chloromercuribenzoic acid did not prevent the reduction of brush border maltase and sucrase activity, suggesting that glucosidases were not likely to be involved in the destruction of brush border enzymes. Moreover, the bacterial proteases caused only a small net release of active maltase or sucrase from the brush border. Most of the loss of activity was due to destruction of the enzyme. Proximal bowel fluid of three patients with overgrowth contained DIFP-inhibitable protease that destroyed sucrase in isolated brush borders. A Bacteroides species was isolated from each sample that secreted protease and destroyed brush border sucrase. We conclude that in bacterial overgrowth syndromes, brush border damage may occur from protease(s) secreted by Bacteroides.

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Glycoprotein Degradation in the Blind Loop Syndrome

Cited by 20 publications

References 23 publications

Degradation of intestinal glycoproteins by pathogenic Shigella flexneri

Degradation of intestinal glycoproteins by pathogenic Shigella flexneri

Mucin degradation in human colon ecosystems. Isolation and properties of fecal strains that degrade ABH blood group antigens and oligosaccharides from mucin glycoproteins.

Effect of Secreted Bacteroides Proteases on Human Intestinal Brush Border Hydrolases

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