Decreased faecal exoglycosidase activities identify a subset of patients with active Crohn's disease.
1. alpha 1-Proteinase inhibitor (alpha 1-antitrypsin) is excreted in a deglycosylated form (M(r) 38,000) in the faeces of healthy subjects and in patients with quiescent Crohn's disease. By contrast, in most patients with active Crohn's disease, alpha 1-proteinase inhibitor is excreted in a glycosylated form (M(r) 51,000). 2. Faecal extracts containing deglycosylated alpha 1-proteinase inhibitor are able to deglycosylate alpha 1-proteinase inhibitor by an exoglycosidic process. Conversely, we demonstrate that in faecal extracts from patients excreting glycosylated alpha 1-proteinase inhibitor, glycosidase activities, such as N-acetyl-beta-glucosaminidase (EC 3.2.1.30), alpha-mannosidase (EC 3.2.1.24) and particularly beta-galactosidase (EC 3.2.1.23), are strongly decreased. 3. Degradation of glycosidases by proteases could not explain the decreased glycosidase activity in these faecal extracts. 4. Our data suggest that a modification of the bacterial colonic flora (or of its metabolic activity) occurs in most patients with active Crohn's disease and could be responsible for an impaired colonic salvage of carbohydrates.
el Yamani
J
J
Laboratoire de Biochimie, Faculté de Pharmacie, Université de Lille, France.
Mizon
C
C
Capon
C
C
Colombel
J F
JF
Fournet
B
B
Cortot
A
A
Mizon
J
J
D000118:Acetylglucosaminidase / Q000032:analysis / Q000378:metabolism; D000328:Adult; D003424:Crohn Disease / Q000201:enzymology*; D005243:Feces / Q000201:enzymology*; D005260:Female; D006031:Glycosylation; D006801:Humans; D008297:Male; D008361:Mannosidases / Q000032:analysis / Q000378:metabolism; D013997:Time Factors; D000515:alpha 1-Antitrypsin / Q000032:analysis* / Q000378:metabolism; D001616:beta-Galactosidase / Q000032:analysis / Q000378:metabolism
D000515:alpha 1-Antitrypsin; D008361:Mannosidases; D001616:beta-Galactosidase; D000118:Acetylglucosaminidase