Saccharomyces boulardii enhances N-terminal peptide hydrolysis in suckling rat small intestine by endoluminal release of a zinc-binding metalloprotease.

Nature Publishing Group 2002

UCL - MD/GYPE - Département de gynécologie, d'obstétrique et de pédiatrie
UCL - MD/MINT - Département de médecine interne
UCL - (SLuc) Centre de pathologie anorectale de l'enfant
UCL - (SLuc) Centre de thérapie tissulaire et cellulaire
UCL - (SLuc) Service de pédiatrie générale
Buts, Jean-Paul
Dekeyser, Nadine
Stilmant, Catherine
Sokal, Etienne
Marandi, Soheila

Saccharomyces boulardii (S. boulardii), a biotherapeutic agent effective in acute and chronic enterocolopathies, produces trophic intestinal effects at least in part mediated by the endoluminal release of polyamines. However, the effects of the yeast on peptide hydrolysis have not yet been studied. The objectives of this study were to assess in suckling rats the endoluminal and mucosal aminopeptidase activities in response to S. boulardii treatment and to analyze their related mechanisms. Peptidase activities were assayed on yeast cells by using several L-amino acid-p-nitroanilide substrates in the pH range of 2 to 10. A marked hydrolytic activity was found for L-leucine-p-nitroanilide that peaked at pH = 8 (K(m) = 0.334 mM, V(max) = 44.7 micromol.min(-1).g(-1) protein). N-terminal peptide hydrolysis was confirmed using as substrate L-Leu-Gly-Gly (K(m) = 4.71 mM, V(max) = 18.08 micromol.min(-1).g(-1) protein). Enzyme reactions were inhibited in the presence of 1 mM Zn(2+). Oral treatment of sucklings with S. boulardii significantly enhanced jejunal and ileal mucosal leucine-aminopeptidase activities by 24 and 34%, respectively, over controls. In concordance, aminopeptidase activity was enhanced in jejunal and ileal endoluminal fluid samples by 47 and 105%, respectively. By use of an IgG-purified antibody raised against the zinc-binding domain common to metalloproteases, the yeast aminopeptidase was immunoprecipitated and detected as an heteromeric enzyme of 108 and 87-kD subunits. S. boulardii, when given orally to suckling rats, is able to significantly enhance hydrolysis of N-terminal oligopeptides in both endoluminal fluid and intestinal mucosa by the endoluminal release of a leucine aminopeptidase that appears to be a zinc-binding metalloprotease belonging to the M1 family of peptidases.

Amino Acid Sequence; Aminopeptidases; Animals; Animals, Newborn; Animals, Suckling; Fungal Proteins; Humans; Intestinal Mucosa; Molecular Sequence Data; Peptides; Rats; Rats, Wistar; Saccharomyces; Zinc; info:eu-repo/semantics/article

English

UCDLC oai:dial.uclouvain.be:boreal:9113
boreal:9113
info:doi/10.1203/00006450-200204000-00021
info:pmid/11919341
urn:ISSN:0031-3998
urn:EISSN:1530-0447
1130585740

UNIVERSITE CATHOLIQUE DE LOUVAIN
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