Saccharomyces boulardii produces in rat small intestine a novel protein phosphatase that inhibits Escherichia coli endotoxin by dephosphorylation

Pediatr Res. 2006 Jul;60(1):24-9. doi: 10.1203/01.pdr.0000220322.31940.29. Epub 2006 May 11.

Abstract

Using a polyclonal antibody raised against a highly conserved sequence of 38 amino acids containing the activation site (VTDSAAGAT) common to mammalian and yeast alkaline phosphatases (AP), we identified in decapsidated Saccharomyces boulardii a protein phosphatase detected by autoradiography as a single signal (63 kD). Using an affinity chromatography column, the protein phosphatase could be concentrated 39.1-fold and presented as a doublet of two subunits. Compared with rat and bovine purified intestinal AP, the enzyme from S. boulardii had a greater ability to dephosphorylate the lipopolysaccharide (LPS) of Escherichia coli 055B5. When tested in vivo, intraperitoneal injection of intact LPS to rats produced, after 9 h, 100 ng/mL of circulating tumor necrosis factor-alpha with inflammatory lesions and apoptotic bodies in the liver and the heart, whereas rats injected with partially dephosphorylated LPS produced only 40 ng/mL tumor necrosis factor-alpha without organic lesions. In conclusion, S. boulardii is able to inhibit toxicity of E. coli surface endotoxins by the release of a protein phosphatase exhibiting a great capacity of dephosphorylation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / analysis
  • Alkaline Phosphatase / chemistry
  • Alkaline Phosphatase / metabolism
  • Alkaline Phosphatase / pharmacology
  • Amino Acid Sequence
  • Animals
  • Cattle
  • Endotoxins / antagonists & inhibitors*
  • Endotoxins / metabolism*
  • Female
  • Intestine, Small / enzymology*
  • Intestine, Small / microbiology*
  • Male
  • Molecular Sequence Data
  • Phosphoprotein Phosphatases / analysis
  • Phosphoprotein Phosphatases / chemistry
  • Phosphoprotein Phosphatases / metabolism*
  • Phosphoprotein Phosphatases / pharmacology
  • Phosphorylation / drug effects
  • Rats
  • Rats, Wistar
  • Saccharomyces / enzymology*
  • Tumor Necrosis Factor-alpha / analysis

Substances

  • Endotoxins
  • Tumor Necrosis Factor-alpha
  • endotoxin, Escherichia coli
  • Alkaline Phosphatase
  • Phosphoprotein Phosphatases