Abstract
Celiac Sprue is a multifactorial disease characterized by an intestinal inflammatory response to ingested gluten. Proteolytically resistant gluten peptides from wheat, rye, and barley persist in the intestinal lumen and elicit an immune response in genetically susceptible individuals. Here, we demonstrate the in vivo ability of a gluten-digesting protease (“glutenase”) to accelerate the breakdown of a gluten-rich solid meal. The proenzyme form of endoprotease B, isoform 2 from Hordeum vulgare (EP-B2), was orally administered to adult rats with a solid meal containing1gof gluten. Gluten digestion in the stomach and small intestine was monitored as a function of enzyme dose and time by high-performance liquid chromatography and mass spectrometry. In the absence of supplementary EP-B2, gluten was solubilized and proteolyzed to a limited extent in the stomach and was hydrolyzed and assimilated mostly in the small intestine. In contrast, EP-B2 was remarkably effective at digesting gluten in the rat stomach in a dose- and time-dependent fashion. At a 1:25 EP-B2/gluten dose, the gastric concentration of the highly immunogenic 33-mer gliadin peptide was reduced by more than 50-fold within 90 min with no overt signs of toxicity. Evaluation of EP-B2 as an adjunct to diet control is therefore warranted in celiac patients.
Footnotes
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This work was supported by a Stanford Graduate Fellowship and a National Science Foundation Fellowship (to H.V.). This work was also supported by a National Institutes of Health Cellular and Molecular Biology Training Grant (to M.T.B.). This work was supported in part by National Institutes of Health Grant R01 DK63158.
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A U.S. patent application (20050249719) based on this subject has been licensed to Alvine Pharmaceuticals, Inc., Palo Alto, CA. C.K. has stock ownership in the company.
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doi:10.1124/jpet.106.104315.
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ABBREVIATIONS: PEP, prolyl endopeptidase; EP-B2, endoprotease B, isoform 2 from Hordeum vulgare; HPLC, high-performance liquid chromatography; LC-MS/MS, liquid chromatography-assisted tandem mass spectrometry.
- Received March 13, 2006.
- Accepted June 2, 2006.
- The American Society for Pharmacology and Experimental Therapeutics
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