Combination enzyme therapy for gastric digestion of dietary gluten in patients with celiac sprue.
OBJECTIVE
Celiac sprue is a multifactorial disease characterized by an inflammatory response to ingested gluten in the small intestine. Proteolytically resistant, proline- and glutamine-rich gluten peptides from wheat, rye, and barley persist in the intestinal lumen and elicit an immune response in genetically susceptible persons. We investigated a new combination enzyme product, consisting of a glutamine-specific endoprotease (EP-B2 from barley) and a prolyl endopeptidase (SC PEP from Sphingomonas capsulata), for its ability to digest gluten under gastric conditions.


METHODS
The ability of this combination enzyme to digest and detoxify whole-wheat bread gluten was investigated. In vitro and in vivo (rat) experimental systems were developed to simulate human gastric digestion, and the resulting material was analyzed by high-performance liquid chromatography, enzyme-linked immunoabsorbent assay, and patient-derived T-cell proliferation assays.


RESULTS
The analysis revealed that EP-B2 extensively proteolyzes complex gluten proteins in bread, whereas SC PEP rapidly detoxifies the residual oligopeptide products of EP-B2 digestion. In vitro dose variation data suggests that an approximate 1:1 weight ratio of the 2 enzymes should maximize their synergistic potential. The efficacy of this 2-enzyme glutenase was verified in a rat model of gastric gluten digestion.


CONCLUSIONS
By combining 2 enzymes with gastric activity and complementary substrate specificity, it should be possible to increase the safe threshold of ingested gluten, thereby ameliorating the burden of a highly restricted diet for patients with celiac sprue.
Gass
Jonathan
J
Department of Chemical Engineering, Stanford University, Stanford, California, USA.
Bethune
Michael T
MT
Siegel
Matthew
M
Spencer
Andrew
A
Khosla
Chaitan
C
D000818:Animals; D002446:Celiac Disease / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004063:Digestion / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004357:Drug Synergism; D005765:Gastrointestinal Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D005973:Glutamine / Q000378:metabolism; D005983:Glutens / Q000276:immunology / Q000378:metabolism*; D001467:Hordeum / Q000201:enzymology*; D006801:Humans; D000085822:Prolyl Oligopeptidases; D051381:Rats; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D020578:Sphingomonas / Q000201:enzymology*; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D004338:Drug Combinations; D005765:Gastrointestinal Agents; D005973:Glutamine; D005983:Glutens; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases