title: Effects of a Proline Endopeptidase on the Detection and Quantitation of Gluten by Antibody-Based Methods during the Fermentation of a Model Sorghum Beer.
abstract: The effectiveness of a proline endopeptidase (PEP) in hydrolyzing gluten and its putative immunopathogenic sequences was examined using antibody-based methods and mass spectrometry (MS). Based on the results of the antibody-based methods, fermentation of wheat gluten containing sorghum beer resulted in a reduction in the detectable gluten concentration. The addition of PEP further reduced the gluten concentration. Only one sandwich ELISA was able to detect the apparent low levels of gluten present in the beers. A competitive ELISA using a pepsin-trypsin hydrolysate calibrant was unreliable because the peptide profiles of the beers were inconsistent with that of the hydrolysate calibrant. Analysis by MS indicated that PEP enhanced the loss of a fragment of an immunopathogenic 33-mer peptide in the beer. However, Western blot results indicated partial resistance of the high molecular weight (HMW) glutenins to the action of PEP, questioning the ability of PEP in digesting all immunopathogenic sequences present in gluten.
authors.affiliation: Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
authors.forename: Rakhi
authors.initials: R
authors.lastname: Panda
authors.affiliation: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Fiedler
authors.affiliation: Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
authors.forename: Chung Y
authors.initials: CY
authors.lastname: Cho
authors.affiliation: Joint Institute for Food Safety and Applied Nutrition (JIFSAN), University of Maryland , College Park, Maryland 20740, United States.
authors.forename: Raymond
authors.initials: R
authors.lastname: Cheng
authors.affiliation: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
authors.forename: Whitney L
authors.initials: WL
authors.lastname: Stutts
authors.affiliation: Division of Food Processing Science and Technology, Office of Food Safety, CFSAN, FDA , Bedford Park, Illinois 60501, United States.
authors.forename: Lauren S
authors.initials: LS
authors.lastname: Jackson
authors.affiliation: Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
authors.forename: Eric A E
authors.initials: EA
authors.lastname: Garber
mesh_terms: D000906:Antibodies / Q000032:analysis; D001515:Beer / Q000032:analysis* / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods*; D005285:Fermentation; D005506:Food Contamination / Q000032:analysis*; D005983:Glutens / Q000032:analysis* / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D000085822:Prolyl Oligopeptidases; D012697:Serine Endopeptidases / Q000032:analysis; D045868:Sorghum / Q000737:chemistry* / Q000382:microbiology; D014908:Triticum / Q000737:chemistry / Q000382:microbiology
chemical_list: D000906:Antibodies; D005983:Glutens; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases
keywords: beer; fermentation; gluten; proline endopeptidase