title: Effect of simulated gastric and intestinal digestion on temporal stability and immunoreactivity of peanut, almond, and pine nut protein allergens.
abstract: Current models of digestibility utilize pepsin stability to assess the safety of allergenic versus nonallergenic food proteins. Dietary protein digestion in vivo, however, requires acid denaturation and protease cleavage by pepsin, trypsin, and/or chymotrypsin. The ability of this approach to identify food protein stability in the mammalian gut may be limited. We determined the temporal stability and immunoreactivity of almond, pine nut, and peanut allergenic proteins under simulated physiologic gastric and intestinal digestive conditions in vitro. Gel electrophoresis and immunoblot analyses were used to determine protein stability and immunoreactivity, respectively. Peanut, almond, and pine nut proteins were pepsin- and pancreatin-stable and immunoreactive for up to 1 h after initiation of digestion. Moreover, successive acid denaturation and pepsin and pancreatin cleavage were necessary to hydrolyze these allergenic proteins and reduce their IgG- and IgE-binding capacity, which suggests that digestibility models must be improved for more accurate safety assessment of food allergens.
authors.affiliation: United States Food and Drug Administration , Laurel, Maryland 20708, United States.
authors.forename: Ondulla T
authors.initials: OT
authors.lastname: Toomer
authors.forename: Andrew
authors.initials: A
authors.lastname: Do
authors.forename: Marion
authors.initials: M
authors.lastname: Pereira
authors.forename: Kristina
authors.initials: K
authors.lastname: Williams
mesh_terms: D000485:Allergens / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D052179:Antigens, Plant / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D010367:Arachis / Q000009:adverse effects / Q000737:chemistry; D004044:Dietary Proteins / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D004063:Digestion; D005753:Gastric Mucosa / Q000201:enzymology / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008954:Models, Biological; D021184:Nut Hypersensitivity / Q000276:immunology; D009754:Nuts / Q000009:adverse effects / Q000737:chemistry*; D010189:Pancreatic Juice / Q000201:enzymology / Q000378:metabolism; D010194:Pancreatin / Q000378:metabolism; D021183:Peanut Hypersensitivity / Q000276:immunology; D010434:Pepsin A / Q000378:metabolism; D028223:Pinus / Q000009:adverse effects / Q000737:chemistry; D010940:Plant Proteins / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D055550:Protein Stability; D027861:Prunus / Q000009:adverse effects / Q000737:chemistry; D012639:Seeds / Q000009:adverse effects / Q000737:chemistry; D034421:Sus scrofa; D015854:Up-Regulation
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D004044:Dietary Proteins; D010940:Plant Proteins; D010194:Pancreatin; D010434:Pepsin A