title: Celiac-related properties of chemically and enzymatically modified gluten proteins.
abstract: The effects of chemical (acid-heating treatment) and enzymatic (microbial transglutaminase, TGase) modification (deamidation) of gluten proteins on their physicochemical and celiac disease-related properties were studied. Ammonia release, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and sample solubility analyses were employed to check the extent of gluten modification. Among different treatments achieved, the acid-heating treatment performed at 90 degrees C for 3 h induced gluten deamidation, paralleling an increase of gluten solubility without relevant proteolysis. Changes in the immunoreactivity of celiac IgA anti-gliadin antibodies (AGAs) to modified gluten proteins were detected by using a competitive indirect enzyme-linked immunosorbent assay method. Chemical deamidation by acid-heating treatment of gluten lowered IgA-AGA immunoreactivity. IgA-AGA immunoreactivity to gliadins was increased when they were submitted to TGase-catalyzed deamidation. The acid-heating treatment of gluten reduced its cytotoxic activity on human colon adenocarcinoma LoVo cell line. These results showed that chemical deamidation of gluten may be envisaged as a way to lower the potential risk for celiac people due to widespread use of gluten as a food additive.
authors.affiliation: Dipartimento di Scienze Molecolari Agroalimentari, Università di Milano, and Centre for the Prevention and Diagnosis of Celiac Disease, Fondazione IRCCS, Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan 20133, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Berti
authors.forename: Leda
authors.initials: L
authors.lastname: Roncoroni
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Falini
authors.forename: Rosita
authors.initials: R
authors.lastname: Caramanico
authors.forename: Ersilia
authors.initials: E
authors.lastname: Dolfini
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Bardella
authors.forename: Luca
authors.initials: L
authors.lastname: Elli
authors.forename: Claudia
authors.initials: C
authors.lastname: Terrani
authors.forename: Fabio
authors.initials: F
authors.lastname: Forlani
mesh_terms: D002446:Celiac Disease / Q000209:etiology*; D045744:Cell Line, Tumor; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003110:Colonic Neoplasms / Q000473:pathology; D005903:Gliadin / Q000276:immunology; D005983:Glutens / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007070:Immunoglobulin A / Q000276:immunology; D011503:Transglutaminases / Q000378:metabolism
chemical_list: D007070:Immunoglobulin A; D005983:Glutens; D005903:Gliadin; D011503:Transglutaminases