title: Interaction of 'toxic' and 'immunogenic' A-gliadin peptides with a membrane-mimetic environment.
abstract: Celiac disease (CD) is characterized by abnormally high concentrations of certain peptides in the small bowel. These peptides can be grouped in 'toxic' and 'immunogenic' classes, which elicit an innate immune response and an HLA-mediated adaptive response, respectively. It is not clear on which molecular mechanisms responses to these different classes are based, but the 31-43 (P31-43) and the 56-68 (P56-68) A-gliadin fragments are usually adopted as sequence representatives of toxic and immunogenic peptides, respectively. Here we report fluorescence experiments aiming to mimic the interaction of these peptides with the cell membrane surface by using sodium dodecyl sulphate (SDS) as a membrane-mimetic medium. We show that P31-43 is able to bind SDS micelles in a way that resembles mixed micelle formation. On the other hand, no binding at all could be detected for P56-68. This different behaviour could be related to the paracellular or transcellular route through which gluten peptides may cross the intestinal epithelium, and open new insights into the pathogenetic mechanisms of CD.
authors.affiliation: Department of Biochemistry and Biophysics, Second University of Naples, Naples, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Vilasi
authors.forename: I
authors.initials: I
authors.lastname: Sirangelo
authors.forename: G
authors.initials: G
authors.lastname: Irace
authors.forename: I
authors.initials: I
authors.lastname: Caputo
authors.forename: M V
authors.initials: MV
authors.lastname: Barone
authors.forename: C
authors.initials: C
authors.lastname: Esposito
authors.forename: R
authors.initials: R
authors.lastname: Ragone
mesh_terms: D002446:Celiac Disease / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D004396:Coloring Agents / Q000737:chemistry; D003902:Detergents / Q000737:chemistry; D005903:Gliadin / Q000737:chemistry / Q000276:immunology / Q000633:toxicity; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism; D008823:Micelles; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology / Q000633:toxicity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D003902:Detergents; D008823:Micelles; D010446:Peptide Fragments; D012967:Sodium Dodecyl Sulfate; D005903:Gliadin