Structural conformation and self-assembly process of p31-43 gliadin peptide in aqueous solution. Implications for celiac disease.

Autor: Herrera MG; Instituto de Química y Fisicoquímica Biológicas - IQUIFIB (UBA-CONICET), Buenos Aires, Argentina., Gómez Castro MF; Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, UNLP-CONICET), La Plata, Argentina., Prieto E; Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, UNLP-CONICET), La Plata, Argentina., Barrera E; Institut Pasteur de Montevideo, Uruguay., Dodero VI; Faculty of Chemistry, Bielefeld University, Germany., Pantano S; Institut Pasteur de Montevideo, Uruguay.; Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, China., Chirdo F; Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, UNLP-CONICET), La Plata, Argentina.
Jazyk: angličtina
Zdroj: The FEBS journal [FEBS J] 2020 May; Vol. 287 (10), pp. 2134-2149. Date of Electronic Publication: 2019 Nov 23.
DOI: 10.1111/febs.15109
Abstrakt: Celiac disease (CeD) is a highly prevalent chronic immune-mediated enteropathy developed in genetically predisposed individuals after ingestion of a group of wheat proteins (called gliadins and glutenins). The 13mer α-gliadin peptide, p31-43, induces proinflammatory responses, observed by in vitro assays and animal models, that may contribute to innate immune mechanisms of CeD pathogenesis. Since a cellular receptor for p31-43 has not been identified, this raises the question of whether this peptide could mediate different biological effects. In this work, we aimed to characterize the p31-43 secondary structure by different biophysical and in silico techniques. By dynamic light scattering and using an oligomer/fibril-sensitive fluorescent probe, we showed the presence of oligomers of this peptide in solution. Furthermore, atomic force microscopy analysis showed p31-43 oligomers with different height distribution. Also, peptide concentration had a very strong influence on peptide self-organization process. Oligomers gradually increased their size at lower concentration. Whereas, at higher ones, oligomers increased their complexity, forming branched structures. By CD, we observed that p31-43 self-organized in a polyproline II conformation in equilibrium with β-sheets-like structures, whose pH remained stable in the range of 3-8. In addition, these findings were supported by molecular dynamics simulation. The formation of p31-43 nanostructures with increased β-sheet structure may help to explain the molecular etiopathogenesis in the induction of proinflammatory effects and subsequent damage at the intestinal mucosa in CeD.
(© 2019 Federation of European Biochemical Societies.)
Databáze: MEDLINE
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