Insights into Gliadin protein structure and oligomerization behavior

M. GEORGINA HERRERA; DIEGO SEBASTIAN VAZQUEZ; YVONNE HERTLE; RAMSIA SREIJ; THOMAS HELLWEG; VERONICA I. DODERO

Centro Cultural de la Ciencia (C3), CABA

Simposio; Fronteras en Biociencias 2; 2016

Instituto de Investigación en Biomedicina de Buenos Aires & Instituto Partner de la Sociedad Max Planck

Gliadin is a complex protein mixture present in wheat, rye and barley. This protein is not fully degraded by humans. It is known that gliadin and some of its proteolytic resistant peptides are responsible for immunological diseases, like celiac disease and gluten sensitivity which are complex immunological disorders with a prevalence of 1% and 7% among the healthypopulation, respectively. Despite intensive studies, the primary mechanism y which gliadin and its proteolytical resistant fragments cause immunological imbalance and disease still remains to be elucidated [2]. Recently, we showed that gliadin oligomerizes in water at physiological pH [3]. The occurrence of gliadin colloidal nanostructures can explain the up to now unexpected proteolytical resistance, and thus the hypothesis of incapability of digestive enzymes to access to the degradation sites of gliadin is reasonable. Here, we present dynamic light scattering and SAXS experiments that confirms the presence of gliadin oligomers in solution in an acidic medium mimetic to the stomach conditions. Also, we measured the morphology by Cryo-TEM and we provide computational evidence that validate the oligomerization observed experimentally.