Josip Juraj Strossmayer University of Osijek. Department of Chemistry. Department of Analytical, Organic and Applied Chemistry.
Abstract
Celijakija je autoimuni poremećaj netolerancije glutena koji se javlja kod ljudi s nasljednom predispozicijom. Gluten je protein koji se nalazi u žitaricama kao što su pšenica, ječam, raž i zob. Celijakija se može pojaviti u bilo kojoj životnoj dobi, a jedini način liječenja je doživotna prehrana bez glutena. Peptidi glutena se sastoje od glijadina i glutenina te sadrže oko 30-40% glutaminskih ostataka što ih čini dobrim supstratom za tkivnu transglutaminazu (tTG). tTG je enzim ovisan o kalciju koji se prvenstveno nalazi u crijevima gdje katalizira posttranslacijsku modifikaciju proteina stvaranjem izopeptidnih veza. Gluten koji je unesen u probavni sustav teško se razgrađuje crijevnim enzimima pa takve neprobavljene frakcije glutena podliježu reakcijama deamidacije ili umreženog povezivanja koje katalizira tTG. Modificirani glijadin potom potiče upalne reakcije koje dovode do aktivacije urođenog i stečenog imunosnog odgovora. tTG predstavlja ciljni autoantigen u imunosnoj reakciji čime nastaju specifična protutijela.Celiac disease is autoimmune disorder characterized by gluten intolerance and occurring in genetically predisposed people. Gluten is a protein found in cereals such as wheat, barley, rye and oats. Celiac disease can develop at any age and the only way of treatment is a life-long nutrition without gluten. Gluten is composed of gliadin and glutenin and it contains about 30-40% of glutamine residues making it a good substrate for tissue transglutaminase (tTG). tTG is calcium dependent enzyme which catalyses posttranslational modification of proteins by forming isopeptide bonds. Gluten, introduced in digestive system, is partially resistant to degradation by gastrointestinal enzymes and such undigestive fractions of gluten are susceptible for the reaction of deamidation or cross-linking, catalysed by tTG. Modified gliadin induces inflammatory reactions leading to activation of the innate and adaptive immune response. tTG represents the target autoantigen in the immune response, resulting in specific antibodies
