Peptidases intestinais de Danaus plexippus L. como uma nova perspectiva na produção de um leite hipoalergênico

• Autor(a) principal: Oliveira, João Pedro Brasil de
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/48081
• topic: Leite hipoalergênico; peptidases; Danaus plexippus

The main source of food allergy in childhood is the bovine milk and the lack of treatment may cause gastrointestinal, breathing and dermatological problems. Milk allergy is caused by its proteins, the caseins represent 80% of all proteins present in milk. The whey protein fraction (20%) is composed, mainly, by α lactalbimin and β-lactoglobulin. The aim of this study was to evaluate the potential of gut peptidases from Danaus plexuppus in the hydrolysis of milk proteins. Proteolytic assay was performed in different values of pH and the residual proteolytic activity of the extract was determined in different times of reaction. The ability to hydrolyze the milk proteins was determined by zimograma using different substrate and in vitro assay. It was performed ion exchange chromatography (CM and DEAE-Sepharose) and affinity chromatography (HiTrap-Benzamidine) to purify one of the proteins of the crude extract. The proteolytic activity of the gut extract was 2.6x higher in pH 9.0 compared to pH 6.5. The gut peptidases from D. plexippus stayed stable in the first hour of the reaction, but after 24 hours, the residual activity represented 44% of the original. The gut peptidases were able to hydrolyze the casein fraction (an extensive hydrolysis). The whey proteins fraction presented a significant hydrolysis degree only after pre incubation in denaturant temperatures. It was reported the lack of positive proteins, in the gut extract, in pH 7.2. Two serine peptidases were separated from the gut extract in the affinity chromatography and one of them was able to hydrolyze all the milk proteins tested in this study. The gut peptidases from D. plexuppus presented a potential in the production of hypoallergenic hydrolysates of the bovine milk once they are able to extensively hydrolysate the casein fraction and partially hydrolysates the whey protein fraction. Further tests, however, need to be performed to validate the potential of these peptidases.