Searching for new proteins of fungal origin with potential medical application

BAUDOU F.; SEBASTIÁN KRAVETZ; DE MARZI MAURICIO; DIAZ MARÍA EUGENIA; GONZALEZ LORENA

Mar del Plata

Congreso; SAIC, SAFE, SAB, SAP 2019. Participan AACYTAL y NANOMED-AR.; 2019

SAIC, SAFE, SAB y SAP

Currently, interest in obtaining fungal bioactive compounds with medical applications has beenrenewed due to their great diversity and unique bioactivity compared to other natural sources.Bioactive proteins constitute an important part of the functional components in fungi, as theycan have antioxidant, antitumor and immunomodulatory activity. In particular, the antioxidantactivity is of great interest since the uncontrolled production of free radicals has been relatedto several diseases, including different types of cancer. The aim of this work was to obtainextracellular proteins and enriched protein extracts from Pleurotus ostreatus fruiting bodiesand mycelium in order to evaluate their antioxidant potential. In order to achieve this goal, P.ostreatus mycelium was grown on potato dextrose agar for 7 days and a plug of culture wasinoculated on potato dextrose broth. After 10 days, mycelium was harvested and liquid mediawas collected. Mycelium and fruiting bodies obtained from the local market were lyophilizedand homogenized with Tris-Glycine buffer pH 8.4. The homogenates were centrifuged and thesupernatants and collected liquid media were treated with ice cold ethanol to precipitatesoluble proteins. The precipitates were resuspended in buffer. Protein concentration wasmeasured by Bradford method and a SDS-PAGE was performed. Antioxidant activity ofhomogenates and extracts was evaluated using 2,2-azino-bis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS). ABTS radicals were generated by the reaction of ABTS 7 mM andpotassium persulfate 2.45 mM overnight at room temperature in the dark. For the assay,homogenates and extracts were incubated with the radical ABTS for 30 min in the dark and theabsorbance was measured at 734 nm. The results showed that the homogenates have a greatantioxidant capacity, being higher in that obtained from fruiting bodies. As for protein-enriched extracts, although the antioxidant activity of those corresponding to extracellularproteins and mycelium was lower, the one obtained from fruiting bodies showed similar valuesto mycelium homogenate. Therefore, these results are promising to continue the search fornew proteins with application in medicine.