APDEF1, a defensin of Adenanthera pavonina seeds, induces hydrogen peroxide, membrane permeabilization and shows strong antimicrobial activity against the yeast model Saccharomyces cerevisiae

JÚLIA RIBEIRO SOARES; JULIA MIRANDA FARDIN; GÉSSIKA SILVA SOUZA; MARIANA REGENTE; LAURA DE LA CANAL; VALDIRENE MOREIRA GOMES; ANDRÉ DE OLIVEIRA CARVALHO

Cartagena

Congreso; XXII Congreso Latinoamericano de Microbiología y 4º Congreso Colombiano de Microbiología; 2014

Asociación Colombiana de Microbiología

Introduction Different types of antimicrobial peptides (AMPs) have been identified in seeds of different plant species, and they have a broad spectrum of inhibitory activity which includes gram-negative and positive bacteria, fungi and other parasites. The objective of this study was evaluate the antimicrobial activity of the defensin APDEF1 against the yeast model Saccharomyces cerevisiae. Materials and methods Peptides were extracted from the seeds and submitted to ammonium sulfate fractionation, dialyse against distilled water and then submitted to chromatographic methods. A peptide of 7 kDa was sequenced and tests were performed to evaluate its antimicrobial activity by determining the minimum inhibitory concentration (MIC), the capacity of permeated membranes analyzed through the uptake of dye sytox green and induction of the production of hydrogen peroxide by the cells after treatment with the defensin by marking wih diaminobenzidine (DAB) Results The primary structure of this peptide showed homology with defensins of plants and we named this peptide APDEF1. This defensin was able to inhibit the growth of S. cerevisiae, presenting MIC of 40 ug/ml and an antimicrobial activity fungicide, require a maximum of 18hs to cause the unfeasibility of cells. The test of permeabilization of membranes revealed that the APDEF1 was able to modify the plasma membrane of yeast. The treatment with the 2.5 ug/ml of the defensin induced the production of hydrogen peroxide after 18 h of assay. Conclusions These results show that the defensin APDEF1 presents a strong antimicrobial activity against cells of yeast cells killing them in 18 h. The cells after treatment present the membrane permeabilized with an increased in the production of hydrogen peroxide. These results show that there is a great potential to use it as a new drug for the treatment of fungal diseases, further studies are necessary for the understanding of its complete mechanism of action.