Antimicrobial peptide protonectin disturbs the membrane integrity and induces ROS production in yeast cells

Abstract

Candidiasis is often observed in immunocompromised patients and is the 4th most common cause of bloodstream infections. However, antifungals are limited, so novel antifungal agents are urgently needed. Antimicrobial peptides (AMPs) are considered as potential alternatives of conventional antibiotics. In the present study, antimicrobial peptide protonectin was chemically synthesized and its antifungal activity and mode of action were studied. Our results showed that protonectin has potent antifungal activity and fungicidal activity against the tested fungi cells. Its action mode involved the disruption of the membrane integrity and the inducing of the production of cellular ROS. Furthermore, protonectin could inhibit the formation of biofilm and kill the adherent fungi cells. In conclusion, with the increase of fungal infection, protonectin may offer a new strategy and be considered as a potential therapeutic agent against fungal disease.

Antimicrobial activity and stability of the d-amino acid substituted derivatives of antimicrobial peptide polybia-MPI

“…Strains was grown overnight with shaking to mid-logarithmic phases described above (Wang et al 2015). The cultures containing 10 4 –10 5 CFU/ml was incubated with different concentration of peptides which determined by MIC assay via the broth microdilution method.…”

Application and bioactive properties of CaTI, a trypsin inhibitor from Capsicum annuum seeds: membrane permeabilization, oxidative stress and intracellular target in phytopathogenic fungi cells

“…Mitochondria are the primary site of oxidative metabolism of the cell, and their involvement in the production and degradation of ROS has been largely reported . These molecules are generated by oxygen reduction processes such as those during the electron transport chain . An increase in ROS production in all tested fungi exposed to the CaTI inhibitor was observed (Fig.…”

A Chitin-binding Protein Purified from Moringa oleifera Seeds Presents Anticandidal Activity by Increasing Cell Membrane Permeability and Reactive Oxygen Species Production

“…This is an important finding since C. krusei is a potentially multi-drug resistant pathogenic yeast due to its intrinsic resistance to fluconazole and tendency to develop reduced echinocandin susceptibility during prolonged therapy and under selection pressure (Scorzoni et al, 2013; Tavernier et al, 2015). The antifungal mode of action of Mo -CBP 2 is probably linked to its ability to disrupt the cell membrane integrity of C. albicans , as propidium iodide, which is membrane impermeable, was taken up by cells exposed to Mo -CBP 2 , and interacted with nucleic acids as revealed by the appearance of red fluorescence (Wang et al, 2015). Increasing permeability of cell membrane can result from depolarization, disruption of lipid domain organization, pore formation, and unbalance of intracellular electrochemical gradients, leading to loss of membrane functions and cell death (Lee and Lee, 2015; Lee et al, 2015).…”

“…Alternatively, Mo -CBP 2 could form transient pores through which it could gain access to the cell interior and enters into contact with intracellular targets (Li et al, 2012; Taniguchi et al, 2013; Choi and Lee, 2014). Regardless whether Mo -CBP 2 gained access or not to the Candida cell interior it promoted ROS generation, which are toxic to microorganisms (Mello et al, 2011; Wang et al, 2015). Like for other various antifungal proteins the mechanism of ROS generation after Mo -CBP 2 treatment of Candida cells is yet unknown.…”

“…Like for other various antifungal proteins the mechanism of ROS generation after Mo -CBP 2 treatment of Candida cells is yet unknown. Nevertheless, ROS are natural compounds produced during the cell metabolism and play important roles in cell signaling and homeostasis, and high levels of ROS generated under environmental stress can result in significant damage to cell structures (Wang et al, 2015). Additionally, excessive ROS damages proteins, lipids, and DNA (Deavall et al, 2012) that besides increasing cell membrane permeability can lead ultimately to cell death.…”