Antifungal action of Ts1, the major toxin from Tityus serrulatus venom
Eliane C. Arantes Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto - University of São Paulo, Ribeirão Preto-SP, Brazil
Abstract:
Cationic antimicrobial peptides and proteins are among the earliest molecular effectors of the innate arm of immunity in humans and other vertebrates. In this work, we evaluate the effects of Ts1, the major toxin from Tityus serrulatus venom (Tsv) on filamentous fungi growth. Ts1, a cationic peptide, was isolated from Tsv by ion-exchange chromatography. The growth inhibition of different filamentous fungi (Neurospora crassa, Penicillum ochrochloron, Penicillum verrucosum, Penicillum waksmanii, Penicillum corylophilum, Penicillum veridicatum, Aspergillus terreus, Aspergillus niger, Aspergillus phoenix, Aspergillus fumigatus, and Talaromyces flavus) was evaluated by quantitative microplate reader assay (Broekaert et al., 1990).Ts1 (6, 3, 1.5 and 0.7 ug/100 uL) showed dose-dependent antifungal activity, specially against A. nidulans, inhibiting 100% of fungal growth at a dose of 3 ug/100 uL. Ts1 has structural similarity to a defensin already known, the Drosomicin. The action of Ts1, like other cationic toxins, was intensified by increasing the concentration of Ca2+ from the medium. The antifungal effect of Ts1may be mediated by the interaction of the toxin with fungus membrane, destabilizing the membrane structures and altering its permeability.
Support: CNPq, FAPESP, CAPES.
