Abstract
AbstractIncrease of infections caused by microorganisms resistant to conventional antibiotics is a health problem in Brazil and worldwide. The search for new molecules capable of inhibiting the growth of pathogens is a challenge for researchers, who find in venoms a rich source of biomolecules, including antimicrobial peptides (AMPs). The Brazilian scorpion,Tityus serrulatus, is one of the species that cause serious accidents, its venom is rich in neurotoxins that have been well characterized, highlighting their activities on channels (especially sodium and potassium). So, this work aimed to identify and characterize AMPs inT. serrulatusvenom. After milking and purification steps, the venom fractions were analyzed by liquid growth inhibition assay, the minimum inhibitory concentration (MIC) for different microorganisms was also tested. The fraction with antimicrobial activity was analyzed by electrophoresis and mass spectrometry, this AMP (molecular mass 6.881 kDa) has a similar amino acid sequences to TsTX-κ beta, a neurotoxin that acts on ion channels. The fragments from TsTX-κ beta were obtained, separated by high-performance liquid chromatography and subjected to biological tests. At high concentrations, these fragments showed hemolytic activity against human erythrocytes. Taken together, these data suggest that antimicrobial and hemolytic activities are associated by different sites from TsTX-κ beta, in addition to the identification of antimicrobial activity in a neurotoxin already known.Key ContributionMultifunction: antimicrobial and hemolytic activity associated to TsTX-κ beta, a neurotoxin that acts on potassium channels.
Publisher
Cold Spring Harbor Laboratory