Identification and functional study of a novel bioactive peptide QUB-1761 from the venom of the Brazilian yellow scorpion, Tityus serrulatus

In this thesis, QUB-1761, a non-disulphide bridged peptide (NDBP), was discovered in the venom of the Brazilian yellow scorpion, Tityus serrulatus (T. serrulatus). The peptide was identified through molecular cloning by using a sense primer.

The synthetic peptide was obtained by solid phase peptide synthesis (SPPS), followed by purification and confirmation through reversed-phase high performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS). In broth microdilution assays, QUB-1761 had strong inhibitory effects on both Gram-positive and Gram-negative bacteria (MIC=8 µM for Staphylococcus aureus, MIC=32 µM for Escherichia coli).