An antimicrobial peptide QUB-1925 from scorpion venom of Androctonus bicolor: molecular cloning of biosynthetic precursor-encoding cDNA and bioactivity study

This thesis focused on a novel antimicrobial peptide discovered from Androctonus bicolor. The QUB-1925 precursor-encoding cDNA was cloned by “shotgun” cloning of the venom-derived cDNA library, and the peptide was chemically synthesised by using the solid phase peptide synthesiser.

Reverse phase high performance liquid chromatography (RP-HPLC) and LCQ Fleet ion-trap mass spectrometer were employed to purify the crude synthesised peptide and confirm the identity of this peptide, respevtively. Finally, the purified peptide was used to perform antimicrobial assays, haemolysis assay, and anti-tumour cell assays. <br><br>QUB-1925 presented inhibition effect on gram-positive bacteria, S. aureus, and gram-negative bacterium, E. coli, but little effect against the fungi, C. albicans.