Characterized analysis of peptide QUB-1433 from the skin secretion of the dark-spotted frog (Pelophylax nigromaculatus)

Since the antibiotic resistance has become a severe difficulty in modern therapeutic treatment, many of them have been developed into clinical application for the treatment of microbial infection and cancer.<br><br>In this thesis, a potent natural antimicrobial peptide QUB-1433 was identified and cloned from the skin secretion of Pelophylax nigromaculatus via “shotgun” cloning.

According to the amino acid residues of QUB-1433, the pure peptide was synthesised and purified via solid-phase peptide synthesis and RP-HPLC. Subsequently, antimicrobial, anticancer and haemolysis assays were performed on QUB-1433 for its functional evaluation. From the results of a series of bioactive assays, QUB-1433 displayed activities of against Gram-positive bacteria and fungi (MIC values are 16 and 32 µM), but is lack in broad-spectrum of anticancer ability (MIC value is 128 µM).