QUB-2614: a bioactive peptide from the defensive skin secretion of Odorrana schmackeri

There is no doubt that the skin secretions of amphibians play an important role in their daily life as a method of chemical defence. In recent biomedical research studies, these secretions have been shown to contain biologically-active compounds, such as anti-microbial peptides (AMPs) and anticancer peptides (ACPs), which are used by biomedical researchers as a source of potential novel drug leads or pharmacological tools.<br><br>In this thesis, an AMP was identified in the skin secretion of Odorrana schmackeri through "shotgun" cloning of biosynthetic precursor-encoding cDNA.

Online BLAST sequence alignment analysis was used to identify the mature peptide domain, -FLPLFASLAANLLPKIICKIAKKC, and the peptide was named QUB-2614. It’s computed molecular mass was confirmed by MALDI-TOF mass spectrometry, then QUB-2614 was chemically synthesised by the method of solid phase peptide synthesis (SPPS) and purified by reverse phase-HPLC.<br><br>Functional studies showed that QUB-2614 displayed antimicrobial activity against the Gram-negative bacterium, Escherichia (E.) coli, the Gram-positive bacterium, Staphylococus (S.) aureus, and the yeast, Candida (C.) albicans.