A novel bioactive peptide from the skin secretion of the dark-spotted frog, Pelophylax nigromaculatus

Amongst, antimicrobial peptides (AMPs) represent a promising group since they have unique bactericidal mechanisms comparing to their counterparts - antibiotics. Thus, it is hard for multi-resistant bacteria to develop resistance towards AMPs. <br><br>In this thesis, a novel peptide named QUB-1984 belonging to the nigrocin-2 family was identified from the skin secretion of Pelophylax nigromaculatus.

Primarily, cDNA encoding the biosynthetic precursor was cloned successfully, followed by “molecular cloning” which was used to deduce the mature peptide sequence. Subsequently, a series of technologies (SPPS, HPLC and MALDI-TOF) were used to synthesise, purify and identify the targeted peptide respectively. Afterwards, QUB-1984 was subjected to several functional tests such as antimicrobial, anticancer and haemolytic assays. <br><br>The results revealed the mature peptide sequence as follows: GLLGKILGAGKKVL-CGVSGLC.