Abstract
In recent years, the antibiotic resistance of bacteria has stimulated the development of new antibiotics. Antimicrobial peptides (AMPs) from amphibian skin secretions possess broad-spectrum antimicrobial activities through the mechanism that is unlikely to induce antibiotic resistance. Thus, AMPs are great candidates for new antibiotics.In this study, the precursor-encoding cDNA sequence of QUB-2652 was identified in the skin secretion of Phyllomedusa palliata by ‘Shotgun’ cloning. Then, QUB-2652 was synthesised by solid phase peptide synthesis (SPPS) according to its translated putative mature peptide sequence. After authenticated by Matrix-assisted laser desorption/ionisation Time-of-flight mass spectrometry and purified by Reversed-phase high performance liquid chromatography, the pure QUB-2652 was finally subjected to some functional tests.
According to the BLAST analysis, QUB-2652 showed high sequence similarity with dermaseptins. Results of functional tests showed that QUB-2652 possessed prominent antimicrobial activities against E. coli, S. aureus and C. albicans with the minimum inhibitory concentrations of 2, 2 and 1 µM, respectively. QUB-2652 also showed strong anti-proliferative effects on NCI-H157, PC-3 and U251MG cell lines. Meanwhile, the haemolytic activity of QUB-2652 on horse erythrocytes was 3.6% at 1 µM and 10.6% at 2 µM.
This study is expected to inspire further studies on peptides from frog skin secretions and provide useful clues for developing new peptide antibiotics and anticancer drugs.
| Date of Award | Jul 2018 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Lei Wang (Supervisor), Lei Li (Supervisor), Tianbao Chen (Supervisor) & Christopher Shaw (Supervisor) |