Identification and bioactivity evaluation of peptide QUB-1909 from the skin secretion of Sylvirana nigrovittata

Finally, the purified peptide was tested for antibacterial, anticancer and haemolytic activity. The peptide sequence was determined to be FFPLLFGALSSLLPKLFa, and was named QUB-1909. The peptide showed significant inhibition of Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) at 4 µM and 32 µM. In an anti-cancer cell assay, the peptide showed an inhibitory effect against cancer cells (NCI-H838 lung cancer cells) at a concentration of 100 μM. In the haemolysis assay, the peptide showed significant haemolytic effects at 4 μM.The above experimental results indicated that QUB-1909 has potential for subsequent clinical application because of its antibacterial and anticancer activity.

However, it possesses an excessive haemolytic effect, so subsequent modifications are needed to reduce this cytotoxicity.<br><br><i>Thesis embargoed until 31 December 2027</i>