2026-10-11T05:27:51Z https://api.figshare.com/v2/oai

oai:figshare.com:article/32641905 2026-10-01T16:19:50Z portal_1172 item_type_8 month_year_10_2026

Molecular cloning, synthesis and bioactivity study of a bioactive peptide from the skin secretion of the Burmeister's leaf frog, <i>Phyllomedusa burmeisteri</i> Chenyu Liao (18135052) PUREID: 658701105 Antimicrobial peptides anticancer peptides haemolysis HPLC mass spectrometry molecular cloning Antibiotic resistance is a growing global health threat, highlighting the urgent need for novel antimicrobial agents. This study investigated the antimicrobial, anticancer, and toxicity properties of a bioactive peptide, QUB-1962, a phylloseptin-family peptide derived from the skin secretion of Burmeister's leaf frog, (Phyllomedusa burmeisteri), with a focus on its potential therapeutic applications. The peptide was first identified via molecular cloning, then synthesised by solid-phase peptide synthesis, and subsequently purified and characterised by HPLC and mass spectrometry. Its bioactivity was assessed through antimicrobial assays, haemolysis tests, and cell viability/toxicity assays. QUB-1962 exhibited broad-spectrum antimicrobial activity, showing the strongest efficacy against Staphylococcus aureus with a MIC of 8 μM, while also inhibiting Escherichia coli and Candida albicans. In anticancer assays, the peptide significantly inhibited the proliferation of human lung cancer cells with an IC₅₀ of 26.98 μM; however, it demonstrated a comparable level of cytotoxicity against normal human lung cells, indicating a lack of selectivity. Additionally, it displayed minimal hemolytic activity against horse red blood cells even at high concentrations, with less than 10% hemolysis observed at 100 μM. These results indicate that QUB-1962 has a favourable therapeutic index and represents a promising lead compound for the development of antimicrobial and anticancer therapeutics. Further optimisation and in vivo validation are required to fully establish its therapeutic potential.<br><br><i>Thesis is embargoed until 31 December 2030.</i> 2026-10-01T16:19:50Z Text Thesis 10.17034/32641905.v1 https://figshare.com/articles/thesis/Molecular_cloning_synthesis_and_bioactivity_study_of_a_bioactive_peptide_from_the_skin_secretion_of_the_Burmeister_s_leaf_frog_i_Phyllomedusa_burmeisteri_i_/32641905 All Rights Reserved Open Access after 2030-12-31