Host-defence peptides from frog skin secretions: identification and bioactivity evaluation and optimisation

A series of peptides were designed based on brevinin-1W peptide. Results indicated that proline and glycine could both influence the bioactivity of peptide while the proline exhibited stronger impact than the glycine residue and where the kink structure interrupted helical structure, was critical to balance the antimicrobial activity and haemolytic activity. To test the interactions between positive charges and hydrophobicity with bioactivity of peptide, five analogues were designed based on peptide PSN-PC.

The hydrophobicity played a more important role in haemolytic activity compared with positive charges. Therefore, the balance between hydrophobicity and positive charges is essential for peptides to balance the cytotoxicity and antimicrobial activity. <br><br><i>Thesis embargoed until 31 December 2026</i>.