Identification, characterisation and design of bioactive peptides from Chinese frogs

In the next chapter, DMPC-1OA is a lO-mer derivative with a Cha at the C-terminus from a dermaseptin peptide. DMPC-1 OA was found to have broad-spectrum antimicrobial activity against isolates from cystic fibrosis patients but a considerable haemolytic effect. To further improve haemolysis and stability, DMPC-1OB was designed using D-amino acid residues.

Through antimicrobial assay, cytotoxicity assay and in vitro and in vivo stability assays, it was found that DMPC-1OB had strong and broad-spectrum antimicrobial activity, low cytotoxicity and high stability in vitro and in vivo. In the last chapter, a 22-mer amidated peptide, named QUB-2395 with an internal disulphide bridge from the skin secretion of Odorrana versabilis, was subjected to the study. Truncated derivatives derived from the loop, were designed to detect the specific location of its active core.

QUB-2395 was a class of myotropic peptide producing potent and dose-dependent contraction of the smooth muscle of rat urinary bladder. However, its derivatives were tested and had a weaker myotropic function. However, it was found that QUB-2395 and its derivatives also exhibited in vitro antioxidant activity anti-inflammatory capacity.