Discovery and design of novel bioactive peptides from amphibian skin secretion

In addition, the peptides were purified and identified by high-performance liquid chromatography (HPLC) and MALDI-TOF MS, and their biological activity was determined.<br><br>In the third chapter, a natural active peptide, QUB-1369, was identified and isolated from Amolops hainanensis, and it was found to be more effective against the Gram-positive bacterium, S. aureus, and less effective against the Gram-negative bacterium, E.coli and yeast, in a series of functional assays.

This peptide was structurally-modified and it was found that the antimicrobial spectrum of the analogue, QUB-1464, was expanded to a certain extent, and the antimicrobial function was significantly improved. In addition, there was an inevitable decrease in haemolytic activity. Therefore, the rational design modification of this AMP helped to improve its therapeutic activity.<br><br>In Chapter 4, an antimicrobial peptide was identified in Agalychnis callidryas with a known sequence, and because it contained a specific sequence, it was necessary to investigate the relationship between its structure and function.