Identification, isolation and bioactivity assessment of a novel peptide from the skin of Heilongjiang Brown Frog (Rana amurensis)

The bioactive substance form skin secretions, various peptides or proteins, was considered as treasures in medical treatment. The mechanism of antimicrobial peptides (AMPs) on antimicrobial activities was different from antibiotics and AMPs exhibit considerable value against antibiotic resistance.<br>In this study, a novel peptide named QUB-2207 was identified through “shotgun” cloning of biosynthetic precursor-encoding cDNA from the skin secretion of the Heilongjiang Brown Frog, Rana amurensis.

The peptide was chemically-synthesised by solid phase peptide synthesis. Antimicrobial assays and haemolytic assays were operated to investigate its antimicrobial activity, anticancer activity and haemolytic activity.<br>Synthetic QUB-2207 possesses a potent antimicrobial activity against S. aureus and C. albicans but showed low efficiency against E. coli with the MIC of 8 μM,16 μM and 64 μM respectively. In addition, QUB-2207 exhibited low haemolytic rate at 64 μM, and it did not show significant anticancer activity.