A peptide, QUB-1420, from the defensive skin secretion of Heilongjiang Brown Frog Rana amurensis

Abstract

Frogs, living within terrestrial, arboreal or freshwater aquatic ecosystems, rarely die of microbial or fungal infections, because their special skin protects them from these diseases. Thus, based on the requirement for survival they need an efficient anti-microbial defence system. In ancient China, people had already realised that frog could be used to cure some diseases. Currently, a lot of components in the frog skin secretions have been identified, such as biogenic amines, steroids, alkaloids and peptides and protein, many of which were proved to have different bio-activities. Therefore, frog secretions are regarded as a rich source to continuously provide valuable leads for novel drug development. Here we report a peptide named QUB1420, from the skin secretion of the Heilongjiang Brown Frog, Rana amurensis. The mature peptide was isolated and identified using a kit with provided UPM primer and a degenerate primer that was designed to a segment of 5’-untranslated regions of cDNAs, which were previously cloned from the skin of a closely-related Asian Species, by performing rapid amplification of cDNA ends (RACE) method. After that, solid phase Fmoc-based chemistry method was used to synthesise the peptide for the following functional experiments. The reverse-phase HPLC was employed to purify the synthetic peptide products. After a range of bioassays assessment, the antimicrobial, anticancer, protease inhibitory, and myotropic bioactivities of QUB1420 were investigated, However, QUB1420 did not display any bioactivity in the functional assays, whilst it may still have a specific bio-target on some other tissues, cells or hosts.

Date of Award	30 Aug 2017
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Yuxin Wu (Supervisor), Mei Zhou (Supervisor), Lei Wang (Supervisor) & Tianbao Chen (Supervisor)