Identification and activity assessment of a bioactive peptide, QUB-1938, from the skin secretion of the Broad-folded frog (Hylarana latouchii)

The detailed steps of which are as follows:1) Molecular cloning begins with the extraction of mRNA from skin secretions of target frog and the construction of its cDNA library. The full-length cDNA-encoded precursors were obtained through ‘shotgun’ cloning, and then amino acid sequences of peptide was predicted from the precursors. 2) After obtaining the sequence of the mature peptide, the solid-phase peptide synthesis (SPPS) was performed to synthesis the target peptide.

The synthesized crude peptide product was purified by Reverse phase high performance liquid chromatography (HPLC), and the purified collected product was further verified by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF MS). 3) A series of bioassays including antibacterial experiments, anticancer experiments, haemolysis experiments and trypsin inhibitor experiments, were carried out to evaluate bioactivity of the target peptide.