A bioactive peptide QUB2870 from the defensive skin secretion of the Heilongjiang brown frog (Rana amurensis)

Many of these peptides possess anticancer, antiviral, trypsin inhibitory and antimicrobial properties, and therefore their potential therapeutic value has been focused on by increasing numbers of researchers.<br><br>The main objectives of this study were to isolate, identify, chemically-synthesise and clone the precursor-encoding cDNA of a bioactive peptide from the skin secretion of the Heilongjiang brown frog (Rana amurensis).

A “shotgun” cloning technique was employed to select the precursor sequence and a cDNA library was established for amplification of the target DNA portion. The peptide was isolated and identified using molecular cloning, online BLAST analysis, and MALDI-TOF mass spectrometry.<br><br>The mature peptide, deduced from cDNA, was named QUB-2870, (SLLGLLKGAGKTLLSAGLNKIACKLTGKC-COOH), and consisted of 29 amino acid residues. It was synthesised by the method of solid phase peptide synthesis (SPPS) and further purified by rp-HPLC.