In this study, to clarify the bioactive polypeptides included in the skins and secretions of Bufo
, we screened the Japanese toad ( Bufo japonicus formosus
) skin cDNA library by colony polymerase chain reaction (PCR), and obtained a transcript of 1 075 bp consisting of 1 37 bp 5' untranslated region (UTR), 515 bp 3' UTR and a 423 bp open reading frame (ORF) encoding a polypeptide of 140 amino acid residues (GenBank accession number: KF359945). Homolog analysis showed a 70%-96% homology with sterol carrier protein-2 (SCP-2) present in other animals, which is implicated in lipid metabolism of other organisms. The gene SCP-2
of Chinese toad ( B. gargarizans
) was cloned from a first strand cDNA of Bufo
skin (GenBank accession number: KF381341) via PCR, whose encoding polypeptide has only one amino acid difference from that of Japanese toad. Tissue distribution analysis showed that SCP-2
expressed in all organs tested, though in the liver and spleen it manifested lower expression than in other organs. These findings might indicate SCP-2 being one of the active ingredients in toad skin. These findings may in turn have implications for further drug development from traditional Chinese medicine sources.