Amphibian Skin Secretomics: Application of Parallel Quadrupole Time-of-Flight Mass Spectrometry and Peptide Precursor cDNA Cloning to Rapidly Characterize the Skin Secretory Peptidome ofPhyllomedusa hypochondrialisazurea:Discovery of a Novel Peptide Family, the Hyposins

This study reports the variety of peptides present in the skin secretory peptidome of Phyllomedusa hypochondrialis azurea. Peptide structures, along with post-translational modifications, were elucidated by QTOF MS/MS analysis, cDNA sequencing, or a combination of both. Twenty-two peptides, including 19 novel structures, were identified from six different structural classes, including tryptophyllins, dermorphins, and a novel group of peptides termed hyposins. The study demonstrates the power of this combined approach to mine the rich peptidome compliment of the amphibian defensive skin secretome.