Identification of multiple antimicrobial peptides from the skin of fine-spined frog, Hylarana spinulosa (Ranidae)

In this study, peptidomics and genomics analyses were used to study antimicrobial peptides from the skin of Hylarana spinulosa. Twenty-nine different antimicrobial peptide precursors were characterized from the skin of H. spinulosa, which produce 23 mature antimicrobial peptides belonging to 12 different families. To confirm the actual presence and characteristics of these antimicrobial peptides in the skin tissue extractions from H. spinulosa, we used two distinct methods, one was peptide purification method that combined gel filtration chromatography and reversed-phase high performance liquid chromatography (RP-HPLC), and the other was peptidomics approach based on liquid chromatography in conjunction with tandem mass spectrometry (LC–MS/MS). In the peptidomics approach, incomplete tryptic digestion and gas-phase fractionation (GPF) analysis were used to increase peptidome coverage and reproducibility of peptide ion selection. Multiple species of microorganisms were chosen to test and analyze the antimicrobial activities and spectrum of these antimicrobial peptides.