Cleavage of Peptides from Amphibian Skin Revealed by Combining Analysis of Gland Secretion and in Situ MALDI Imaging Mass Spectrometry
BRUNETTI, ANDRÉS E.; MARANI, MARIELA M.; SOLDI, RAFAEL A.; MENDONÇA, JACQUELINE NAKAU; FAIVOVICH, JULIÁN; CABRERA, GABRIELA M.; LOPES, NORBERTO P.
American Chemical Society
Año: 2018 vol. 3 p. 5426 - 5426
Peptides from skin secretions of amphibians areconsidered important components of their immune system and alsoplay a relevant role in their defense mechanism against predators. Herein,by using mass spectrometry (MS), we characterize the sequence of 13peptides from the gland secretion of the hylid tree frog, Boana punctata.Using in situ matrix-assisted laser desorption ionization imaging MS of atransverse section of the skin tissue, we show that some peptides arestored as longer molecules that are cleaved after being secreted, whereasothers do not undergo any modification. Sequence comparison withpeptides from other Boana species and analysis of the three-dimensional theoretical structure indicate that this cleavage dependson both the presence of a specific sequence motif and the secondary structure. The fact that peptides undergo a rapid cleavageupon secretion suggests that stored and secreted peptides may have distinct roles for anuran survival, including defense againstpathogens and predators.