title: Post-secretory events alter the peptide content of the skin secretion of Hypsiboas raniceps.
abstract: A novel family of antimicrobial peptides, named raniseptins, has been characterized from the skin secretion of the anuran Hypsiboas raniceps. Nine cDNA molecules have been successfully cloned, sequenced, and their respective polypeptides were characterized by mass spectrometry and Edman degradation. The encoded precursors share structural similarities with the dermaseptin prepropeptides from the Phyllomedusinae subfamily and the mature 28-29 residue long peptides undergo further proteolytic cleavage in the crude secretion yielding consistent fragments of 14-15 residues. The biological assays performed demonstrated that the Rsp-1 peptide has antimicrobial activity against different bacterial strains without significant lytic effect against human erythrocytes, whereas the peptide fragments generated by endoproteolysis show limited antibiotic potency. MALDI imaging mass spectrometry in situ studies have demonstrated that the mature raniseptin peptides are in fact secreted as intact molecules within a defined glandular domain of the dorsal skin, challenging the physiological role of the observed raniseptin fragments, identified only as part of the crude secretion. In this sense, stored and secreted antimicrobial peptides may confer distinct protective roles to the frog.
authors.affiliation: EMBRAPA Recursos Genéticos e Biotecnologia, Parque Estação Biológica, 70700-900 Brasília, DF, Brazil.
authors.forename: Beatriz S
authors.initials: BS
authors.lastname: Magalhães
authors.forename: Jorge A T
authors.initials: JA
authors.lastname: Melo
authors.forename: José Roberto S A
authors.initials: JR
authors.lastname: Leite
authors.forename: Luciano P
authors.initials: LP
authors.lastname: Silva
authors.forename: Maura V
authors.initials: MV
authors.lastname: Prates
authors.forename: Felipe
authors.initials: F
authors.lastname: Vinecky
authors.forename: Eder A
authors.initials: EA
authors.lastname: Barbosa
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Verly
authors.forename: Angela
authors.initials: A
authors.lastname: Mehta
authors.forename: Jacques R
authors.initials: JR
authors.lastname: Nicoli
authors.forename: Marcelo P
authors.initials: MP
authors.lastname: Bemquerer
authors.forename: Alan C
authors.initials: AC
authors.lastname: Andrade
authors.forename: Carlos
authors.initials: C
authors.lastname: Bloch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001001:Anura / Q000276:immunology* / Q000382:microbiology; D001419:Bacteria / Q000187:drug effects; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D012867:Skin / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D023181:Antimicrobial Cationic Peptides; D018076:DNA, Complementary