title: Purification, characterization and homology analysis of ocellatin 4, a cytolytic peptide from the skin secretion of the frog Leptodactylus ocellatus.
abstract: Neobatrachia is the amphibian suborder with the largest number of species and a most important source of bioactive peptides from frog skin secretions. However, 90% of the studies on this subject have been focused on the frog families Hylidae and Ranidae, while very little is known about peptides of other families, like Leptodactylidae. Our work reports for the first time the isolation and characterization of ocellatin 4 (GLLDFVTGVGKDIFAQLIKQI-NH(2)), a cytolytic peptide from the skin secretion of the South American frog Leptodactylus ocellatus. While most cytolytic amphibian skin peptides are selective for microorganisms and harmless for mammalian cells, the HC(50) of ocellatin 4 against human erythrocytes is 14.3muM. The interaction between ocellatin 4 and zwitterionic phospholipids in mammalian plasma membranes may be favored by its neutral charge at pH 7.0. Ocellatin 4 also shows some antibacterial activity (MICs(E. coli)(and)(S. aureus)=64muM) and its sequence shares similarities with the only six leptodactylid peptides previously known and with four peptides from Australian hylid frogs of the genus Litoria.
authors: Brazilian Center for Protein Research, Department of Cell Biology, University of Brasilia, Brasilia DF 70910-900, Brazil.
authors: Anna
authors: A
authors: Nascimento
authors: Alex
authors: A
authors: Chapeaurouge
authors: Jonas
authors: J
authors: Perales
authors: Antonio
authors: A
authors: Sebben
authors: Marcelo V
authors: MV
authors: Sousa
authors: Wagner
authors: W
authors: Fontes
authors: Mariana S
authors: MS
authors: Castro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification*; D001001:Anura; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D012867:Skin / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; C527482:ocellatin 4 protein, Leptodactylus ocellatus