Purification and Properties of Laticeptin, an Antimicrobial Peptide from Skin Secretions of the South American Frog Leptodactylus laticeps

Norepinephrine-stimulated skin secretions from the Sante Fe frog Leptodactylus laticeps contained high concentrations of a peptide, termed laticeptin, with the primary structure Gly-Val-Val-Asp-Ile-Leu-Lys-Gly-Ala-Ala-Lys- Asp-Leu-Ala-Gly-His-Leu-Ala-Thr-Lys-Val-Met-Asn-Lys-Leu.NH2. Laticeptin inhibited the growth of selected Gramnegative bacteria but the lack of activity against Gram-positive bacteria and the very low hemolytic activity is probably a consequence of the weak amphipathicity of the peptide in its a-helical conformation.