Laticeptin

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.NH(2). Laticeptin inhibited the growth of selected Gram-negative 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 alpha-helical conformation.

It is proposed that the current nomenclature by which individual antimicrobial peptides from the skins of frogs belonging to the genus Leptodactylus are named from the species of frog from which they were isolated should be replaced by one that emphasizes the fact that these peptides are evolutionarily related. As the ocellatins from Leptodactylus ocellatus were the first such peptides to be characterized, it is suggested that all orthologous peptides should be described as "ocellatins". Consistent with accepted terminology for other families of antimicrobial peptides, the upper case initial letter of the species is used to indicate their origin and isoforms are designated by numbers. When two species begin with the same initial letter, a second distinguishing letter shall be employed. Thus, the terms ocellatin-1, -2, -3, and -4 are retained for the parent peptides. Fallaxin is replaced by ocellatin-F1, pentadactylin by ocellatin-P1, laticeptin by ocellatin-L1, syphaxin by ocellatin-S1, and the paralogs from L. validus are termed ocellatin-V1, -V2, and -V3.