Ocellatin-V1

Peptidomic analysis of norepinephrine-stimulated skin secretions from the Caribbean frog Leptodactylus validus Garman, 1888 led to the identification of three peptides with previously undescribed sequences that were structurally similar to those of antimicrobial peptides isolated from other species of leptodactylid frogs. These paralogs have been termed ocellatin-V1 (GVVDILKGAGKDLLAHALSKLSEKV.NH(2)), ocellatin-V2 (GVLDILKGAGKDLLAHALSKISEKV.NH(2)), and ocellatin-V3 (GVLDILTGAGKDLLAHALSKLSEKV.NH(2)). The very low antimicrobial potency (MIC>200microM) against Escherichia coli and Staphylococcus aureus associated with the peptides is probably a consequence of their lack of amphipathicity and reduced cationicity compared with active members of the ocellatin family from related species.

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.