title: Purification and characterization of antimicrobial and vasorelaxant peptides from skin extracts and skin secretions of the North American pig frog Rana grylio.
abstract: Eight peptides with differential growth-inhibitory activity against the gram-positive bacterium Staphylococcus aureus, the gram-negative bacterium Escherichia coli and the yeast, Candida albicans were isolated from an extract of the skin of the North American pig frog Rana grylio. The primary structures of these antimicrobial peptides were different from previously characterized antimicrobial peptides from Ranid frogs but on the basis of sequence similarities, the peptides may be classified as belonged to four previously characterized peptide families: the ranatuerin-1, ranatuerin-2 and ranalexin families, first identified in the North American bullfrog, Rana catesbeiana, and the temporin family first identified in the European common frog Rana temporaria. Peptides belonging to the brevinin-1, brevinin-2, esculentin-1, and esculentin-2 families, previously isolated from the skins of other species of Ranid frogs, were not identified in the extracts. The ranatuerin-1 and ranalexin peptides showed broadest spectrum of antimicrobial activity whereas the temporins were active only against S. aureus. Synthetic replicates of temporin-1Gb (SILPTIVSFLSKFL.NH(2)) and temporin-1Gd (FILPLIASFLSKFL.NH(2)) produced concentration-dependent relaxation of preconstricted vascular rings from the rat thoracic aorta (EC(50) = 2.4+/-0.1 microM for temporin-1Gb and 2.3+/-0.2 microM for temporin-1Gd). The antimicrobial peptides that were isolated in extracts of the skin R. grylio were present in the same molecular forms in electrically-stimulated skin secretions of the animal demonstrating that the peptides are stored in the granular glands of the skin in their fully processed forms.
authors.affiliation: Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University Medical School, Omaha, NE 68178, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Halverson
authors.forename: Y J
authors.initials: YJ
authors.lastname: Basir
authors.forename: J
authors.initials: J
authors.lastname: Dulka
authors.forename: F C
authors.initials: FC
authors.lastname: Knoop
authors.forename: P W
authors.initials: PW
authors.lastname: Abel
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D006461:Hemolysis; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009656:North America; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011898:Ranidae / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000737:chemistry* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000187:drug effects*; D014020:Tissue Extracts / Q000737:chemistry; D014665:Vasodilator Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D010455:Peptides; D014020:Tissue Extracts; D014665:Vasodilator Agents