Host-defense peptides isolated from the skin secretions of the Northern red-legged frog Rana aurora aurora.
Antimicrobial peptides in the skin secretions of anurans constitute a component of the innate immunity that protects the organism against invading pathogens. Four peptides with antimicrobial activity were isolated in high yield from norepinephrine-stimulated skin secretions of the Northern red-legged frog Rana aurora aurora and their primary structures determined. Ranatuerin-2AUa (GILSSFKGVAKGVAKNLAGKLLDELKCKITGC) showed potent growth-inhibitory activity against a range of Gram-positive and Gram-negative bacteria (minimum inhibitory concentrations < 20 microM) but low hemolytic activity against human erythrocytes (50% hemolysis at 290 microM). Brevinin-1AUa (FLPILAGLAAKLVPKVFCSITKKC) and brevinin-1AUb (FLPILAGLAANILPKVFCSITKKC) also showed potent antimicrobial activity but were strongly hemolytic (HC50 < 10 microM). Temporin-1AUa (FLPIIGQLLSGLL.NH2) atypically lacked a basic amino acid residue and showed very weak antimicrobial and hemolytic activity. Its biological function remains to be established. The primary structures of the antimicrobial peptides are consistent with a close phylogenetic relationship between R. aurora, Rana boylii and Rana luteiventris.
Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al-Ain, United Arab Emirates. jmconlon@uaeu.ac.ae
J Michael
JM
Conlon
Agnes
A
Sonnevend
Carlos
C
Davidson
Anni
A
Demandt
Thierry
T
Jouenne
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D006461:Hemolysis; D006801:Humans; D007113:Immunity, Innate; D008297:Male; D008969:Molecular Sequence Data; D009638:Norepinephrine / Q000494:pharmacology; D011898:Ranidae / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D012867:Skin / Q000737:chemistry* / Q000378:metabolism
D023181:Antimicrobial Cationic Peptides; D009638:Norepinephrine