A family of acyclic brevinin-1 peptides from the skin of the Ryukyu brown frog Rana okinavana.
The 24 amino-acid residue antimicrobial peptide, brevinin-1 is synthesized in the skins of a wide range of species of Eurasian and North American frogs belonging to the genus Rana. All previously characterized brevinin-1 peptides contain the cyclic heptapeptide domain Cys18-(Xaa)4-Lys-Cys24 at the COOH-terminus of the molecule. Four structurally related peptides were isolated from an extract of the skin of the Ryukyu brown frog Rana okinavana. The amino acid sequences of the peptides [Phe-(Xaa)4-Ile-(Xaa)2-Leu-Ala-Lys-Gly-Leu-Pro-Ser-Leu-Ile-Xaa-Leu-Xaa-Lys-Lys.NH2] identified them as members of the brevinin-1 family that lacked the COOH-terminal cyclic domain but contained a C-terminally alpha-amidated residue. It is suggested, as one possibility, that the Cys18 in the brevinin-1 consensus sequence has been deleted and the Cys24 residue has mutated to a glycine that acts as substrate for peptidyl-glycine alpha-amidating monooxygenase. The peptides potently inhibited the growth of Escherichia coli and Staphylococcus aureus confirming that a cyclic domain is not necessary for antimicrobial activity. A fifth peptide (SFLNFFKGAA10KNLLAAGLDK20LKCKISGTQC30), that also displayed broad-spectrum antimicrobial activity, was isolated from the skin extract and showed structural similarity with members of the ranatuerin-2 family previously isolated from the skin of North American ranid frogs.
Conlon
J Michael
JM
Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates. jmconlon@uaeu.ac.ae
Sonnevend
Agnes
A
Jouenne
Thierry
T
Coquet
Laurent
L
Cosquer
David
D
Vaudry
Hubert
H
Iwamuro
Shawichi
S
D000595:Amino Acid Sequence; D029845:Amphibian Proteins; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D003545:Cysteine / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D005260:Female; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D011506:Proteins / Q000737:chemistry; D011898:Ranidae; D012867:Skin / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects; D014020:Tissue Extracts / Q000737:chemistry / Q000302:isolation & purification
D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D011506:Proteins; D014020:Tissue Extracts; C121230:ranatuerin; D003545:Cysteine