Antimicrobial peptides with therapeutic potential from skin secretions of the Marsabit clawed frog Xenopus borealis (Pipidae).
Nine peptides with differential growth inhibitory activity against Escherichia coli and Staphylococcus aureus were isolated from norepinephrine-stimulated skin secretions of the tetraploid frog Xenopus borealis Parker, 1936 (Pipidae). Structural characterization of the peptides demonstrated that they were orthologous to magainin-2 (1 peptide), peptide glycine-leucine-amide, PGLa (2 peptides), caerulein-precursor fragments, CPF (4 peptides), and xenopsin-precursor fragments, XPF (2 peptides), previously isolated from Xenopus laevis and X. amieti. In addition, a second magainin-related peptide (G**KFLHSAGKFGKAFLGEVMIG) containing a two amino acid residue deletion compared with magainin-2 was identified that had only weak antimicrobial activity. The peptide with the greatest potential for development into a therapeutically valuable anti-infective agent was CPF-B1 (GLGSLLGKAFKIGLKTVGKMMGGAPREQ) with MIC=5 microM against E. coli, MIC=5 microM against S. aureus, and MIC=25 microM against Candida albicans, and low hemolytic activity against human erythrocytes (LC(50)>200 microM). This peptide was also the most abundant antimicrobial peptide in the skin secretions. CPF-B1 was active against clinical isolates of the nosocomial pathogens, methicillin-resistant S. aureus (MRSA) and multidrug-resistant Acinetobacter baumannii (MDRAB) with MIC values in the range 4-8 microM.
Mechkarska
Milena
M
Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates.
Ahmed
Eman
E
Coquet
Laurent
L
Leprince
Jérôme
J
Jouenne
Thierry
T
Vaudry
Hubert
H
King
Jay D
JD
Conlon
J Michael
JM
D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012867:Skin / Q000378:metabolism*; D014981:Xenopus / Q000378:metabolism*; D029867:Xenopus Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D029867:Xenopus Proteins