title: Antimicrobial peptides with therapeutic potential from skin secretions of the Marsabit clawed frog Xenopus borealis (Pipidae).
abstract: 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.
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates.
authors.forename: Milena
authors.initials: M
authors.lastname: Mechkarska
authors.forename: Eman
authors.initials: E
authors.lastname: Ahmed
authors.forename: Laurent
authors.initials: L
authors.lastname: Coquet
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leprince
authors.forename: Thierry
authors.initials: T
authors.lastname: Jouenne
authors.forename: Hubert
authors.initials: H
authors.lastname: Vaudry
authors.forename: Jay D
authors.initials: JD
authors.lastname: King
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
mesh_terms: 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*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D029867:Xenopus Proteins