1. An analog of the host-defense peptide hymenochirin-1B with potent broad-spectrum activity against multidrug-resistant bacteria and immunomodulatory properties
- Author
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J. Michael Conlon, Manju Prajeep, Milena Mechkarska, Ivan Jovanovic, Miodrag L. Lukic, Amna Al Baloushi, Agnes Sonnevend, and Gordana Radosavljevic
- Subjects
Pipidae ,Physiology ,Molecular Sequence Data ,Peptide ,Microbial Sensitivity Tests ,Gram-Positive Bacteria ,Protein Engineering ,medicine.disease_cause ,Biochemistry ,Amphibian Proteins ,Protein Structure, Secondary ,Microbiology ,Structure-Activity Relationship ,Cellular and Molecular Neuroscience ,Endocrinology ,Drug Resistance, Multiple, Bacterial ,Gram-Negative Bacteria ,medicine ,Animals ,Humans ,Immunologic Factors ,Amino Acid Sequence ,Escherichia coli ,Cells, Cultured ,chemistry.chemical_classification ,biology ,biology.organism_classification ,Antimicrobial ,Interleukin-10 ,Acinetobacter baumannii ,Citrobacter freundii ,Stenotrophomonas maltophilia ,chemistry ,Staphylococcus aureus ,Leukocytes, Mononuclear ,Interleukin-4 ,Enterobacter cloacae ,Antimicrobial Cationic Peptides - Abstract
Hymenochirin-1B (IKLSPETKDN(10)LKKVLKGAIK(20)GAIAVAKMV.NH2) is a cationic, amphipathic, α-helical, host-defense peptide, first isolated from skin secretions of the Congo clawed frog Hymenochirus boettgeri (Pipidae). Structure-activity relationships were investigated by synthesizing analogs in which the Pro(5), Glu(6) and Asp(9) on the hydrophilic face of the α-helix are substituted by one or more l-lysine or d-lysine residues. Although replacement with l-lysine generates analogs with increased antimicrobial potency against a range of Gram-positive and Gram-negative bacteria (up to 8-fold), the peptides are more hemolytic. Increasing the cationicity of hymenochirin-1B while reducing the helicity by substitutions with d-lysine generates analogs that are between 2 and 8 fold more potent than the native peptide and are equally or less hemolytic. [E6k,D9k]hymenochirin-1B represents a candidate for drug development as it shows high potency against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and a range of Gram-negative bacteria, including multidrug-resistant strains of Acinetobacter baumannii and Stenotrophomonas maltophilia (MIC in the range 0.8-3.1 μM) and NDM-1 carbapenemase-producing clinical isolates of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Citrobacter freundii (MIC in the range 3.1-6.25 μM), and low hemolytic activity (LC50=302 μM). [E6k,D9k]hymenochirin-1B, at a concentration of 2.5 μM, significantly (P
- Published
- 2013