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Identification of a novel cathelicidin antimicrobial peptide from ducks and determination of its functional activity and antibacterial mechanism.

Gao W, Xing L, Qu P, Tan T, Yang N, Li D, Chen H, Feng X - Sci Rep (2015)

Bottom Line: The cDNA sequence of dCATH encodes a predicted 146-amino-acid polypeptide composed of a 17-residue signal peptide, a 109-residue conserved cathelin domain and a 20-residue mature peptide.Phylogenetic analysis demonstrated that dCATH is highly divergent from other avian peptides.The effects on bacterial outer and inner membranes, as examined by scanning electron microscope and transmission electron microscopy, indicate that dCATH kills microbial cells by increasing permeability, causing a loss of membrane integrity.

View Article: PubMed Central - PubMed

Affiliation: College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, P.R. China.

ABSTRACT
The family of antimicrobial peptide, cathelicidins, which plays important roles against infections in animals, has been identified from many species. Here, we identified a novel avian cathelicidin ortholog from ducks and named dCATH. The cDNA sequence of dCATH encodes a predicted 146-amino-acid polypeptide composed of a 17-residue signal peptide, a 109-residue conserved cathelin domain and a 20-residue mature peptide. Phylogenetic analysis demonstrated that dCATH is highly divergent from other avian peptides. The α-helical structure of the peptide exerted strong antimicrobial activity against a broad range of bacteria in vitro, with most minimum inhibitory concentrations in the range of 2 to 4 μM. Moreover, dCATH also showed cytotoxicity, lysing 50% of mammalian erythrocytes in the presence or absence of 10% fetal calf serum at concentrations of 32 μM or 20 μM and killing 50% HaCaT cells at a concentration of 10 μM. The effects on bacterial outer and inner membranes, as examined by scanning electron microscope and transmission electron microscopy, indicate that dCATH kills microbial cells by increasing permeability, causing a loss of membrane integrity.

No MeSH data available.


Related in: MedlinePlus

Scanning and transmission electron micrographs of E. coli 25922 and S. aureus 29213 treated with the peptide dCATH.SEM micrographs of E. coli: (A) Control, no peptide; (B) peptide-treated. SEM micrographs of S. aureus: (C) Control, no peptide; (D) peptide-treated. TEM micrographs of E. coli: (E) Control, no peptide; (F) dCATH-treated; TEM micrographs of S. aureus: (G) Control, no peptide; (H) dCATH-treated. Bacteria in mid-logarithmic phase were treated with the peptide at 1× MIC for 1 h.
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f7: Scanning and transmission electron micrographs of E. coli 25922 and S. aureus 29213 treated with the peptide dCATH.SEM micrographs of E. coli: (A) Control, no peptide; (B) peptide-treated. SEM micrographs of S. aureus: (C) Control, no peptide; (D) peptide-treated. TEM micrographs of E. coli: (E) Control, no peptide; (F) dCATH-treated; TEM micrographs of S. aureus: (G) Control, no peptide; (H) dCATH-treated. Bacteria in mid-logarithmic phase were treated with the peptide at 1× MIC for 1 h.

Mentions: The effect of the peptide dCATH on the membrane integrity of E. coli and S. aureus was examined. In the control without peptide treatment, all cells displayed a plump shape and smooth surface (Fig. 7A,C). The membrane surface of peptide-treated E. coli cells became shrunken, and cell morphology was changed (Fig. 7B). The effect of the peptide on S. aureus is shown in Fig. 7D, and the cell surface became obviously roughened and disrupted when treated with the peptide.


Identification of a novel cathelicidin antimicrobial peptide from ducks and determination of its functional activity and antibacterial mechanism.

Gao W, Xing L, Qu P, Tan T, Yang N, Li D, Chen H, Feng X - Sci Rep (2015)

Scanning and transmission electron micrographs of E. coli 25922 and S. aureus 29213 treated with the peptide dCATH.SEM micrographs of E. coli: (A) Control, no peptide; (B) peptide-treated. SEM micrographs of S. aureus: (C) Control, no peptide; (D) peptide-treated. TEM micrographs of E. coli: (E) Control, no peptide; (F) dCATH-treated; TEM micrographs of S. aureus: (G) Control, no peptide; (H) dCATH-treated. Bacteria in mid-logarithmic phase were treated with the peptide at 1× MIC for 1 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660463&req=5

f7: Scanning and transmission electron micrographs of E. coli 25922 and S. aureus 29213 treated with the peptide dCATH.SEM micrographs of E. coli: (A) Control, no peptide; (B) peptide-treated. SEM micrographs of S. aureus: (C) Control, no peptide; (D) peptide-treated. TEM micrographs of E. coli: (E) Control, no peptide; (F) dCATH-treated; TEM micrographs of S. aureus: (G) Control, no peptide; (H) dCATH-treated. Bacteria in mid-logarithmic phase were treated with the peptide at 1× MIC for 1 h.
Mentions: The effect of the peptide dCATH on the membrane integrity of E. coli and S. aureus was examined. In the control without peptide treatment, all cells displayed a plump shape and smooth surface (Fig. 7A,C). The membrane surface of peptide-treated E. coli cells became shrunken, and cell morphology was changed (Fig. 7B). The effect of the peptide on S. aureus is shown in Fig. 7D, and the cell surface became obviously roughened and disrupted when treated with the peptide.

Bottom Line: The cDNA sequence of dCATH encodes a predicted 146-amino-acid polypeptide composed of a 17-residue signal peptide, a 109-residue conserved cathelin domain and a 20-residue mature peptide.Phylogenetic analysis demonstrated that dCATH is highly divergent from other avian peptides.The effects on bacterial outer and inner membranes, as examined by scanning electron microscope and transmission electron microscopy, indicate that dCATH kills microbial cells by increasing permeability, causing a loss of membrane integrity.

View Article: PubMed Central - PubMed

Affiliation: College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, P.R. China.

ABSTRACT
The family of antimicrobial peptide, cathelicidins, which plays important roles against infections in animals, has been identified from many species. Here, we identified a novel avian cathelicidin ortholog from ducks and named dCATH. The cDNA sequence of dCATH encodes a predicted 146-amino-acid polypeptide composed of a 17-residue signal peptide, a 109-residue conserved cathelin domain and a 20-residue mature peptide. Phylogenetic analysis demonstrated that dCATH is highly divergent from other avian peptides. The α-helical structure of the peptide exerted strong antimicrobial activity against a broad range of bacteria in vitro, with most minimum inhibitory concentrations in the range of 2 to 4 μM. Moreover, dCATH also showed cytotoxicity, lysing 50% of mammalian erythrocytes in the presence or absence of 10% fetal calf serum at concentrations of 32 μM or 20 μM and killing 50% HaCaT cells at a concentration of 10 μM. The effects on bacterial outer and inner membranes, as examined by scanning electron microscope and transmission electron microscopy, indicate that dCATH kills microbial cells by increasing permeability, causing a loss of membrane integrity.

No MeSH data available.


Related in: MedlinePlus