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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

The outer membrane permeability of the peptide dCATH.The outer membrane permeability of E. coli UB1005 in the presence of different peptide concentrations (dCATH, ME-26) was determined using the fluorescent dye (NPN) assay. The NPN uptake was monitored at an excitation wavelength of 350 nm and an emission wavelength of 420 nm (*P < 0.05; **P < 0.01; by unpaired t test).
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f5: The outer membrane permeability of the peptide dCATH.The outer membrane permeability of E. coli UB1005 in the presence of different peptide concentrations (dCATH, ME-26) was determined using the fluorescent dye (NPN) assay. The NPN uptake was monitored at an excitation wavelength of 350 nm and an emission wavelength of 420 nm (*P < 0.05; **P < 0.01; by unpaired t test).

Mentions: An uptake assay was used to investigate the ability of the peptide dCATH to disturb bacterial outer membrane permeabilization, and E. coli UB1005 was used as the model. As shown in Fig. 5, dCATH and melittin were demonstrated to permeabilize the outer membrane of E. coli in a dose-dependent manner, as observed by an increase in 1-N-phenylnaphthylamine (NPN) fluorescence. The peptide was able to permeabilize the outer membrane even at concentrations below the MIC. Compared with melittin, dCATH possesses a stronger ability (P < 0.01) to permeabilize the outer membrane at each concentration.


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)

The outer membrane permeability of the peptide dCATH.The outer membrane permeability of E. coli UB1005 in the presence of different peptide concentrations (dCATH, ME-26) was determined using the fluorescent dye (NPN) assay. The NPN uptake was monitored at an excitation wavelength of 350 nm and an emission wavelength of 420 nm (*P < 0.05; **P < 0.01; by unpaired t test).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: The outer membrane permeability of the peptide dCATH.The outer membrane permeability of E. coli UB1005 in the presence of different peptide concentrations (dCATH, ME-26) was determined using the fluorescent dye (NPN) assay. The NPN uptake was monitored at an excitation wavelength of 350 nm and an emission wavelength of 420 nm (*P < 0.05; **P < 0.01; by unpaired t test).
Mentions: An uptake assay was used to investigate the ability of the peptide dCATH to disturb bacterial outer membrane permeabilization, and E. coli UB1005 was used as the model. As shown in Fig. 5, dCATH and melittin were demonstrated to permeabilize the outer membrane of E. coli in a dose-dependent manner, as observed by an increase in 1-N-phenylnaphthylamine (NPN) fluorescence. The peptide was able to permeabilize the outer membrane even at concentrations below the MIC. Compared with melittin, dCATH possesses a stronger ability (P < 0.01) to permeabilize the outer membrane at each concentration.

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