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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

Cytoplasmic membrane electrical potential.The cytoplasmic membrane potential variation of E. coli UB1005 treated by peptides (dCATH, ME-26), as assessed by release of the membrane potential-sensitive dye diSC3-5.
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f6: Cytoplasmic membrane electrical potential.The cytoplasmic membrane potential variation of E. coli UB1005 treated by peptides (dCATH, ME-26), as assessed by release of the membrane potential-sensitive dye diSC3-5.

Mentions: Upon permeabilization and disruption of the cytoplasmic membrane, the membrane potential is dissipated and 3,3′-Dipropylthiadicarbocyanine iodide (diSC3-5) is released into the buffer, which results in an increase in fluorescence that can be detected by fluorescence spectrometry. As shown in Fig. 6, the membrane depolarization was measured after peptide addition. dCATH at its 1× or 2× MIC concentration was more effective and rapid at permeabilizing the membrane than melittin at 1× MIC concentration (P < 0.01). dCATH depolarized the bacterial cytoplasmic membrane in a dose-dependent manner.


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)

Cytoplasmic membrane electrical potential.The cytoplasmic membrane potential variation of E. coli UB1005 treated by peptides (dCATH, ME-26), as assessed by release of the membrane potential-sensitive dye diSC3-5.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Cytoplasmic membrane electrical potential.The cytoplasmic membrane potential variation of E. coli UB1005 treated by peptides (dCATH, ME-26), as assessed by release of the membrane potential-sensitive dye diSC3-5.
Mentions: Upon permeabilization and disruption of the cytoplasmic membrane, the membrane potential is dissipated and 3,3′-Dipropylthiadicarbocyanine iodide (diSC3-5) is released into the buffer, which results in an increase in fluorescence that can be detected by fluorescence spectrometry. As shown in Fig. 6, the membrane depolarization was measured after peptide addition. dCATH at its 1× or 2× MIC concentration was more effective and rapid at permeabilizing the membrane than melittin at 1× MIC concentration (P < 0.01). dCATH depolarized the bacterial cytoplasmic membrane in a dose-dependent manner.

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