Limits...
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

(A) Hemolytic activity of the peptides. Hemolytic activity was evaluated by incubating individual peptide in serial 2-fold dilutions with freshly isolated human erythrocytes in the absence (dCATH (a)) or presence (dCATH (b)) of 10% FBS at 37 °C for 2 h, followed by measuring the released hemoglobin at 405 nm. No FBS was added in the hemolytic activity of melittin (*P < 0.05; **P < 0.01; by unpaired t test. The blue * indicates the difference between melittin and dCATH (a), the red ones means the difference between dCATH (a) and dCATH (b)). (B) Cytotoxic activity of the peptides. HaCat cells were used to evaluate the toxicity of the peptides to mammalian cells, and measured the released MTT at 492 nm. All the tests were performed three times (*P < 0.05; **P < 0.01; by unpaired t test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4660463&req=5

f4: (A) Hemolytic activity of the peptides. Hemolytic activity was evaluated by incubating individual peptide in serial 2-fold dilutions with freshly isolated human erythrocytes in the absence (dCATH (a)) or presence (dCATH (b)) of 10% FBS at 37 °C for 2 h, followed by measuring the released hemoglobin at 405 nm. No FBS was added in the hemolytic activity of melittin (*P < 0.05; **P < 0.01; by unpaired t test. The blue * indicates the difference between melittin and dCATH (a), the red ones means the difference between dCATH (a) and dCATH (b)). (B) Cytotoxic activity of the peptides. HaCat cells were used to evaluate the toxicity of the peptides to mammalian cells, and measured the released MTT at 492 nm. All the tests were performed three times (*P < 0.05; **P < 0.01; by unpaired t test).

Mentions: The hemolytic activity of the peptide against human erythrocytes was determined as a measure of toxicity to mammalian cells. Figure 4A showed the hemolytic activity toward human erythrocytes, with 50% killing of mammalian erythrocytes occurring at 20 μM and 32 μM for dCATH in the absence (a) or presence (b) of 10% fetal calf serum (FBS), respectively. In contrast, melittin used as a control peptide caused 50% killing of mammalian erythrocytes occurring at 5 μM. The hemolytic activity of dCATH was reduced in the presence of 10% FBS.


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)

(A) Hemolytic activity of the peptides. Hemolytic activity was evaluated by incubating individual peptide in serial 2-fold dilutions with freshly isolated human erythrocytes in the absence (dCATH (a)) or presence (dCATH (b)) of 10% FBS at 37 °C for 2 h, followed by measuring the released hemoglobin at 405 nm. No FBS was added in the hemolytic activity of melittin (*P < 0.05; **P < 0.01; by unpaired t test. The blue * indicates the difference between melittin and dCATH (a), the red ones means the difference between dCATH (a) and dCATH (b)). (B) Cytotoxic activity of the peptides. HaCat cells were used to evaluate the toxicity of the peptides to mammalian cells, and measured the released MTT at 492 nm. All the tests were performed three times (*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

f4: (A) Hemolytic activity of the peptides. Hemolytic activity was evaluated by incubating individual peptide in serial 2-fold dilutions with freshly isolated human erythrocytes in the absence (dCATH (a)) or presence (dCATH (b)) of 10% FBS at 37 °C for 2 h, followed by measuring the released hemoglobin at 405 nm. No FBS was added in the hemolytic activity of melittin (*P < 0.05; **P < 0.01; by unpaired t test. The blue * indicates the difference between melittin and dCATH (a), the red ones means the difference between dCATH (a) and dCATH (b)). (B) Cytotoxic activity of the peptides. HaCat cells were used to evaluate the toxicity of the peptides to mammalian cells, and measured the released MTT at 492 nm. All the tests were performed three times (*P < 0.05; **P < 0.01; by unpaired t test).
Mentions: The hemolytic activity of the peptide against human erythrocytes was determined as a measure of toxicity to mammalian cells. Figure 4A showed the hemolytic activity toward human erythrocytes, with 50% killing of mammalian erythrocytes occurring at 20 μM and 32 μM for dCATH in the absence (a) or presence (b) of 10% fetal calf serum (FBS), respectively. In contrast, melittin used as a control peptide caused 50% killing of mammalian erythrocytes occurring at 5 μM. The hemolytic activity of dCATH was reduced in the presence of 10% FBS.

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