Membrane-active mechanism of LFchimera against Burkholderia pseudomallei and Burkholderia thailandensis

• Published in: Biometals Vol. 27; no. 5; pp. 949 - 956
• Main Authors: Kanthawong, Sakawrat, Puknun, Aekkalak, Bolscher, Jan G. M., Nazmi, Kamran, van Marle, Jan, de Soet, Johannes J., Veerman, Enno C. I., Wongratanacheewin, Surasakdi, Taweechaisupapong, Suwimol
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2014; Springer Nature B.V
• Subjects: Amino Acid Sequence; Animals; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - pharmacology; Bacteria; Biochemistry; Biomedical and Life Sciences; Burkholderia; Burkholderia - drug effects; Burkholderia - metabolism; Burkholderia - ultrastructure; Burkholderia pseudomallei; Burkholderia pseudomallei - drug effects; Burkholderia pseudomallei - metabolism; Burkholderia pseudomallei - ultrastructure; Burkholderia thailandensis; Cattle; Cell Biology; Cell Membrane - drug effects; Freeze Fracturing; Hemolysis - drug effects; Humans; Killing; Kinetics; Lactoferrin - chemistry; Lactoferrin - genetics; Lactoferrin - pharmacology; Leakage; Life Sciences; Medicine/Public Health; Membranes; Microbiology; Molecular Sequence Data; Nucleotides; Pathogens; Peptide Fragments - chemistry; Peptide Fragments - genetics; Peptide Fragments - pharmacology; Pharmacology/Toxicology; Plant Physiology; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - pharmacology; Species Specificity; Lactoferrin; Antimicrobial peptide; LFchimera
• ISSN: 0966-0844; 1572-8773
• DOI: 10.1007/s10534-014-9760-5

LFchimera, a construct combining two antimicrobial domains of bovine lactoferrin, lactoferrampin265–284 and lactoferricin17–30, possesses strong bactericidal activity. As yet, no experimental evidence was presented to evaluate the mechanisms of LFchimera against
Burkholderia
isolates. In this study we analyzed the killing activity of LFchimera on the category B pathogen
Burkholderia
pseudomallei
in comparison to the lesser virulent
Burkholderia thailandensis
often used as a model for the highly virulent
B. pseudomallei.
Killing kinetics showed that
B. thailandensis
E264 was more susceptible for LFchimera than
B. pseudomallei
1026b. Interestingly the bactericidal activity of LFchimera appeared highly pH dependent;
B. thailandensis
killing was completely abolished at and below pH 6.4. FITC-labeled LFchimera caused a rapid accumulation within 15 min in the cytoplasm of both bacterial species. Moreover, freeze-fracture electron microscopy demonstrated extreme effects on the membrane morphology of both bacterial species within 1 h of incubation, accompanied by altered membrane permeability monitored as leakage of nucleotides. These data indicate that the mechanism of action of LFchimera is similar for both species and encompasses disruption of the plasma membrane and subsequently leakage of intracellular nucleotides leading to cell dead.