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Publication
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| Title of Article |
A novel antibacterial peptide derived from Crocodylus
siamensis haemoglobin hydrolysate induces membrane
permeabilization causing iron dysregulation, oxidative
stress and bacterial death |
| Date of Acceptance |
6 July 2017 |
| Journal |
| Title of Journal |
Journal of Applied Microbiology |
| Standard |
ISI |
| Institute of Journal |
WILEY |
| ISBN/ISSN |
1365-2672 |
| Volume |
2017 |
| Issue |
123 |
| Month |
october |
| Year of Publication |
2017 |
| Page |
819-831 |
| Abstract |
Aims: A novel antibacterial peptide from Crocodylus siamensis haemoglobin
hydrolysate (CHH) was characterized for antimicrobial activity.
Methods and Results: CHHs were hydrolysed for 2 h (2 h-CHH), 4 h (4
h-CHH), 6 h (6 h-CHH) and 8 h (8 h-CHH). The 8 h-CHH showed
antibacterial activity against Escherichia coli, Staphylococcus aureus, Klebsiella
pneumoniae and Pseudomonas aeruginosa at concentrations of 20, 20, 20 and
10 mg ml
1 (w/v) respectively. Fluorescent microscopy revealed that the 8 h-
CHH had bactericidal activity against E. coli and P. aeruginosa.
b-galactosidase assay supported by RT-qPCR demonstrated that the 8 h-CHH
resulted in differential expression of genes involved in iron homeostasis (ftnA
and bfd) and oxidative stress (sodA, soxR and oxyR). Siderophore assay
indicated that the 8 h-CHH also impaired siderophore production with
diminished expression of pvdF. This pattern of gene expression suggests that
the 8 h-CHH triggers the release of free ferric ions in the cytoplasm.
However, decreased expression of genes associated with the SOS response
(recA and lexA) in combination with neutral comet revealed that no DNA
damage was caused by 8 h-CHH. Membrane permeabilization assay indicated
that 8 h-CHH caused membrane leakage thought to mediate the antibacterial
and iron-stress responses observed, due to loss of regulated iron transport.
The novel active peptide from 8 h-CHH was determined as
QAIIHNEKVQAHGKKVL (QL17), with 41% hydrophobicity and +2 net
charge.
Conclusions: The QAIIHNEKVQAHGKKVL fragment of C. siamensis
haemoglobin is antibacterial via a mechanism that likely relies on iron
dysregulation and oxidative stress which results in bacterial death.
Significance and Impact of the Study: We have described for the first time, a
novel peptide derived from C. siamensis haemoglobin hydrolysate that has the
potential to be developed as a novel antimicrobial peptide. |
| Keyword |
antibacterial peptide, Crocodylus siamensis, haemoglobin hydrolysate, iron dysregulation, membrane permeabilization, oxidative stress. |
| Author |
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| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
true |
| Part of thesis |
true |
| Attach file |
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| Citation |
0
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Journal Publication
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