Effect of Secondary Structure on Biological Activities of Antimicrobial Peptides
http://repository.vnu.edu.vn/handle/VNU_123/938
A
15-mer cationic α-helical antibacterial peptide was used as the framework to
study the effect of peptide secondary structure on antimicrobial activities.
We
designed an α-helical peptide with higher helical propensity compared with the
original peptide, a β-sheet peptide and a random coiled peptide without
changing the originalamino acid composition of the peptide sequence.
Three
truncated peptides were also designed.
The
secondary structures of the peptides were determined by circular dichroism
spectra both in aqueous solution and in hydrophobic environment.
The
biological activities of the peptides were detected against three Gram-negative
bacterial strains, three Gram-positive bacterial strains and human red blood
cells. The results showed that the two helical peptides exhibited comparable
antibacterial activities but their hemolytic potency (cytotoxicity) varied from
extreme hemolysis to no hemolysis, which was positively correlated with their
helical propensity.
The
β-sheet peptide partially lost both of the biological activities.
The
random coiled peptide with the lowest improvement in hemolytic activity showed
comparable antibacterial activity against Gram-positive bacteria but weaker
antibacterial activity against Gram-negative bacteria.
Truncated
peptides showed inevitable weaker antimicrobial activity compared to the parent
peptide.
Our
results show that peptide secondary structure is strongly correlated with
hemolytic activity and relatively less correlated with antimicrobial activity,
which provides an insight into the mechanism of action of the antimicrobial
peptide.
Title: | Effect of Secondary Structure on Biological Activities of Antimicrobial Peptides |
Authors: | Mai Xuan, Thanh |
Keywords: | Antimicrobial peptide;secondary structure;specificity;mechanism of action |
Issue Date: | 2015 |
Publisher: | ĐHQGHN |
Series/Report no.: | Vol. 31, No. 2 (2015) 44-53; |
Abstract: | A 15-mer cationic α-helical antibacterial peptide was used as the framework to study the effect of peptide secondary structure on antimicrobial activities. We designed an α-helical peptide with higher helical propensity compared with the original peptide, a β-sheet peptide and a random coiled peptide without changing the originalamino acid composition of the peptide sequence. Three truncated peptides were also designed. The secondary structures of the peptides were determined by circular dichroism spectra both in aqueous solution and in hydrophobic environment. The biological activities of the peptides were detected against three Gram-negative bacterial strains, three Gram-positive bacterial strains and human red blood cells. The results showed that the two helical peptides exhibited comparable antibacterial activities but their hemolytic potency (cytotoxicity) varied from extreme hemolysis to no hemolysis, which was positively correlated with their helical propensity. The β-sheet peptide partially lost both of the biological activities. The random coiled peptide with the lowest improvement in hemolytic activity showed comparable antibacterial activity against Gram-positive bacteria but weaker antibacterial activity against Gram-negative bacteria. Truncated peptides showed inevitable weaker antimicrobial activity compared to the parent peptide. Our results show that peptide secondary structure is strongly correlated with hemolytic activity and relatively less correlated with antimicrobial activity, which provides an insight into the mechanism of action of the antimicrobial peptide. |
URI: | http://repository.vnu.edu.vn/handle/VNU_123/938 |
ISSN: | 0866 - 86 12 |
Appears in Collections: | Natural Sciences and Technology |
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