Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin

Show simple item record Taute, Helena Bester, Megan Jean Neitz, A.W.H. (Albert Walter Herman) Gaspar, A.R.M. (Anabella Regina Marques) 2015-10-30T07:30:10Z 2015-09
dc.description.abstract Os and Os-C are two novel antimicrobial peptides, derived from a tick defensin, which have been shown to have a larger range of antimicrobial activity than the parent peptide, OsDef2. The aim of this study was to determine whether the peptides Os and Os-C are mainly membrane acting, or if these peptides have possible additional intracellular targets in Escherichia coli and Bacillus subtilis. Transmission electron microscopy revealed that both peptides adversely affected intracellular structure of both bacteria causing different degrees of granulation of the intracellular contents. At the minimum bactericidal concentrations, permeabilization as determined with the SYTOX green assay seemed not to be the principle mode of killing when compared to melittin. However, fluorescent triple staining indicated that the peptides caused permeabilization of stationary phase bacteria and TEM indicated membrane effects. Studies using fluorescently labeled peptides revealed that the membrane penetrating activity of Os and Os-C was similar to buforin II. Os-C was found to associate with the septa of B. subtilis. Plasmid binding studies showed that Os and Os-C binds E. coli plasmid DNA at a similar charge ratio as melittin. These studies suggest membrane activity for Os and Os-C with possible intracellular targets such as DNA. The differences in permeabilization at lower concentrations and binding to DNA between Os and Os-C, suggest that the two peptides have dissimilar modes of action. en_ZA
dc.description.embargo 2016-09-30
dc.description.librarian hb2015 en_ZA
dc.description.sponsorship Medical Research Council and the National Research Foundation of South Africa. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Taute, H, Bester, MJ, Neitz, AWH & Gaspar, ARM 2015, 'Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin', Peptides, vol. 71, pp. 179-187. en_ZA
dc.identifier.issn 0196-9781 (print)
dc.identifier.issn 1873-5169 (online)
dc.identifier.other 10.1016/j.peptides.2015.07.017
dc.language.iso en en_ZA
dc.publisher Elsevier en_ZA
dc.rights © 2015 Elsevier Inc. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Peptides. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Peptides, vol. 71, pp. 179-187, 2015. doi : 10.1016/j.peptides.2015.07.017. en_ZA
dc.subject Defensin en_ZA
dc.subject Tick en_ZA
dc.subject C-terminus en_ZA
dc.subject Membrane permeabilization en_ZA
dc.subject Mode of action en_ZA
dc.subject DNA binding en_ZA
dc.title Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin en_ZA
dc.type Postprint Article en_ZA

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