Structural and functional characterization of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi

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dc.contributor.author Prinsloo, Lezaan
dc.contributor.author Naidoo, Alex
dc.contributor.author Serem, June Cheptoo
dc.contributor.author Taute, Helena
dc.contributor.author Sayed, Yasien
dc.contributor.author Bester, Megan Jean
dc.contributor.author Neitz, A.W.H. (Albert Walter Herman)
dc.contributor.author Gaspar, A.R.M. (Anabella Regina Marques)
dc.date.accessioned 2014-05-08T06:15:59Z
dc.date.available 2014-05-08T06:15:59Z
dc.date.issued 2013-05
dc.description.abstract Tick defensins may serve as templates for the development of multifunctional peptides. The purpose of this study was to evaluate shorter peptides derived from tick defensin isoform 2 (OsDef2) in terms of their antibacterial, antioxidant, and cytotoxic activities. We compared the structural and functional properties of a synthetic peptide derived from the carboxy-terminal of the parent peptide (Os) to that of an analogue in which the three cysteine residues were omitted (Os–C). Here, we report that both peptides were bactericidal (MBC values ranging from 0.94–15mg/ml) to both Gram-positive and Gram-negative bacteria, whereas the parent peptide only exhibited Gram-positive antibacterial activity. The Os peptide was found to be two-fold more active than Os–C against three of the four tested bacteria but equally active against Staphylococcus aureus. Os showed rapid killing kinetics against both Escherichia coli and Bacillus subtilis, whereas Os–C took longer, suggesting different modes of action. Scanning electron microscopy showed that in contrast to melittin for which blebbing of bacterial surfaces was observed, cells exposed to either peptide appeared flattened and empty. Circular dichroism data indicated that in a membrane-mimicking environment, the cysteine-containing peptide has a higher a-helical content. Both peptides were found to be non-toxic to mammalian cells. Moreover, the peptides displayed potent antioxidant activity and were 12 times more active than melittin. Multifunctional peptides hold potential for a wide range of clinical applications and further investigation into their mode of antibacterial and antioxidant properties is therefore warranted. en_US
dc.description.librarian hb2014 en_US
dc.description.sponsorship Medical Research Council of South Africa,the National Research Foundation of South Africa, and the University of Pretoria en_US
dc.description.uri http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-1387 en_US
dc.identifier.citation Prinsloo, L, Naidoo, A, Serem, J, Taute, H, Sayed, Y, Bester, MJ, Neitz, AWH & Gaspar, ARM 2013, 'Structural and functional characterization of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi', Journal of Peptide Science, vol. 19, no. 5, pp. 325-332. en_US
dc.identifier.issn 1075-2617 (print)
dc.identifier.issn 1099-1387 (online)
dc.identifier.other 10.1002/psc.2505
dc.identifier.uri http://hdl.handle.net/2263/39717
dc.language.iso en en_US
dc.publisher Wiley en_US
dc.rights © 2013 European Peptide Society and John Wiley & Sons, Ltd. This is the pre-peer reviewed version of the following article : Structural and functional characterization of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi in Journal of Peptide Science, vol. 19, no.5, pp. 325-332, 2013. doi : 10.1002/psc.2505 which has been published in final form at : http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-1387 en_US
dc.subject Antimicrobial peptide (AMP) en_US
dc.subject Antioxidant en_US
dc.subject Tick en_US
dc.subject Defensin en_US
dc.subject Synthetic peptide en_US
dc.subject Carboxy-terminal en_US
dc.subject Multifunctional en_US
dc.title Structural and functional characterization of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi en_US
dc.type Preprint Article en_US


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