Probing protein sequences as sources for encrypted antimicrobial peptides

Brand, G.D., Magalhães, M.T.Q., Tinoco, M.L.P., Aragão, F.J.L., Nicoli, J., Kelly, S. , Cooper, A. and Bloch Jr, C. (2012) Probing protein sequences as sources for encrypted antimicrobial peptides. PLoS ONE, 7(9), e45848. (doi: 10.1371/journal.pone.0045848)

Available under License Creative Commons Attribution.



Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Kelly, Dr Sharon and Brand, Mr Guilherme and Cooper, Professor Alan
Authors: Brand, G.D., Magalhães, M.T.Q., Tinoco, M.L.P., Aragão, F.J.L., Nicoli, J., Kelly, S., Cooper, A., and Bloch Jr, C.
Subjects:Q Science > QD Chemistry
Q Science > QH Natural history > QH345 Biochemistry
College/School:College of Science and Engineering > School of Chemistry
Journal Name:PLoS ONE
Publisher:Public Library of Science
ISSN (Online):1932-6203
Published Online:28 September 2012
Copyright Holders:Copyright © 2012 The Authors
First Published:First published in PLoS ONE 7(9):e45848
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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