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Salt-Tolerant antifungal and antibacterial activities of the corn defensin ZmD32

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posted on 11.02.2021, 23:49 by Bomai K Kerenga, James McKenna, Peta J Harvey, Pedro Quimbar Dominguez, Donovan Garcia-Ceron, Fung Lay, Thanh Phan, Prem Veneer, Shaily Vasa, Kathy Parisi, Thomas Shafee, Nicole Van Der Weerden, Mark Hulett, David J Craik, Marilyn Anderson, Mark Bleackley
Copyright © 2019 Kerenga, McKenna, Harvey, Quimbar, Garcia-Ceron, Lay, Phan, Veneer, Vasa, Parisi, Shafee, van der Weerden, Hulett, Craik, Anderson and Bleackley. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Pathogenic microbes are developing resistance to established antibiotics, making the development of novel antimicrobial molecules paramount. One major resource for discovery of antimicrobials is the arsenal of innate immunity molecules that are part of the first line of pathogen defense in many organisms. Gene encoded cationic antimicrobial peptides are a major constituent of innate immune arsenals. Many of these peptides exhibit potent antimicrobial activity in vitro. However, a major hurdle that has impeded their development for use in the clinic is the loss of activity at physiological salt concentrations, attributed to weakening of the electrostatic interactions between the cationic peptide and anionic surfaces of the microbial cells in the presence of salt. Using plant defensins we have investigated the relationship between the charge of an antimicrobial peptide and its activity in media with elevated salt concentrations. Plant defensins are a large class of antifungal peptides that have remarkable stability at extremes of pH and temperature as well as resistance to protease digestion. A search of a database of over 1200 plant defensins identified ZmD32, a defensin from Zea mays, with a predicted charge of +10.1 at pH 7, the highest of any defensin in the database. Recombinant ZmD32 retained activity against a range of fungal species in media containing elevated concentrations of salt. In addition, ZmD32 was active against Candida albicans biofilms as well as both Gram negative and Gram-positive bacteria. This broad spectrum antimicrobial activity, combined with a low toxicity on human cells make ZmD32 an attractive lead for development of future antimicrobial molecules.

Funding

This work was funded by an Australian Research Council grant to MA and NW (DP150104386) and MA (DP160100309). JM is a Commonwealth Scientific and Industrial Research Organisation Science and Industry Endowment Fund STEM Fellow. DC is an Australian Research Council Australian Laureate Fellow (FL150100146).

Australian Research Council | DP150104386

Australian Research Council | DP160100309

Australian Research Council | FL150100146

History

Publication Date

12/04/2019

Journal

Frontiers in Microbiology

Volume

10

Article Number

795

Pagination

13p.

Publisher

Frontiers Media S.A.

ISSN

1664-302X

Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.