Journal article

Fluorescent Ion Efflux Screening Assay for Determining Membrane-Active Peptides

Neil M O'Brien-Simpson, Wenyi Li, Namfon Pantarat, Mohammed Akhter Hossain, Frances Separovic, John D Wade, Eric C Reynolds



A major global health threat is the emergence of antibiotic-resistant microbes. Coupled with a lack of development of modified antibiotics, there is a need to develop new antimicrobial molecules and screening assays for them. In this study, we provide proof of concept that a large unilamellar vesicle (LUV) method used to study chloride ion efflux facilitated by ionophores and surfactant-like molecules that disrupt membrane integrity can be adapted to identify membrane-interactive antimicrobial peptides (AMPs) and to screen relative activity of AMPs. Lucigenin was encapsulated in LUVs in the presence of Cl-ion (NaCl), which quenches fluorescence, and then incubated with AMPs in 100mM NaNO3 bu..

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Awarded by Australian Research Council (ARC)

Awarded by National Health and Medical Research Council (NHMRC)

Funding Acknowledgements

We gratefully acknowledge support of the studies undertaken in the authors' laboratory by an Australian Research Council (ARC) Discovery Project grant (DP150103522) to J.D.W. and M.A.H., and National Health and Medical Research Council (NHMRC) Project grants (APP1029878) to N.M.O'B.S. and (APP1008106) to E.C.R. and N.M. O'B.S. This work was also supported by the Australian Government, Department of Industry, Innovation and Science. J.D.W. is an NHMRC (Australia) Principal Research Fellow. W.L. is the recipient of a Melbourne International Research Scholarship (MIRS) PhD award and Dr Albert Shimmins Postgraduate Writing-Up award (University of Melbourne). Research at The Florey Institute of Neuroscience and Mental Health (FINMH) was also supported by the Victorian Government's Operational Infrastructure Support Program.