Multimerization of a Proline-Rich Antimicrobial Peptide, Chex-Arg20, Alters Its Mechanism of Interaction with the Escherichia coli Membrane

Wenyi Li; Neil M O'Brien-Simpson; Julien Tailhades; Namfon Pantarat; Raymond M Dawson; Laszlo Otvos Jr; Eric C Reynolds; Frances Separovic; Mohammed Akhter Hossain; John D Wade

doi:10.1016/j.chembiol.2015.08.011

Multimerization of a Proline-Rich Antimicrobial Peptide, Chex-Arg20, Alters Its Mechanism of Interaction with the Escherichia coli Membrane

Chem Biol. 2015 Sep 17;22(9):1250-8. doi: 10.1016/j.chembiol.2015.08.011.

Authors

Affiliations

¹ School of Chemistry, University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC 3010, Australia.
² Oral Health CRC, Melbourne Dental School, University of Melbourne, VIC 3010, Australia; Bio21 Institute, University of Melbourne, VIC 3010, Australia.
³ The Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC 3010, Australia.
⁴ Oral Health CRC, Melbourne Dental School, University of Melbourne, VIC 3010, Australia.
⁵ Land Division, Defence Science and Technology Organization, Fishermans Bend, VIC 3207, Australia.
⁶ Department of Biology, Temple University, Philadelphia, PA 19122, USA; Institute of Medical Microbiology, Semmelweis University, Budapest 1089, Hungary.
⁷ School of Chemistry, University of Melbourne, VIC 3010, Australia; Bio21 Institute, University of Melbourne, VIC 3010, Australia.
⁸ School of Chemistry, University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC 3010, Australia. Electronic address: akhter.hossain@florey.edu.au.
⁹ School of Chemistry, University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC 3010, Australia. Electronic address: john.wade@florey.edu.au.

PMID: 26384569
DOI: 10.1016/j.chembiol.2015.08.011

Abstract

A3-APO, a de novo designed branched dimeric proline-rich antimicrobial peptide (PrAMP), is highly effective against a variety of in vivo bacterial infections. We undertook a selective examination of the mechanism for the Gram-negative Escherichia coli bacterial membrane interaction of the monomer (Chex-Arg20), dimer (A3-APO), and tetramer (A3-APO disulfide-linked dimer). All three synthetic peptides were effective at killing E. coli. However, the tetramer was 30-fold more membrane disruptive than the dimer while the monomer showed no membrane activity. Using flow cytometry and high-resolution fluorescent microscopy, it was observed that dimerization and tetramerization of the Chex-Arg20 monomer led to an alteration in the mechanism of action from non-lytic/membrane hyperpolarization to membrane disruption/depolarization. Our findings show that the membrane interaction and permeability of Chex-Arg20 was altered by multimerization.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antimicrobial Cationic Peptides / chemical synthesis
Antimicrobial Cationic Peptides / pharmacokinetics
Antimicrobial Cationic Peptides / pharmacology*
Dimerization
Escherichia coli / drug effects*
Escherichia coli / metabolism*
Flow Cytometry
Membrane Proteins / chemistry
Membrane Proteins / metabolism
Microbial Sensitivity Tests
Microscopy, Fluorescence
Peptides / chemical synthesis
Peptides / pharmacokinetics
Proline / chemistry
Proline / metabolism
Proline-Rich Protein Domains
Structure-Activity Relationship

Substances

Antimicrobial Cationic Peptides
Membrane Proteins
Peptides
Proline