Selective recognition and imaging of bacterial model membranes over mammalian ones by using cationic conjugated polyelectrolytes

Abstract Solubilisation of two bacterial model membranes induced by N,N-dimethyl-1-dodecanamine-N-oxide (DDAO) was studied. The first model membrane consisted of a mixture of palmitoyloleoylphosphatidylethanolamine (POPE) and palmitoyloleoylphosphatidylglycerol (POPG) in a molar ratio 0.6:0.4 mol/mol, and a second model membrane was enriched with tetraoleoylcardiolipin (TOCL) with a composition POPE-POPG-TOCL = 0.67:0.23:0.1 mol/mol/mol. Solubilisation of these model membranes was studied by static light scattering (nephelometry). Effective ratio Re (the amount of DDAO integrated into the bilayer to the amount of lipid) at different steps of the solubilisation process was determined. The molar partition coefficient of DDAO was calculated – in case of the POPE-POPG membrane, Kp = 5,300 ± 400, for the POPE-POPG-TOCL membrane, Kp = 6,500 ± 500.

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Bacterial Model Membranes Deform (resp. Persist) upon Ni2+Binding to Inner Core (resp. O-Antigen) of Lipopolysaccharides

The Journal of Physical Chemistry B ◽

10.1021/acs.jpcb.9b02762 ◽

2019 ◽

Vol 123 (19) ◽

pp. 4258-4270 ◽

Cited By ~ 1

Author(s):

HanByul Chang ◽

Karthikeyan Gnanasekaran ◽

Nathan C. Gianneschi ◽

Franz M. Geiger

Keyword(s):

Inner Core ◽

Model Membranes ◽

O Antigen ◽

Bacterial Model

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Towards the use of monofluorinated dimyristoylphosphatidylcholines as 19F NMR reporters in bacterial model membranes

Journal of Fluorine Chemistry ◽

10.1016/j.jfluchem.2017.12.009 ◽

2018 ◽

Vol 206 ◽

pp. 43-47 ◽

Cited By ~ 1

Author(s):

Marie-Claude Gagnon ◽

Paméla Ouellet ◽

Michèle Auger ◽

Jean-François Paquin

Keyword(s):

Model Membranes ◽

19F Nmr ◽

Bacterial Model

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Galleria mellonella native and analogue peptides Gm1 and ΔGm1. I) Biophysical characterization of the interaction mechanisms with bacterial model membranes

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/j.bbamem.2014.07.006 ◽

2014 ◽

Vol 1838 (10) ◽

pp. 2728-2738 ◽

Cited By ~ 9

Author(s):

Wilmar Correa ◽

Marcela Manrique-Moreno ◽

Edwin Patiño ◽

Carlos Peláez-Jaramillo ◽

Yani Kaconis ◽

...

Keyword(s):

Galleria Mellonella ◽

Model Membranes ◽

Biophysical Characterization ◽

Interaction Mechanisms ◽

Bacterial Model

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Modified Bacterial Lipids Which Alter Membrane Surface Charge Reduce Binding of Antimicrobial Peptides

10.1101/2020.04.24.057349 ◽

2020 ◽

Author(s):

Patrick W. Simcock ◽

Maike Bublitz ◽

Flaviu Cipcigan ◽

Maxim G. Ryadnov ◽

Jason Crain ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Surface Charge ◽

Membrane Surface ◽

Potential Of Mean Force ◽

Model Membranes ◽

Phosphatidyl Glycerol ◽

Bacterial Membranes ◽

Active Peptides ◽

The Relationship ◽

Membrane Surface Charge

ABSTRACTAntimicrobial peptides (AMPs) initiate killing of bacteria by binding to and destabilizing their membranes. The multiple peptide resistance factor (MprF) provides a defence mechanism for bacteria against a broad range of AMPs. MprF reduces the negative charge of both Gram-positive and Gram--negative bacterial membranes through enzymatic conversion of the anionic lipid phosphatidyl glycerol (PG) to either zwitterionic alanyl-phosphatidyl glycerol (Ala-PG) or cationic lysylphosphatidyl glycerol (Lys-PG). The resulting change in membrane charge is suggested to reduce AMP-membrane binding and hinder downstream AMP activity. Using molecular dynamics to investigate the effects of these modified lipids on AMP-binding to model membranes, we show that AMPs have substantially reduced affinity for model membranes containing Ala-PG or Lys-PG. A total of ~7000 simulations are used to define the relationship between bilayer composition and binding for 5 different membrane active peptides. The reduction of degree of interaction of a peptide with the membrane is shown to correlate with the change in membrane surface charge density. Free energy profile (potential of mean force) calculations reveal that these lipid modifications alter the energy barrier to peptide helix penetration of the bilayer. These results will enable us to guide design of novel peptides which address the issue of resistance via MprF-mediated membrane modification.

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