Bacterial lipopolysaccharides form physically cross-linked, two-dimensional gels in the presence of divalent cations

We established a bacterial membrane model with monolayers of bacterial lipopolysaccharides (LPS Re and LPS Ra) and quantified their viscoelastic properties by using an interfacial stress rheometer coupled to a Langmuir film balance. LPS Re monolayers exhibited purely viscous behaviour in the absence...

Full description

Saved in:
Bibliographic Details
Published in:Soft matter 2015-08, Vol.11 (30), p.6037-6044
Main Authors: Herrmann, Moritz, Schneck, Emanuel, Gutsmann, Thomas, Brandenburg, Klaus, Tanaka, Motomu
Format: Article
Language:English
Subjects:
Bacteria
Bacteria - chemistry
Biophysical Phenomena
Calcium - chemistry
Cations, Divalent - chemistry
Cross-Linking Reagents - chemistry
Gels
Ions - chemistry
Lipopolysaccharides - chemistry
Membranes
Monitors
Monolayers
Peptides
Peptides - chemistry
Rheometers
Two dimensional
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We established a bacterial membrane model with monolayers of bacterial lipopolysaccharides (LPS Re and LPS Ra) and quantified their viscoelastic properties by using an interfacial stress rheometer coupled to a Langmuir film balance. LPS Re monolayers exhibited purely viscous behaviour in the absence of calcium ions, while the same monolayers underwent a viscous-to-elastic transition upon compression in the presence of Ca(2+). Our results demonstrated for the first time that LPSs in bacterial outer membranes can form two-dimensional elastic networks in the presence of Ca(2+). Different from LPS Re monolayers, the LPS Ra monolayers showed a very similar rheological transition both in the presence and absence of Ca(2+), suggesting that longer saccharide chains can form 2D physical gels even in the absence of Ca(2+). By exposure of the monolayers to the antimicrobial peptide protamine, we could directly monitor the differences in resistance of bacterial membranes according to the presence of calcium.
ISSN:1744-683X
1744-6848
DOI:10.1039/c5sm01002k