Details

Autor(en) / Beteiligte

• Herrmann, Moritz
• Schneck, Emanuel
• Gutsmann, Thomas
• Brandenburg, Klaus
• Tanaka, Motomu

Titel

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

Ist Teil von

• Soft matter, 2015-08, Vol.11 (30), p.6037-6044

Ort / Verlag

England

Erscheinungsjahr

2015

Quelle

MEDLINE

Beschreibungen/Notizen

• 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.