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

• Verfasst von: Herrmann, Moritz [VerfasserIn]
• Verfasst von: Schneck, Emanuel [VerfasserIn]
• Verfasst von: Gutsmann, Thomas [VerfasserIn]
• Verfasst von: Brandenburg, Klaus [VerfasserIn]
• Verfasst von: Tanaka, Motomu [VerfasserIn]
• Titel: Bacterial lipopolysaccharides form physically cross-linked, two-dimensional gels in the presence of divalent cations
• Verf.angabe: Moritz Herrmann, Emanuel Schneck, Thomas Gutsmann, Klaus Brandenburg, Motomu Tanaka
• E-Jahr: 2015
• Jahr: 02 Jul 2015
• Umfang: 8 S.
• Fussnoten: Gesehen am 27.08.2020
• Titel Quelle: Enthalten in: Soft matter
• Ort Quelle: London : Royal Soc. of Chemistry, 2005
• Jahr Quelle: 2015
• Band/Heft Quelle: 11(2015), 30, Seite 6037-6044
• ISSN Quelle: 1744-6848
• DOI: doi:10.1039/C5SM01002K
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1727899008

Abstract

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 Ca2+. Our results demonstrated for the first time that LPSs in bacterial outer membranes can form two-dimensional elastic networks in the presence of Ca2+. Different from LPS Re monolayers, the LPS Ra monolayers showed a very similar rheological transition both in the presence and absence of Ca2+, suggesting that longer saccharide chains can form 2D physical gels even in the absence of Ca2+. 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.