Examining the creation and destruction of model bacterial surfaces

Bacteria are differentiated into two main groups, Gram-positive or Gram-negative, based on the Gram stain which detects the thick peptidoglycan cell wall of gram positive bacteria.Gram-negative bacteria are of particular biomedical and technological interest due to their role in disease, the increasing antibiotic resistance if some species and their utility in many biotechnological processes. The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS is a polyanionic molecule, with numerous phosphate groups present in the Lipid A and core oligosaccharide regions. We have attempted to create GNB-OM assays which are amenable to molecular level characterisation. These systems are asymmetric phospholipid : lipopolysaccharide membranes deposited at the solid/liquid interface and consist of either solid supported bilayers at the silicon/water interface or floating supported bilayers at the gold/water interface. The analysis of these membrane models by neutron reflectometry has provided new insights into the OM and interactions with it. Examples of this include providing conformation of the activity of anti-bacterial proteins, the role of the lipopolysaccharide polysaccharide chains in protecting the bacterium and the importance of divalent cations in stabilising the OM structure.

Keywords

Bacteria, Phospholipids, Lipopolysaccharides, Peptides, Oligosaccharides, Neutron diffraction

Citation

Clifton, L., Skoda, M., Hughes, A., Holt, S., & Lakey, J. (2017). Examining the creation and destruction of model bacterial surfaces. Paper presented at ICNS 2017 (International Conference on Neutron Scattering), Daejeon, South Korea, 9 to 13 July 2017. Retrieved from: http://www.icns2017.org/program.php

URI

Retrieved from: http://www.icns2017.org/program.php
https://apo.ansto.gov.au/dspace/handle/10238/11374

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