Effect of Cations on the Structure of Bilayers Formed by Lipopolysaccharides Isolated from Pseudomonas aeruginosa PAO1 Academic Article uri icon

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abstract

  • The asymmetric outer membrane of Gram-negative bacteria contains lipopolysaccharides (LPSs) which contribute significantly to the bacterium's surface properties and play a crucial role in regulating membrane permeability. We report on neutron diffraction studies performed on aligned, self-assembled bilayers of Na-, Ca-, and Mg-salt forms of LPS isolated from Pseudomonas aeruginosa PAO1. From the one-dimensional neutron scattering length density profiles we find that water penetrates Ca2+-LPS bilayers to a lesser extent than either Na+- or Mg2+-LPS bilayers. This differential water penetration could have implications as to how small molecules permeate the outer membrane of Gram-negative bacteria and, possibly, how nonlamellar phases are formed.

authors

  • Kučerka, Norbert
  • Papp-Szabo, Erzsebet
  • Nieh, Mu-Ping
  • Harroun, Thad A
  • Schooling, Sarah R
  • Pencer, Jeremy
  • Nicholson, Eric A
  • Beveridge, Terry J
  • Katsaras, John

publication date

  • July 2008