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Ganglioside Extraction, Purification and Profiling
10:05

Ganglioside Extraction, Purification and Profiling

Published on: March 12, 2021

Cholera toxin assault on lipid monolayers containing ganglioside GM1

C E Miller1, J Majewski, R Faller

  • 1Biophysics Graduate Group, University of California, Davis, California 95616, USA.

Biophysical Journal
|June 11, 2004
PubMed

Insights

Cholera toxin binding to cell membranes causes lipid packing alterations. This structural change, observed using neutron reflectivity, may facilitate toxin entry into target cells.

Area of Science:

  • Biophysics
  • Molecular Biology
  • Membrane Biophysics

Background:

  • Bacterial toxins utilize specific membrane interactions for cellular entry.
  • Understanding toxin-membrane interactions is crucial for developing therapeutic strategies.

Purpose of the Study:

  • To characterize the structural changes in lipid monolayers upon cholera toxin binding.
  • To elucidate the role of lipid packing in toxin membrane translocation.

Main Methods:

  • Neutron reflectivity was employed to analyze mixed DPPE:GM(1) lipid monolayers.
  • Monte Carlo simulations were used to model monolayer expansion and protein-lipid interactions.

Main Results:

  • Cholera toxin binding caused a slight decrease in lipid layer density.
  • The toxin's A-subunit remained outside the lipid layer before enzymatic cleavage.
  • Monolayer expansion was consistent with geometrical constraints from toxin-GM(1) binding.

Conclusions:

  • Cholera toxin binding alters lipid monolayer structure, potentially aiding membrane translocation.
  • Changes in lipid packing may be a key mechanism for bacterial toxin entry.

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