molecular details of the divalent-cation-driven stabilization of
the outer membranes in Gram-negative bacteria. We examine
the effects that take place as a result of calcium removal leading
to the destabilization of the bilayer asymmetry and mixing of
LPS molecules between the inner and outer leaflets. The results
highlight the importance of salt bridges formed by divalent
cations such as Ca2+ and Mg2+ with negatively charged sugars in
LPS core oligosaccharide. These interactions appear to be
crucial to the structural integrity of the outer membrane, with
the disruptive nature of the electrostatic repulsive forces
between adjacent LPS molecules revealed when charge
screening is removed.