Figure 4.

Model for calcium-induced fusion between fluid liposomes and gram-negative bacterial membrane.

Notes: Upon addition of calcium or other divalent cations, the LPS may be reoriented in such a conformation that their negatively-charged polysaccharide chains are aggregated and flat, close to the bacterial membrane. This would result in the exposition of their negatively-charged lipid A part. Calcium may then bridge fluid liposomes and bacteria causing aggregation, neutralizing the negative surface charges, dehydrating the headgroup of PE, and inducing local defect and fusion.

Abbreviations: LPS, lipopolysaccharides; PE, phosphatidylethanolamine.