Bacterial outer membrane phospholipids

Bacterial outer membrane phospholipids are essential structural components of the Gram-negative bacterial cell envelope, primarily residing in the inner leaflet of the outer membrane. These lipids, which include phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin, are vital for maintaining the membrane's structural integrity and its function as a selective permeability barrier (Sohlenkamp & Geiger, 2016). They provide a specialized environment for the assembly and activity of outer membrane proteins, which are crucial for nutrient uptake and waste export. In the context of infectious diseases, these phospholipids serve as a primary target for cationic antimicrobial peptides and polymyxin antibiotics (Poirel et al., 2017). These drugs interact electrostatically with the negatively charged phospholipid headgroups, leading to the displacement of stabilizing divalent cations and subsequent membrane disruption (Trimble et al., 2016). This disruption results in the leakage of cytoplasmic contents and cell death, making these lipids a critical focus for treating multi-drug resistant Gram-negative infections. However, the therapeutic use of agents targeting these lipids is often constrained by potential toxicity to host tissues, particularly the kidneys and nervous system.

Other names

Bacterial membrane lipidsGram-negative outer membrane phospholipidsAnionic bacterial phospholipidsPhosphatidylethanolamine (PE)Phosphatidylglycerol (PG)Cardiolipin (CL)

Binding to anionic phospholipids and lipopolysaccharides leads to the displacement of divalent cations (Ca2+ and Mg2+), resulting in the disruption of the outer membrane integrity, increased permeability, and eventual cell death.