Microbial cell membrane phospholipids and lipopolysaccharides (LPS/PL)

Microbial cell membrane phospholipids and lipopolysaccharides (LPS) are fundamental structural elements of the bacterial cell envelope that ensure cellular stability and serve as a protective barrier against external threats [NIH/NCBI, 2022]. Lipopolysaccharides, primarily found in the outer membrane of Gram-negative bacteria, consist of a hydrophobic Lipid A anchor, a core oligosaccharide, and an O-antigen polysaccharide [NIH/NCBI, 2022]. Lipid A is specifically recognized by the host immune system as a potent endotoxin, triggering inflammatory cascades via Toll-like receptor 4 [NIH/NCBI, 2022]. Phospholipids form the lipid bilayer in both Gram-positive and Gram-negative bacteria, maintaining the electrochemical gradients essential for ATP synthesis and nutrient transport [Nature Reviews Microbiology, 2021]. These molecules are the primary targets for several "last-resort" antibiotics, such as polymyxins and daptomycin [StatPearls, 2023]. Polymyxins act by binding to the negatively charged Lipid A of LPS, displacing stabilizing divalent cations and causing membrane leakage [StatPearls, 2023]. Daptomycin targets phosphatidylglycerol in Gram-positive membranes, leading to calcium-dependent insertion and rapid depolarization [StatPearls, 2023]. While highly effective against multidrug-resistant pathogens, drugs targeting these components often carry significant risks of nephrotoxicity and neurotoxicity due to potential interactions with host cell membranes [StatPearls, 2023]. The release of large amounts of LPS during treatment can also lead to systemic inflammatory responses like the Jarisch-Herxheimer reaction [NIH/NCBI, 2022]. Understanding these targets is crucial for developing new strategies to combat antibiotic resistance in clinical settings [Nature Reviews Microbiology, 2021].

Other names

Bacterial membrane lipidsEndotoxinLipid ABacterial cell envelope componentsOuter membrane lipopolysaccharides

Disruption of membrane integrity through binding to Lipid A or phospholipids, leading to displacement of divalent cations, pore formation, and membrane depolarization [StatPearls, 2023].