Lipopolysaccharide lipid A domain (Lipid A)

Lipid A is the highly conserved, hydrophobic anchor of lipopolysaccharide (LPS) found in the outer membrane of almost all Gram-negative bacteria (PMID: 12110610). It serves as the primary endotoxic component of LPS, recognized by the human innate immune system via the Toll-like receptor 4 (TLR4) and myeloid differentiation factor 2 (MD-2) complex (PMID: 19349967). Upon recognition, it triggers the release of pro-inflammatory cytokines, which is essential for clearing infections but can lead to life-threatening sepsis and septic shock if the response is systemic (StatPearls: Sepsis). In clinical medicine, Lipid A is a critical target for last-resort antibiotics like polymyxins, which bind to its phosphate groups to destabilize the bacterial cell wall (PMID: 23432315). Furthermore, research into Lipid A analogs has led to the development of vaccine adjuvants and potential treatments for endotoxemia (PubChem CID 11960511).

Other names

EndotoxinLPS lipid ALipid A moietyLipid A domain

Direct binding to the lipid A moiety to disrupt the bacterial outer membrane or to neutralize its ability to activate the TLR4/MD-2 complex (PMID: 23432315).