Bacterial lipopolysaccharide (LPS) (LPS)

Bacterial lipopolysaccharide (LPS), also known as endotoxin, is a fundamental structural component of the outer membrane of Gram-negative bacteria, such as Escherichia coli (Raetz & Whitfield, 2002, Annu. Rev. Biochem.). It consists of three distinct regions: a hydrophobic Lipid A domain, a core oligosaccharide, and a distal O-antigen polysaccharide. The E. coli J5 strain is a well-characterized 'rough' mutant that lacks the O-antigen, exposing the highly conserved core LPS structure, which has historically made it a primary target for developing cross-reactive antisera and monoclonal antibodies (Ziegler et al., 1982, N. Engl. J. Med.). LPS is a potent inducer of the innate immune response, acting as the primary ligand for the Toll-like receptor 4 (TLR4)/MD-2 complex on myeloid cells (Park & Lee, 2013, Exp. Mol. Med.). While this recognition is vital for host defense, the systemic release of LPS during severe infections can trigger an uncontrolled 'cytokine storm,' leading to sepsis, multi-organ failure, and septic shock. Therapeutic interventions targeting LPS include the use of polymyxin antibiotics, which bind and neutralize the Lipid A moiety, and experimental strategies such as enzymatic detoxification by alkaline phosphatase or sequestration by specialized antibodies (Opal, 2010, Antibiotics).

Other names

EndotoxinLipid ARough lipopolysaccharideJ5 LPSPyrogenLipoglycan

Direct binding and neutralization of the Lipid A moiety to prevent interaction with the TLR4/MD-2 receptor complex; disruption of the bacterial outer membrane via displacement of divalent cations.