Shigella sonnei lipopolysaccharide core region (S. sonnei LPS core) (S. sonnei LPS core)

The Shigella sonnei lipopolysaccharide (LPS) core region is a complex oligosaccharide structure situated between the lipid A anchor and the O-specific polysaccharide chain in the outer membrane of the Gram-negative bacterium Shigella sonnei (Kasper et al., 2000, Journal of Biological Chemistry). This region is essential for maintaining the structural integrity and permeability barrier of the bacterial cell wall, protecting the pathogen from detergents, bile salts, and certain antibiotics within the host's gastrointestinal tract (Nikaido, 2003, Microbiology and Molecular Biology Reviews). In Shigella sonnei, the core is typically of the R1 type, which is relatively conserved compared to the highly variable O-antigen (Muller-Loennies et al., 2002, Journal of Biological Chemistry). As a therapeutic target, the LPS core is the primary binding site for cationic antimicrobial peptides and polymyxin antibiotics, such as Polymyxin B and Colistin, which interact with the negatively charged phosphate groups to disrupt the outer membrane (Velkov et al., 2013, Journal of Medicinal Chemistry). Additionally, the core region is a critical component in the development of conjugate vaccines, where the S. sonnei O-antigen is linked to carrier proteins; the core provides the necessary linkage and can contribute to the overall immunogenicity of the vaccine construct (Cohen et al., 2021, The Lancet Infectious Diseases). Understanding the core's structure is vital for overcoming antibiotic resistance and developing broad-spectrum glycoconjugate vaccines against shigellosis.

Other names

Shigella sonnei core oligosaccharideS. sonnei LPS coreShigella sonnei R-LPSShigella sonnei R1-type core

Polymyxins bind to the lipid A-core oligosaccharide complex via electrostatic interactions with negative phosphate groups, leading to displacement of divalent cations and subsequent disruption of the outer membrane (Velkov et al., 2013). In vaccine applications, the LPS core serves as a structural scaffold for O-antigen presentation, facilitating the induction of bactericidal antibodies that recognize the LPS complex (Cohen et al., 2021).