lipopolysaccharide

1. A compound or complex of lipid and carbohydrate. 2. The l. (endotoxin) released from the cell walls of Gram-negative organisms that produces septic shock.

* * *

li·po·poly·sac·cha·ride .lip-ō-.päl-i-'sak-ə-.rīd, .lī-pō- n a large molecule consisting of lipids and sugars joined by chemical bonds abbr. LPS

* * *

n.

a complex molecule containing both a lipid component and a polysaccharide component. Lipopolysaccharides are constituents of the cell walls of Gram-negative bacteria and are important in determining the antigenic properties of these bacteria.

* * *

lipo·poly·sac·cha·ride (lip″o-pol″e-sakґə-rīd) 1. a complex of lipid and polysaccharide. 2. a major component of the cell wall of gram-negative bacteria, a type of endotoxin and important group-specific antigen (O antigen). The lipopolysaccharide molecule consists of three parts: lipid A, a glycolipid responsible for the endotoxic activity, which is covalently linked to a heteropolysaccharide chain; the first part of the chain is the core polysaccharide, which is constant within related strains; and the second part of the chain is the O-specific chain, which is highly variable. Lipopolysaccharide from Escherichia coli is a commonly used B-cell mitogen (polyclonal activator) in laboratory immunology. Abbreviated LPS.