noun, plural: lipopolysaccharides
A compound in which a lipid molecule is bound to a polysaccharide by a covalent bond.
Lipopolysaccharide is commonly found as major constituent of the cell walls of certain bacteria, particularly the gram-negative strains, whose function is to help stabilize the overall membrane structure and to protect it from certain chemicals.
It is highly immunogenic and stimulates the production of endogenous pyrogen interleukin-1 and tumour necrosis factor. It is a potent activator of macrophages.
Word origin: from Greek lípos, fat + polysaccharide.
See also: lipid a.