THE STRUCTURE OF LIPOOLIGOSACCHARIDE PRODUCED BY NEISSERIA-GONORRHOEAE, STRAIN-15253, ISOLATED FROM A PATIENT WITH DISSEMINATED INFECTION -EVIDENCE FOR A NEW GLYCOSYLATION PATHWAY OF THE GONOCOCCAL LIPOOLIGOSACCHARIDE

We studied the structure of the lipooligosaccharide (EOS) that is prod uced by Neisseria gonorrhoeae, strain 15253. This strain, recovered fr om a patient with disseminated infection, produces predominately a sin gle LOS component, and its oligosaccharide (OS) structure is different from those of previously studied LOSs. Definition of this OS structur e provides additional information on the LOS biosynthesis. We determin ed that the 15253 OS has an unusual structure: 2 lactosyl residues at its nonreducing ends shown below, [GRAPHICS] where KDO is 2-keto-3-deo xy-mannooctulosonic acid and Hep is heptose. Comparison of this OS str ucture with those determined previously indicates the presence of a ne w glycosylation pathway for gonococcal OS biosynthesis: elongation of a GlcNAc-linked heptose, in contrast to elongation of the other heptos e by sequential addition of glycoses which results in the antigenic si milarity with human glycolipids. The current study provides not only a dditional structural information on LOS expressed during different cli nical states of infection but also evidence for the diversity of gonoc occal LOS biosynthesis. This evidence may be helpful in understanding the pathogenesis involving gonococcal LOS.