Immunochemical studies of partially hydrolyzed lipopolysaccharide from Fusobacterium nucleatum Fev1

Fusobacterium nucleatum Fev1 lipopolysaccharide was split by hydrolysis with 1% acetic acid into acid-soluble polysaccharide and lipid A. Gel filtration of the polysaccharide on Bio-Gel P-60 gave a high-molecular-weight fraction eluted with the void volume, and a fraction eluted at 2.4 x Vo. The high-molecular-weight fraction contained L-glycero-D-manno-heptose in relatively large amounts, glucose, glucosamine, an unknown amino compound and small amounts of (or no) D-glycero-D-manno-heptose. Phosphorus and 3-deoxy-D-manno-octulosonic acid were not detected. The other fraction contained L- and D-glycero-D-manno-heptose, glucose, glucosamine, 3-deoxy-d-manno-octulosonic acid and phosphorus. Further fractionation experiments and serological investigations indicated that the high-molecular-weight fraction carried the O-antigenic side chains, whereas the material eluted from Bio-Gel P-60 at 2.4 x Vo represented the core oligosaccharide.