Purification and partial characterization of Fusobacterium necrophorum hemagglutinin

Hemagglutinin (HAin) of Fusobacterium necrophorum was separated from the bacterial cells by trypsinization-sonication, and purified by the gel filtration on Sephadex G-100 column. The final product obtained from gel filtration gave one precipitin line in the immunodiffusion gel and produced a single band in polyacrylamide gel electrophoresis. The molecular weight of the HAin was estimated to be about 19000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It was heat labile and comparatively rich in alanine, glutamine and histidine. Electron microscopy observation revealed that the HAin was a filamentous rod with 0.5-1.0 nm width or frequently showed a cluster form. The hemagglutinability was inhibited by addition of albumins but not by sugars and lipopolysaccharide. Anti HAin rabbit serum inhibited hemagglutination.