Partial purification of a bacterial lectinlike substance from Eikenella corrodens

Abstract

A bacterial lectinlike substance, which is considered to participate in the adherence of Eikenella corrodens to various host cells, was purified from E. corrodens cells. The substance was extracted in 1% Triton X-100 with sonication from the cell envelope of E. corrodens 1073 and partially purified by galactosamine affinity chromatography and gel filtration chromatography based on its hemagglutination (HA) activity. The lectinlike substance was purified about 256-fold as evaluated by its specific HA activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the partially purified lectinlike substance (PPL) produced a single protein band of large molecular weight when it was applied to the gel without the addition of beta-mercaptoethanol and heating. Chemical analysis showed that PPL contained 14.4 micrograms of hexose per 100 micrograms of protein and that it did not contain muramic acid, glucosamine, or 2,6-diaminopimelic acid, which are characteristic of peptidoglycans. The HA activity of PPL was inhibited by EDTA but restored by adding Ca2+. The HA activity was remarkably inhibited by sugars containing N-acetyl-D-galactosamine and D-galactose. These results indicate that the lectinlike substance on the E. corrodens cells is an essential factor for the adherence to host cells.