Fibronectin-binding proteins of a human oral spirochete Treponema denticola.

Major polypeptides from a human oral spirochete Treponema denticola ATCC 33520 were examined to demonstrate their ability to bind to human plasma fibronectin by immunoblot analysis. Of three main polypeptides separated on sodium dodecyl sulfate polyacrylamide gels 53,000-daltons (53-kDa) and 72-kDa surface antigenic proteins and a 38-kDa axial flagellar protein showed the ability to bind to fibronectin, suggesting that fibronectin on host cells can mediate cytoadherence of T. denticola by its binding to the surface proteins or the exposed 38-kDa axial flagellar protein.