Fibronectin binding domain of P. gingivalis fimbriae

P. gingivalis fimbriae play an important role in attachment of bacteria to various salivary components as well as to host cells and matrix proteins including fibronectin. In the present study, we investigated the binding domain of P. gingivalis fimbriae to fibronectin using synthetic peptides. A series of 20 mer fimbrillin peptides were used. Binding of fibronectin to purified fimbriae and synthetic peptides was assayed using polyclonal fibronectin antibodies as well as iodinated fibronectin. Purified fimbriae and peptide 126-146 (RMAFTEIKVQMSAAYDNIYTF) showed high levels of binding to fibronectin, while peptide 318-337(HLNVQCTVAEWVLVGQNATW) showed low but statistically significant binding. Our results suggest V-Q-X-X-X-A or V-X-X-X A common domain/domains present in both peptides might be involved in protein-protein interaction between P. gingivalis fimbriae and fibronectin.