EVIDENCE THAT THE HEPARIN-BINDING CONSENSUS SEQUENCE OF VITRONECTIN IS RECOGNIZED BY STAPHYLOCOCCUS-AUREUS

Binding of heparin-binding form of vitronectin to Staphylococcus aureu s was inhibited completely by heparin or by the same form of vitronect in. The binding was inhibited only to about 50% by the non-heparin-bin ding form of vitronectin, indicating an apparent involvement of the he parin-binding properties in the interaction between vitronectin and S. aureus. This was supported by experiments in which a synthetic peptid e (Ala(347)-Arg(361), comprising heparin-binding consensus sequences) was found to partly inhibit bacterial adherence to immobilized vitrone ctin. A bacterial cell surface protein could bind to the quinquedecape ptide, but not to the highly charged peptides consisting entirely of a rginine or lysine, immobilized on microtiter plates and the binding co uld be competitively inhibited by an excess of soluble peptide. Direct binding of radiolabeled peptide to bacterial cells was also demonstra ted, which was rapid, saturable, and pH-dependent. Furtherly a bacteri al surface protein having molecular mass of 60 kDa was isolated by aff inity chromatography on a quinquedecapeptide-HiTrap-NHS column. Our da ta suggest that the heparin-binding properties of vitronectin play a r ole in bacterial recognition.