Specific binding of bone sialoprotein to Staphylococcus aureus isolated from patients with osteomyelitis

Abstract

In contrast, binding was not inhibited by a bacterial lysate from an osteopontin A gtll lysogen, nor by N-linked oligosaccharide isolated from bone sialoprotein or by proteoglycan from rat chondrosarcoma containing clustered 0-linked oligosaccharides of the same structure as those of bone sialoprotein. These results indicate that the major staphylococcal-binding site resides in the bone sialoprotein core protein and not in the carbohydrate side chains. No inhibition of bone sialoprotein binding could be detected for whole human serum or purified plasma proteins such as fibronectin, fibrinogen and IgG. Likewise, staphylococcal protein A or rat collagen type I did not inhibit the binding of bone sialoprotein. The latter results indicate that the binding site for bone sialoprotein on staphylococcal cells was not any of the hitherto described staphylococcal cell-surface proteins. Binding data indicated an average of 1000 bone-sialoprotein-binding sites/bacterial cell.

Purification of a bone sialoprotein‐binding protein from Staphylococcus aureus

“…We conclude that this protein is novel and distinct from the ECM-binding proteins previously isolated from staphylococcal cells, based on differences in relative molecular masses, and the inability of other ECM components, such as fibronectin, fibrinogen, collagen or laminin to inhibit the binding of BSP by staphylococcal cells (RydCn et al, 1989).…”

“…Binding of "'I-BSP to staphylococcal cells, and detection of inhibitory activity was quantified as described previously (RydCn et al, 1989). In brief, staphylococcal cells were grown for 10-12 hours in trypticase soy broth, harvested cells were washed twice in ice-cold phosphate-buffered saline (NaCUP,; 0.1 3 M NaC1, 10 mM sodium phosphate, pH 7.4) and resuspended in binding-buffer (137 mM NaC1, 5 mM KCI, 0.7 mM MgS0,,1.2 mM CaCl,, 10 mM Hepes, pH 7.4, 0.1% ovalbumin) to a concentration of 10'" bacteria/ ml.…”

“…aureus, strain 0 2 4 was originally isolated from a patient suffering from acute osteomyelitis (RydCn et al, 1989). S. aureus, strain E514 was isolated from a patient suffering from acute endocarditis (Rydtn et al, 1989).…”

“…A high proportion of isolates from cases of septic arthritis and osteomyelitis bound BSP, whereas isolates from staphylococcal infections at other body locations usually did not (RydCn et al, 1987). Staphylococcal cells bind BSP in a specific reaction, having a dissociation constant around 10nM (RydCn et al, 1989). Furthermore, the putative staphylococcal BSP-binding protein recognized a binding site in the BSP core protein located at the amino terminus and distinct from the Arg-Gly-Asp binding site for mammalian cells (RydCn, et al, 1989).…”

“…Staphylococcal cells bind BSP in a specific reaction, having a dissociation constant around 10nM (RydCn et al, 1989). Furthermore, the putative staphylococcal BSP-binding protein recognized a binding site in the BSP core protein located at the amino terminus and distinct from the Arg-Gly-Asp binding site for mammalian cells (RydCn, et al, 1989).…”