Open AccessPurification of a bone sialoprotein‐binding protein from Staphylococcus aureus
Author(s) -
YACOUB Alia,
LINDAHL Per,
RUBIN Kristofer,
WENDEL Mikael,
HEINEGÅRD Dick,
RYDÉN Cecilia
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb18940.x
Subject(s) - bone sialoprotein , staphylococcus aureus , sepharose , chemistry , elution , protein a , microbiology and biotechnology , biochemistry , chromatography , biology , bacteria , enzyme , alkaline phosphatase , osteocalcin , antibody , immunology , genetics
Bone sialoprotein (BSP) is selectively bound by Staphylococcus aureus cells isolated from patients suffering from infections of bone and joint tissues [Rydén C., Maxe, I., Franzén, A., Ljungh, Å., Heinegård, D. & Rubin, K. (1987) Lancet II , 515]. We now report on the purification of a cell‐wall protein from Staphylococcus aureus , strain O24, that possesses affinity for bone sialoprotein. Staphylococcal cell‐wall components with capacity to inhibit binding of 125 I‐labeled BSP to staphylococcal cells were solubilized with LiCl (1.0 M, pH 5.0). Preparative SDS/PAGE and protein‐overlay experiments revealed that inhibitory activity present in LiCl extracts resided in a fraction of polypeptides with M r 75000–110000. Staphylococcal proteins solubilized with LiCl were chromatographed on a Mono‐Q anion‐exchange column. Inhibitory activity was eluted at 0.6–0.8 M NaCl and could be further purified by affinity chromatography on BSP‐Sepharose. Elution of the affinity matrix with 0.1 M glycine, pH 3.0, specifically eluted inhibitory activity. Analysis by SDS/PAGE revealed a single M r 97000 polypeptide in the eluate. The purified M r 97000 protein bound BSP in protein‐overlay experiments. LiCl extracts from S. aureus , strain E514 or Staphylococcus epidermidis , strain 7686, both lacking the capacity to bind BSP did not contain the M r 97000 protein. Our data demonstrate the presence of a S. aureus , cell‐surface BSP‐binding protein. This protein could be involved in bacterial tropism in osteomyelitis.