Binding of human clusterin by Staphylococcus epidermidis.
To hypothesise that Staphylococcus epidermidis may possess clusterin receptor(s), bacterial binding of human clusterin was determined. In a fluid phase, the binding was markedly influenced by culture medium and three out of 12 S. epidermidis strains grown on ISO-sensitest agar expressed clusterin-binding ability. S. epidermidis J9P, selected for further study, showed saturable binding of iodine-labelled clusterin, and the binding was only inhibited by unlabelled clusterin. The binding was sensitive to protease treatment. Scatchard plot indicated one single class of binding sites (K(d)=104.2 nM). None of the S. epidermidis strains bound immobilised clusterin. These data imply that ligand-receptor interaction exists between S. epidermidis and clusterin in fluid phase, but the domain(s) recognised by bacteria may have been occluded when clusterin was adsorbed on a surface.
Li
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Department of Medical Microbiology, Dermatology and Infection, Lund University, Sölvegatan 23, S-223 62 Lund, Sweden.
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D051152:Clusterin; D003169:Complement Inactivator Proteins / Q000378:metabolism*; D003470:Culture Media; D019286:Endopeptidase K / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D012995:Solubility; D013203:Staphylococcal Infections / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology
C495242:CLU protein, human; D051152:Clusterin; D003169:Complement Inactivator Proteins; D003470:Culture Media; D006023:Glycoproteins; D018832:Molecular Chaperones; D014357:Trypsin; D019286:Endopeptidase K