Binding of human clusterin by Staphylococcus epidermidis

To hypothesise that Staphylococcus epidermidis may possess clusterin recept or(s), bacterial binding of human clusterin was determined. In a fluid phas e, the binding was markedly influenced by culture medium and three out of 1 2 S. epidermidis strains grown on ISO-sensitest agar expressed clusterin-bi nding ability. S. epidermidis J9P, selected for further study, showed satur able binding of iodine-labelled clusterin, and the binding was only inhibit ed by unlabelled clusterin. The binding was sensitive to protease treatment . Scatchard plot indicated one single class of binding sites (K-d = 104.2 n M). None of the S. epidermidis strains bound immobilised clusterin. These d ata imply that ligand-receptor interaction exists between S. epidermidis an d clusterin in fluid phase, but the domain(s) recognised by bacteria may ha ve been occluded when clusterin was adsorbed on a surface. (C) 2001 Federat ion of European Microbiological Societies. Published by Elsevier Science B. V. All rights reserved.