PARTICIPATION OF GLYCOSYLATION SITES IN THE BINDING OF STAPHYLOCOCCUS-AUREUS TO LAMININ

1. Microbial pathogenicity is in many instances associated with the ab ility to adhere to host surfaces or to extracellular matrix components . 2. Laminin is a major glycoprotein of basement membranes which can p romote specific bacterial adhesion. Staphylococcus aureus is a pathoge nic bacterium which presents a laminin receptor of about 50-kDa molecu lar mass (Lopes JD, Reis M & Brentani RR (1985). Science, 229: 275-277 ). 3. Adhesion inhibition assays of [iodine-125]-labeled bacteria to l aminin demonstrate that the receptor binding site is contained in the pepsin-derived (P1) laminin fragment. 4. Cell adhesion to laminin is u naffected by periodate oxidation of sugars on the surface of bacteria or by removal of divalent cations by ethylenediaminetetraacetic acid ( EDTA). In contrast, bacterial adhesion is reduced when laminin is degl ycosylated with N-glycosidase F or when bacteria are submitted to cont rolled trypsin digestion. 5. Laminin binding to the S. aureus 50-kDa b and in immunoblotting assays has confirmed all of these results obtain ed in cell adhesion experiments.