title: A 160-kilodalton epithelial cell surface glycoprotein recognized by plant lectins that inhibit the adherence of Actinomyces naeslundii.
abstract: The adherence of Actinomyces naeslundii to human epithelial (KB) cells is mediated by the interaction of a fimbrial lectin on this oral bacterium with epithelial cell receptors exposed by sialidase. The D-galactose- and N-acetyl-D-galactosamine-reactive plant lectins from peanut and from Bauhinia purpurea inhibit this interaction. This report describes the partial purification and characterization of a 160-kilodalton (kDa) cell surface glycoprotein which is the principal receptor for these lectins. Radioiodinated lectins detected a band of 160 kDa on sialidase-treated Western blots of epithelial cell extracts but did not detect bands on nontreated filters. However, wheat germ agglutinin was reactive with the 160-kDa band on filters that were not treated with sialidase, suggesting that this lectin recognizes the sialic acid residues of this molecule. The 160-kDa component was partially purified from n-octylglucoside extracts of the epithelial cells by wheat germ agglutinin affinity chromatography. This molecule was metabolically labeled with D-[14C]glucosamine and labeled at the cell surface by lactoperoxidase-catalyzed iodination or periodate oxidation followed by sodium borotritide reduction. Incubation of epithelial cells with sialidase before extraction resulted in the loss of the 160-kDa band and the appearance of a band at 200 kDa which was directly reactive with 125I-labeled peanut agglutinin. These results indicate that the 160-kDa glycoprotein on the surface of the epithelial cell serves as a receptor for the agglutinins from the peanut and B. purpurea and presumably the fimbrial lectin of actinomyces.
authors.forename: M J
authors.initials: MJ
authors.lastname: Brennan
authors.forename: J O
authors.initials: JO
authors.lastname: Cisar
authors.forename: A L
authors.initials: AL
authors.lastname: Sandberg
mesh_terms: D000190:Actinomyces / Q000378:metabolism*; D000268:Adhesiveness; D001667:Binding, Competitive; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003208:Concanavalin A / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism / Q000382:microbiology; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D019887:Peanut Agglutinin; D037121:Plant Lectins; D011971:Receptors, Immunologic / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000378:metabolism*; D014909:Wheat Germ Agglutinins
chemical_list: C039340:Bauhinia purpurea lectin; D037102:Lectins; D008565:Membrane Proteins; D019887:Peanut Agglutinin; D037121:Plant Lectins; D011971:Receptors, Immunologic; D012795:Sialoglycoproteins; D014909:Wheat Germ Agglutinins; C037872:pili, bacterial receptor; D003208:Concanavalin A