title: Isolation and characterization of a receptor for type 1 fimbriae of Escherichia coli from guinea pig erythrocytes.
abstract: The adhesion of Escherichia coli to eukaryotic cells is mediated by proteinaceous surface appendages called fimbriae and complementary receptors on host cells. Although type 1 fimbriae, which contain a D-mannose-reactive lectin, have been well studied little is known about the binding mechanism of isolated fimbriae to individual cell receptors. This report describes the isolation and purification of a guinea pig erythrocyte receptor for type 1 fimbriae. Erythrocyte membranes were dissolved in 0.5% Triton X-100 and the receptor isolated and purified by affinity chromatography using type 1 fimbriae immobilized on Sepharose. The 65-kDa receptor, which inhibits the agglutination of guinea pig erythrocytes by type 1 fimbriated E. coli, has a pI of 8.5-8.7, and binds concanavalin A and type 1 fimbriae in a dose-dependent and saturable manner. The fimbrial binding activity of the receptor was reduced when treated with sodium metaperiodate, endoglycosidase H, trypsin, and V8 protease, suggesting the isolated receptor is a glycoprotein with N-linked carbohydrate units. Isolated type 1 fimbriae inhibited the binding of fimbriated E. coli to purified receptor in a dose- and time-related fashion. The calculated binding affinity was 6 X 10(6) M-1, a value consistent with the low binding affinity expected from previous studies of the agglutination of guinea pig erythrocytes by isolated type 1 fimbriae.
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000032:analysis*; D004926:Escherichia coli / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006168:Guinea Pigs; D006384:Hemagglutination / Q000187:drug effects; D006596:Hexosaminidases / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis; D011971:Receptors, Immunologic / Q000302:isolation & purification* / Q000378:metabolism; D012995:Solubility
chemical_list: D008565:Membrane Proteins; D011971:Receptors, Immunologic; C037872:pili, bacterial receptor; D006596:Hexosaminidases