title: Streptococcal M6 protein binds to fucose-containing glycoproteins on cultured human epithelial cells.
abstract: M6 protein of Streptococcus pyogenes binds directly to HEp-2 cell surfaces and helps to mediate bacterial adhesion. Two epithelial cell receptors for M protein were identified as 97- and 205-kDa glycoproteins. Purified recombinant M6 protein (rM6) showed a dose-dependent and saturable binding to isolated HEp-2 membranes in an enzyme immunoassay. The HEp-2 cell receptors were selectively denatured by pretreatment of isolated membranes at 80 degrees C or with chymotrypsin; binding activity for rM6 was reduced 83 and 80%, respectively. Pretreatment of the HEp-2 membranes with neuraminidase-N-glycosidase, neuraminidase-O-glycosidase, alpha-L-fucosidase, or Ulex lectin caused 33, 42, 73, and 80% reduction of rM6 binding, respectively. Quantitative analysis of HEp-2 cells pretreated with alpha-L-fucosidase showed that the 97- and 205-kDa glycoproteins lost 70 and 62% of their abilities to bind M6 protein and that 33% of the HEp-2 cell's ability to bind whole streptococci was also lost. These results indicated that binding of M6 protein to HEp-2 cell surfaces is highly selective for certain fucose-containing oligosaccharides on these glycoproteins.
authors.affiliation: Department of Microbiology, School of Medicine, State University of New York at Buffalo 14214.
authors.forename: J R
authors.initials: JR
authors.lastname: Wang
authors.forename: M W
authors.initials: MW
authors.lastname: Stinson
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins; D002478:Cells, Cultured; D004848:Epithelium / Q000378:metabolism; D005643:Fucose / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D011817:Rabbits; D013297:Streptococcus pyogenes / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; C014689:streptococcal M protein; D005643:Fucose