title: Interaction of type II IgG Fc-receptors from streptococci of serological group A with murine IgG.
abstract: A group A streptococcal strain demonstrated binding activities for 125I-murine IgG3 and 125I-human IgG. This 125I-murine IgG3 binding could be inhibited by unlabelled equine IgG but not by IgG from cattle, chickens and dogs, indicating binding properties of IgG Fc-receptors of type II. In contrast to binding sites of Streptococcus dysgalactiae (serogroup C) carrying type III IgG Fc-receptors, the binding sites of the group A streptococcus appeared to be antigenically different, extremely sensitive to trypsin and did not show any cross reactions with human albumin. The group A and group C streptococcal binding sites could be solubilized by lysozyme treatment of the bacteria and subsequently isolated by affinity chromatography on human IgG-Sepharose. Further analysis of the group A and group C streptococcal binding proteins by SDS-PAGE and Western blotting revealed numerous, almost identical protein bands with binding activities for 125I-murine IgG3.
authors.affiliation: Institut für Bakteriologie und Immunologie, Justus-Liebig-Universität, Giessen.
authors.forename: C
authors.initials: C
authors.lastname: Lämmler
authors.forename: R
authors.initials: R
authors.lastname: Sting
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D015153:Blotting, Western; D002417:Cattle; D002645:Chickens; D002846:Chromatography, Affinity; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D006736:Horses; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D051379:Mice; D011961:Receptors, Fc / Q000302:isolation & purification / Q000378:metabolism*; D013297:Streptococcus pyogenes / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D011961:Receptors, Fc