title: Streptococcus agalactiae CAMP factor/protein B does not bind to human IgG.
abstract: CAMP factor is an extracellular cytolytic protein produced by Streptococcus agalactiae. CAMP factor has been reported to bind the Fc fragments of immunoglobulin G (IgG) and has therefore also been called protein B, in analogy to protein A of Staphylococcus aureus. We attempted to characterize the interaction of protein B with IgG in more detail. In contrast to protein A, CAMP factor does not inhibit the activation of complement by hemolysin antibodies bound to sheep red cell surfaces. IgG also failed to inhibit the co-hemolytic activity of CAMP factor, which is in disagreement with previous findings. After co-incubation, CAMP factor and IgG were cleanly separated by gel filtration, indicating that no binding had occurred.
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, ON, N2L 3G1 Canada.
authors.forename: Waseem
authors.initials: W
authors.lastname: El-Huneidi
authors.forename: Ryan
authors.initials: R
authors.lastname: Mui
authors.forename: Tian Hua
authors.initials: TH
authors.lastname: Zhang
authors.forename: Michael
authors.initials: M
authors.lastname: Palmer
mesh_terms: D001426:Bacterial Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D003165:Complement System Proteins / Q000276:immunology / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000276:immunology / Q000378:metabolism*; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D013292:Streptococcus agalactiae / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C039092:CAMP protein, Streptococcus; D006460:Hemolysin Proteins; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D003165:Complement System Proteins