The Fc binding regions in protein A are not responsible for the polyclonal B cell activating property of protein A.
To test whether the polyclonal B cell activating property of protein A is due to its ability to bind to the Fc part of immunoglobulins, experiments were carried out with purified monomeric or dimeric Fc-binding fragments of protein A. Neither monomeric nor dimeric fragments induced polyclonal antibody synthesis in vitro, whereas intact protein A was a strong activator. It is concluded that the Fc binding part of protein A is not responsible for activation of polyclonal antibody synthesis.
D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D007141:Immunoglobulin Fc Fragments / Q000276:immunology*; D051379:Mice; D013205:Staphylococcal Protein A / Q000276:immunology*; D013347:Subcellular Fractions / Q000276:immunology
D007141:Immunoglobulin Fc Fragments; D013205:Staphylococcal Protein A