Calorimetric study of rheumatoid factor binding to human IgG.
The binding of human IgM monoclonal rheumatoid factor (RF) to native human IgG was studied in a flow calorimeter. Thermal titration gave a enthalpy of binding of 5.5 X 10(4) J/mole site for the reaction, with 1 mole of RF binding to 2.5 moles of IgG; this corresponds to one RF subunit per IgG heavy chain. Similar experiments performed with heat-aggregated human IgG gave almost identical results. If the IgG molecule undergoes a conformational change upon heating, this is not such as to affect the enthalpic contribution of binding.
D000937:Antigen-Antibody Reactions; D001666:Binding Sites, Antibody; D002151:Calorimetry; D006358:Hot Temperature; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology; D012217:Rheumatoid Factor / Q000276:immunology*; D013816:Thermodynamics
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor