Interaction of bovine immunoglobulin gamma 2 (IgG2) with staphylococcal protein A: evidence for IgG2a and IgG2b sub-subclasses in the bovine.
The reactivity of bovine IgG with protein A is confusing with respect to which of the bovine IgG class and subclasses are reactive. We have, therefore, re-examined the interaction of bovine immunoglobulins with protein A. The results presented in this paper indicated that at pH 8.0 protein A binds only immunoglobulin of the IgG2 subclass. The bound IgG2 can be readily recovered from an immobilized protein A column at pH 5.0. Furthermore, the antigenic IgG2 eluted demonstrated two charged species which could readily be separated by ion-exchange chromatography. These results indicate that IgG2 in the bovine exists in two sub-subclasses, IgG2a and IgG2b. The two sub-subclasses of IgG2 could be rapidly isolated with a good yield in two-steps namely protein A affinity chromatography followed by ion exchange chromatography.
D000818:Animals; D000907:Antibodies, Bacterial / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D002003:Brucella abortus / Q000276:immunology; D002417:Cattle / Q000276:immunology*; D002848:Chromatography, DEAE-Cellulose; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D011485:Protein Binding; D013205:Staphylococcal Protein A / Q000276:immunology*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A