BINDING-PROPERTIES OF PROTEIN-A AND PROTEIN-G FOR HUMAN IGE

We studied the binding of protein A and protein G to human monoclonal and polyclonal IgE. An ELISA was used to measure human IgE. Protein A- Sepharose did not bind to monoclonal IgE, but bound to 12-14% of serum polyclonal IgE and to -3% of the polyclonal IgE purified from the ser um. No difference in binding to protein A was found between IgE from a n allergic patient and that from a non-allergic subject. Protein G bou nd to neither polyclonal IgE nor monoclonal IgE. Thus, protein G is be tter than protein A with respect to separation of IgE from IgG.