The murine lymphocyte receptor for IgE. II. Characterization of the multivalent nature of the B lymphocyte receptor for IgE

The murine B lymphocyte Fc epsilon R is functionally multivalent. Radiolabeled rat IgE, when bound to the B cell Fc epsilon R will co- isolate with the Fc epsilon R on a rat IgE affinity column; examination of the affinity column eluate by SDS-PAGE reveals the component previously identified as the Fc epsilon R as well as E and L chains from IgE. At low levels of Fc epsilon R saturation, up to 30% of the Fc epsilon R bound IgE becomes bound to IgE-Affi-Gel. By using a biotin- avidin system, the coprecipitation of non-haptenated IgE with haptenated IgE was examined and the results suggest (but do not prove) a divalent receptor.