Association of receptors for mouse IgE with the plasma membrane of rat mast cells

Evidence was presented that mouse reaginic antibody can be absorbed with rat peritoneal mast cells. After disruption of whole peritoneal cells by ultrasonication in a hypotonic medium and subsequent differential centrifugation, the 20,000 x G supernatant blocked passive cutaneous anaphylaxis with mouse reaginic antibody. The same fraction from mast cell depleted preparation failed to block the passive cutaneous anaphylaxis reaction. Further purification was achieved by centrifugation on 35% Ficoll and by gel filtration through Sepharose 6B column. The blocking activity and membrane specific enzymes were eluted from Sepharose column in the void volume. Chromatography on DEAE cellulose separated the blocking fraction from the major bulk of the enzymatic membrane markers. Rechromatography of the active DEAE fraction on Sepharose 6B revealed a different elution pattern for the active component. Activity was recovered from the fractions between void volume and blue dextran (2000) elution thus indicating an apparent cleavage of cell membranes to a smaller size. Similar data were obtained with purified mast cells.