Isolation of Heavy and Light Chains of Immunoglobulin from the Surfaces of Lymphoid Cells

Abstract

Discussion and Summary The experimental results indicate that lactoperoxidase-catalyzed iodination of viable lymphoid cells is limited to the plasma membrane. Radiolabeled molecules from the cell surfaces of myeloma, lymphoma and normal spleen cells can be specifically precipitated with anti-Ig sera. Reduction and alkylation of these precipitates yield H and L chains. Gamma chain is present on P3K cells and µ chain on Daudi cells, as expected. Mµ chain was the predominant H chain found on spleen cells, consistent with recent experiments of others using lymphocytes (5, 10, 13, 16). Ig on the surface was not adsorbed to the plasma membrane and therefore presumably was synthesized by the cells. These findings provide evidence that Ig molecules on the plasma membrane, whether antigen-specific receptors or molecules destined for secretion, can be isolated and studied by conventional methods of immunochemistry and biochemistry.