CELL SURFACE ANTIGENS AND CELL SURFACE PROTEINS: Problems and Approaches for Protein Chemistry

Abstract

Abstract: Cell-cell interactions and cell-ligand interactions depend upon the physico-chemical interactions of receptors, the specificity of these receptors, and their linkage to metabolic events within the cell. Analyses of these phenomena at the molecular level are providing challenges for the protein chemist that require a greatly expanded view and closer interaction with the cell biologist than in previous structural studies in immunology and enzymology. This paper reviews studies in our laboratory that provide the biological framework for our characterization of cell surface receptors at the molecular level. These studies include: 1) experiments on the mobility and redistribution of cell surface receptors and the modulation of receptor and cell movements by lectins such as concanavalin A and various drugs which suggest that these receptors may have a common anchorage system under the plasma membrane; 2) analysis of the initial events in the mitogenic stimulation of lymphocytes by Con A which suggests that the same colchicine-binding protein system may be involved in mediating the modulation of receptor mobility and mitogenic activation; and 3) direct analysis of the chemical structure of surface molecules such as β 2 -microglobulin which suggests that it may be possible to classify receptors into groups of molecules with common evolutionary origins.