Changes in synthesis of concanavalin A binding proteins during nerve cell differentiation

Changes in the synthesis of concanavalin A binding proteins were analyzed at various times during nerve cell differentiation. Both mouse neuroblastoma cells as well as primary cells isolated from chicken dorsal root ganglia were used in these studies. Conditions were optimized for the biochemical differentiation of these cells, which were pulsed with radioactive methionine at several times during differentiation. Soluble extracts were prepared and optimum conditions for the isolation of those proteins which bind the lectin concanavalin A were determined. Incorporation of radioactivity into specific concanavalin A binding proteins was analyzed by two-dimensional gel electrophoresis and by computerized densitometry of the autoradiographs. Our results show that 10 concanavalin binding proteins are made only in differentiating neuroblastoma cells, and that twelve such proteins are made only in differentiating dorsal root ganglia cells. In addition, the synthesis of several other concanavalin A binding proteins increases dramatically during nerve cell differentiation. This class of proteins is now being further characterized by biochemical and immunological techniques.