The isolation and properties of the dimeric subunit of Concanavalin A

Concanavalin A (Con A) was dissociated into dimeric and monomeric subunits by incubation at 37°C in acetate buffer of pH 3.8 containing 0.5% sodium dodecyl sulfate. The dimer was isolated in pure form by a density gradient ultracentrifugation method. Several properties of the dimer were determined including the formation of a precipitin with anti-Con A antibodies, the molecular weight, the lack of a binding site for glycogen, the lack of mitogenic activity for spleen lymphocytes, and the lack of inhibition by α-methyl D-glucoside. The latter findings differ from results reported by other investigators.