A single high-affinity binding site for adenine and related compounds was identified in the lima bean lectin (LBL) component III tetramer. This site is identical with the high affinity site for 2,6-toludinyl-naphthalenesulfonate described previously (Roberts, D. D., and Goldstein, I. J. (1982) J. Biol. Chem. 257, 11274-11277). [14C]Adenine was bound with high affinity (Kd = 1.2 +/- 0.1 X 10(-5)...