| Abstract: | Four silica-based adsorbents were prepared from covalent attachment of four carbohydrates: i. e. maltose, cellobiose, N-acetyl-D -glucosamine and p-aminophenyl-β-D -glucopyranoside, respectively. These adsorbents posses either terminal D -glucose or N-acetyl-D -glucosamine as the ligand on their surfaces with a ligand density ranging from 20 to 29·2 μmol g?1. The binding of the glucose-specific lectin, concanavalin A (Con A), to the immobilized ligand on the silica surface depended on the configuration of the immobilized glucose and the linkage of the glucose to the support. Con A showed strong affinity for maltose-immobilized silica, which contains terminal α-D -glucose, and p-aminophenyl-β-D-glucopyranoside-immobilized silica. On the other hand, Con A showed no affinity for cellobiose-immobilized silica, which contains terminal β-D -glucose groups, and N-acetyl-D -glucosamine-immobilized silica. The binding constants for the interactions between Con A and immobilized ligands were determined. The columns packed with the resultant affinity adsorbents were then adopted for the purification of Con A from Jack bean meal. As the diluted NaCl extract of Jack bean meal was applied to the column packed with maltose-immobilized silica, a 13·2-fold purification was achieved by stepwise-elution. |
