Preparative purification of soybean agglutinin by affinity chromatography and its immobilization for polysaccharide isolation

Optimized procedures for the affinity purification of soybean agglutinin (SBA) from soybean flour, and its further immobilization, were developed. Lectin purification on galactosyl-Sepharose yielded 44.5±3.5 mg of pure SBA/50 g of flour. To prepare SBA adsorbents, the lectin was immobilized onto 1-cyano-4-(dimethylamino)pyridinium tetrafluoroborate (CDAP) activated Sepharose with high yields (77%). Feasibility of the use of this improved SBA adsorbent for affinity purification of Streptococcus pneumoniae capsular polysaccharides from strain 14 (CPS-14) at laboratory scale was demonstrated. Using SBA-Sepharose adsorbent (7.0 mg lectin per ml), amounts of 6.3 mg of pure CPS-14 per cycle were produced, the adsorbent being reused up to four times without loss of capacity.