Agglutination activity is expressed in µg/mL and is determined from serial dilutions of a 1 mg/mL solution using phosphate buffered saline, pH 6.8, containing, for each lectin, calcium, magnesium, and manganese at different concentrations. This activity is the lowest concentration to agglutinate a 2% suspension of appropriate erythrocytes after 1 hr incubation at 25 °C.
BS-I has a major affinity for terminal a-D-galactosyl residues with a secondary affinity for terminal N-acetyl-a-D-galactosaminyl residues.
BS-I is a tetrameric lectin consisting of two types of subunits designated A and B. There are five BS-I isolectins with different subunit composition: BSI-B4, BSI-AB3, BSI-A2B2, BSI-A3B and BSI-A4. BSI-B4 is blood group B specific and has an exclusive affinity for terminal α-D-galactosyl residues, whereas BSI-A4 has blood group A specificity and has a major affinity for terminal N-acetyl-α-D-galactosaminyl residues.
Contains sodium citrate