| Analysis Note | 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. |
| Biochem/physiol Actions | BS-I has a major affinity for terminal α-D-galactosyl residues with a secondary affinity for terminal N-acetyl-α-D-galactosaminyl residues.1 |
| Other Notes | 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. |
| Preparation Note | Prepared from peroxidase type VI using a modification of the method of O'Sullivan, et al. Repurified by affinity chromatography after conjugation. |
| Unit Definition | One unit will form 1 mg purpurogallin in 20 sec from pyrogallol at pH 6.0 at 20 °C. |
| Physical form | Contains sodium citrate buffer salts and calcium chloride |
