Styphnolobium japonicum agglutinin (SJA) is affinity purified from Japanese pagoda tree seeds. It consists of two subunits. The subunits can be separated into two subfractions, a D-galactose/N-acetyl-D-galactosamine specific lectin (B-SJA-I) and a D-mannose/D-glucose specific lectin (B-SJA-II). SJA has an isoelectric point between pH 4.9 and pH 5.6 and a carbohydrate specificity towards βGalNAc. This lectin elutes with the sugar GalNAc.
SJA agglutinates all blood group types but has greater affinity for A erythrocytes than of B types, than of O (-SA) types. Binding experiments of the lectin with frozen sections of human kidneys shows specific binding to the endothelia in specimens from blood groups B or AB, thus indicating a D-galactose/N-acetyl-D-galactosamine receptor specificity. SJA lacks mitogenic and immune-suppressive activity.
Styphnolobium japonicum Lectin (SJA) is labeled with tetramethylrhodamine isothiocyanate (TRITC) and has an appropriate number of fluorochromes bound to provide the optimum staining characteristics for this lectin. TRITC is a bright orange or red-fluorescent dye with excitation ideally suited to the 532-nm laser line. TRITC labeled SJA can be used for cellular imaging applications.