Dolichos biflorus agglutinin (DBA) is isolated from horse gram and purified by affinity chromatography. DBA is a glycoprotein with a molecular weight of about 111,000 and consists of 4 subunits of equal size. This lectin has an isoelectric point between pH 4.6 and pH 5.5. It has a carbohydrate specificity toward α-N-acetylgalactosamine and elutes with the sugar GalNAc.
DBA has been used as a general marker of developing renal collecting ducts, which can then be used to establish secretion status in blood group A individuals by hemagglutination inhibition and for detecting blood typing. DBA is over thousand times more active in agglutinating blood group A1 cells versus A2 cells, and is used to distinguish these blood types in routine serology applications, and has potential applications in examining tumors which affect the levels of blood group substances.
Reconstitute with sterile buffer. Calcium, manganese, magnesium, and zinc ions are required for binding.
Alkaline phosphatase (AP) is conjugated to Dolichos biflorus Lectin (DBA) to show the binding of DBA in many applications including Western blotting and ELISA. Alkaline phosphatase is a large protein (140 kDa) that catalyzes the hydrolysis of phosphate groups from a substrate resulting in a colored or fluorescent product. The optimal enzymatic activity of this protein is between pH 8 and 10, and its reaction rate remains linear, improving sensitivity over time.