Wheat germ agglutinin (WGA) is affinity purified lectin that non-enzymatically binds to N-acetyl-D-glucosamine and sialic acid residues of glycoproteins and glycolipids. This lectin protects Triticum vulgaris from insects, yeast and bacteria. WGA consists of two subunits and has a molecular weight of 36,000. It is an acidic protein and has mitogenic activity toward lymphocytes. It agglutinates erythrocytes and most types of malignant cells. WGA, similar to insulin, enhances the rate of glucose oxidation in isolated fat cells. It inhibits C5a receptor interaction and is used for isolation and fractionation of insulin receptors.
Alkaline phosphatase (AP) is conjugated to Triticum vulgaris Lectin (WGA) to show the binding of WGA 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.