Development of immunoaffinity chromatographic method for isolating glycinin (11S) from soybean proteins.

A monoclonal antibody (Mab), 4B2, against soybean glycinin was prepared using the preliminary extracted natural glycinin as the immunogen in our previous study. Herein, we established a novel method for the purification of glycinin by Mab 4B2-based immunoaffinity chromatography. The characteristics of the purified glycinin were identified by SDS-PAGE, Western blot, and histamine release assay. Glycinin was successfully isolated from soybeans with a yield of 16.8% and a purity of 93.8%, which were significantly higher than those produced using other traditional procedures. The acidic polypeptides of the purified glycinin can be recognized by the Mab 4B2, but not the basic polypeptides. In addition, the histamine release ratio of the purified glycinin was similar to that of natural glycinin, which indicated that the purified glycinin maintained its biological activities. Further study revealed that the Mab/gel ratios ranging from 6.0 to 12.0 mg/mL were suitable for the isolation of glycinin using immunoaffi...