Extraction and Purification of Lectin from Soybean Seeds (Glycine max)

In this study, the effectiveness of the ion exchange column packed with anionic resin DEAE-Sephadex®-A-50 in purifying lectin isolated by conventional saline buffer method was investigated. After the lectin extraction, the purification efficacy of ion exchange cationic and anionic resins was compared. The purified lectin was freeze-dried to a solid state to characterize its physiochemical properties. The characterization included the presence and content of protein, sulfur, and carbohydrate, hemagglutination test, gel electrophoresis for molecular weight determination, and metal photometry for sodium content determination. The physiochemical characterization was carried out by Fourier-transfer infrared spectroscopy and X-ray diffraction studies. The test results were compared with the standard sample of soybean lectin. The purified lectin was amorphous, basic in nature, tetramer, galactose binding/N-acetylgalactosamine molecule in its sodium salt form, with a molecular weight of 120 kiloDaltons. Based on the results, the anionic resin DEAE-Sephadex®-A-50 can effectively purify lectin isolated from soybean seeds.