The Purification Of Soybean Agglutinin And Its Agglomerate Ability Research

After the soybean agglutinin was extracted by affinity chromatography, theagglomernate capacity to red cell and binging ability to intestinal epidermis cell of Soybeanagglutinin (SBA) was evaluated with or without glycoside ligands addition. The aim of thistrial is to pursuit a suitable method to evaluate the anti-nutrition activity of SBA.In experiment 1, SBA was purified by affinity chromatography from the crude extractof soybean seed. The separation was performed on D-galactose-Epoxy-Sepharoseo 4Bcolumn (1.6×20cm). The elution was collected after eluted with 0.15mol/L NaCl at first,and then with 0.15 mol/L NaCl containing 0.1 mol/L a-D-galactose. The elute solution withOD₂₈₀＞0.1 was collected, dialyzed, and freeze-dried. The purity of obtained extract wasidentified by PAGE electrophoresis. The extract had the same band as the standard SBA, i.e., high purity.In experiment 2, the minimal SBA concentration which could agglomerate 50% redcell of 2% rabbit red cell suspension was 2.50-3.69μg/ml. There was no agglutinate abilityof SBA to avian red cell suspension shown. The FITC-SBA was used to test the bindingability of SBA to fresh rabbit and avian intestinal epidermis cell suspension. The resultindicated that there was similar capacity of SBA to binding both rabbit and avian epidermiscell. For rabbit epidermis cell, the SBA could bind to 30% tested cell.In experiment 3, the agglomerate ability to red cell and binding ability to intestinalepidermis cell of SBA were tested after the SBA was complexed with either of fiveglycoside ligands, i.e., a-D-galactose, D-galactosamine, chitin, isoproperyl-β-D-sulfogalactose (IPTG) and a-lactose. The result indicated that, except chitin, the other fourligands could decrease the agglomerate ability of SBA to rabbbit red cell suspension and itsbinding ability to both rabbit and avian intestinal epidermis cell. Among these ligands,a-D-galactose shown the most inhibitive effect.In summary, the whole result showed: First, high purity SBA could be obtained byaffinity chromatography. Secondly, SBA could agglomerate to rabbit red cell suspension but could not agglutinate avian red cell suspension. But there was similar capacity of SBAto binding both rabbit and avian epidermis cell. The last was expect chitin the other fourligands could all decrease the ability of SBA to avian red cell suspension and its ability ofbinding both rabbit and avian epidermis cell. A suitable method to evaluate theanti-nutrition activity of SBA can be found through adding some glycoside ligands.