A novel a-Gal resin was chemo-enzymatically synthesized for the efficient adsorption of anti-a-Gal antibodies in human serum for xenotransplantation. To covalently conjugate a hexanoate linker with lactose and N-acetylglucosamine, both acceptor sugars were acetylated and brominated. Then, alpha- and beta-galactoses were sequentially added to the linker-containing saccharides at their non-reducing ends by using recombinant alpha-(1,3)- and beta-(1,4)-galactosyltransferases from E. coli. Finally, the synthesized a-Gal derivatives were immobilized on HiCore, a core-shell type resin, that was functionalized with amino groups on the shell region, as a packing material on-column. Using this method we were able to demonstrate that the a-Gal HiCore resin had a reduced level of non-specific protein adsorption compared with the commercially available polystyrene supports, TentaGel, and agarose-based supports, when Lectin BS-I was used as the model binding protein. Furthermore, the alpha-Gal HiCore resin was more efficient at eliminating anti-a-Gal IgGs from the total human IgGs through immunoadsorption than the other two alpha-Gal resins, alpha-Gal TentaGel and a-Gal agarose. The a-Gal HiCore resin developed in this study can be utilized in a wide range of applications including ex vivo immunoadsorption and as a quantitative assay of anti-Gal antibody in human sera. (c) KSBB.
