Comparison of Different α-Galactosidases Used in the B to O Blood Conversion

#alpha#-Galactosidase could hydrolyze the #alpha# galactose residues on the surface of human blood type B erythrocyte, resulting in the conversion of the B antigen to O antigen. The peptide sequences of #alpha# galactosidases from soybean, coffee bean and human were aligned and analyzed with software of Lasergene. For further study, the cDNA encoding #alpha# galactosidases of soybean and human were expressed in pichia pastoris, respectively. The recombinant #alpha# galactosidase from soybean was purified by cation exchange chromatography while that from human was precipitated with ammonium sulfate and fractionated by gel filtration. Subsequently, the biochemical properties of each enzyme were assayed. The efficiency of different #alpha# galactosidase to hydrolyze the #alpha# galactose residues from human blood B erythrocyte were also compared. All the results demonstrated that the recombinant #alpha# galactosidase from soybean was more competent for B to O blood conversion.