B→O blood conversion

To maintain a constant supply of universal blood type, or group O red blood cells, has benefit in specialized transfusion condition. In this study, a-galactosidase cDNA was cloned from Catimor coffee bean grown in Hainan island, China, by the RT-PCR method. We have constructed a vector for a-galactosidase cDNA expression and transferred a-galactosidase cDNA into Pichia pastoris GS115 cells by elec-troporation. The recombinant a-galactosidase (r-a-GalE) was purified by cation ion exchange chromatography. After studying the biochemical characters of r-a-GalE, we have succeeded in converting human erythrocytes from group B to group O. The animal experiment showed that transfusion of enzymetically converted group O red blood cells (ECORBC) was perfectly safe.