title: Glucose buffer is suitable for blood group conversion with α-N acetylgalactosaminidase and α-galactosidase.
abstract: BACKGROUND
  It is well known that the buffer plays a key role in the enzymatic reaction involved in blood group conversion. In previous study, we showed that a glycine buffer is suitable for A to O or B to O blood group conversion. In this study, we investigated the use of 5% glucose and other buffers for A to O or B to O blood group conversion by α-N-acetylgalactosaminidase or α-galactosidase.
  
  
  METHODS
  We compared the binding ability of α-N-acetylgalactosaminidase/α-galactosidase with red blood cells (RBC) in different reaction buffers, such as normal saline, phosphate-buffered saline (PBS), a disodium hydrogen phosphate-based buffer (PCS), and 5% commercial glucose solution. The doses of enzymes necessary for the A/B to O conversion in different reaction buffers were determined and compared. The enzymes' ability to bind to RBC was evaluated by western blotting, and routine blood typing and fluorescence activated cell sorting was used to evaluate B/A to O conversion efficiency.
  
  
  RESULTS
  The A to O conversion efficiency in glucose buffer was similar to that in glycine buffer with the same dose (>0.06 mg/mL pRBC). B to O conversion efficiency in glucose buffer was also similar to that in glycine buffer with the same dose (>0.005 mg/mL pRBC). Most enzymes could bind with RBC in glycine or glucose buffer, but few enzymes could bind with RBC in PBS, PCS, or normal saline.
  
  
  CONCLUSIONS
  These results indicate that 5% glucose solution provides a suitable condition for enzymolysis, especially for enzymes combining with RBC. Meanwhile, the conversion efficiency of A/B to O was similar in glucose buffer and glycine buffer. Moreover, 5% glucose solution has been used for years in venous transfusion, it is safe for humans and its cost is lower. Our results do, therefore, suggest that 5% glucose solution could become a novel suitable buffer for A/B to O blood group conversion.
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Hong-Wei
authors: HW
authors: Gao
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Su-Bo
authors: SB
authors: Li
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Guo-Qiang
authors: GQ
authors: Bao
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Xue
authors: X
authors: Zhang
authors: Department of Transfusion, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
authors: Hui
authors: H
authors: Li
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Ying-Li
authors: YL
authors: Wang
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Ying-Xia
authors: YX
authors: Tan
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Shou-Ping
authors: SP
authors: Ji
authors: Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, People's Republic of China.
authors: Feng
authors: F
authors: Gong
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D001441:Bacteroides fragilis / Q000201:enzymology; D001789:Blood Group Antigens / Q000737:chemistry*; D002021:Buffers; D004912:Erythrocytes / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006801:Humans; D000519:alpha-Galactosidase / Q000737:chemistry*; D048809:alpha-N-Acetylgalactosaminidase / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D001789:Blood Group Antigens; D002021:Buffers; D000519:alpha-Galactosidase; D048809:alpha-N-Acetylgalactosaminidase; D005947:Glucose