Blood group A and B glycosyltransferases synthesize A and B determinants on different acceptor polyglycosyl peptidesin vitro

Autor: Viitala, Juha
Zdroj: Glycoconjugate Journal; June 1985, Vol. 2 Issue: 2 p149-161, 13p
Abstrakt: The glycosylation of polyglycosyl chains from human erythrocytes by human plasma blood group A and B glycosyltransferases was studied in order to clarify why human blood group AB erythrocyte polyglycosyl peptides carry only either A or B determinants [Eur J Biochem (1981) 113:259–65]. The blood group A transferase was able to add radioactiveN-acetylgalactosamine from labeled UDP-N-acetylgalactosamine to B-type erythrocytes which had been treated with α-galactosidase in order to cleave the B determinant sugar from the erythrocytes. This suggests that the enzymes specified by theAandBgenes utilize the same acceptor molecules on erythrocyte membranes. Polyglycosyl peptides isolated from blood group B erythrocytes acted as acceptors for blood group A glycosyltransferase and the generation of hybrid structures containing both A and B determinants was demon-strated. When blood group O polyglycosyl peptides were used as acceptors in the simultaneous presence of both blood group A and B glycosyltransferases, however, the A and B determinant sugars were found in different polyglycosyl peptides. It is suggested that the enzyme-acceptor complex does not dissociate until the final number of determinants has been added.
Databáze: Supplemental Index
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