A NEW MONOCLONAL ANTIBODY RECOGNIZING THE FULL-LENGTH INTRACELLULAR HUMAN A1,4-GALACTOSYLTRANSFERASE (GB3/CD77 SYNTHASE) AS WELL AS ITS SOLUBLE FORM IN THE BLOOD SERUM

摘要

Human a1,4-galactosyltransferase (Gb3/CD77 synthase), encoded by the A4GALT gene, catalyzes the transfer of galactose residue to lactosylceramide and paragloboside, creating globotriaosylceramide (Gb3, CD77, P~k antigen) and P1, which belong to the globo and neolacto glycosphingolipid series, respectively. Both P~k and P1 antigens contain the Gal-a(1,4)-Gal terminal structure and belong to the P1PK histo-blood group system. We found previously that the point mutation c.631C>G in the A4GALT gene causes a change of 211 amino acid from glutamine to glutamic acid (p.Q211E) [1]. The variant enzyme shows a broader acceptor specificity and in addition to P~k and P1 it catalyzes the synthesis of rare antigens NOR1 and NOR2, both of which terminate with a Gal-a(1,4)-GalNAc unit [2]. The aim of this study was to a obtain monoclonal antibody against an active recombinant catalytic domain of human a1,4-galactosyltransferase.