Generation of novel chimeric LacdiNAcS by gene fusion of a-lactalbumin and b1,4-galactosyltransferase 1

• Published in: Glycoconjugate journal 2009-07, Vol.26 (5), p.567-575
• Main Author: Do, Su-Il
• Format: Article
• Language: English
• ISSN: 0282-0080; 1573-4986
• DOI: 10.1007/s10719-008-9208-7

Novel chimeric lacdiNAc (GalNAc(b1-4)GlcNAc) synthase (c-LacdiNAcS) was generated by gene fusion of a-lactalbumin (a-LA) and b1,4-galactosyltransferase 1 (b1,4-GalT1). c-LacdiNAcS was expressed in Lec8 Chinese hamster ovary (Lec8 CHO) cells and exhibited N-acetylgalactosaminyltransferase (GalNAcT) activity in the absence of exogenous a-LA as well as other glycosyltransferase activities including lactose synthase (LacS), and b1,4-GalT. These glycosyltransferase activities of c-LacdiNAcS were compared to those activities induced in LacS system under the co-presence of bovine b1,4-GalT1 and a-LA, indicating that each domain of a-LA and b1,4-GalT1 on c-LacdiNAcS is not only folding correctly, but also interacting together. Furthermore, c-LacdiNAcS was found to be auto-lacdiNAcylated and can synthesize lacdiNAc structures on cellular glycoproteins, demonstrating that GalNAcT activity of c-LacdiNAcS is functional in Lec8 CHO cells.