Journal of Glycobiology
Open Access

Efficient chemo-enzymatic synthesis of (sialylated) galacto-N-biose derivatives

Glycobiology World Congress

August 10-12, 2015 Philadelphia, USA

Lei Li

Posters-Accepted Abstracts: J Glycobiol

Abstract :

Disaccharide galacto-N-biose (GNB, Gal�²1-3GalNAc) is a common glycan structure in nature. GNB with an �±-configuration
at the reducing end linked to the serine or threonine residue in glycoproteins (Gal�²1â��3GalNAc�±Ser/Thr) is named
T-antigen and is one of the most common tumor-associated carbohydrate antigens (TATCs) found overexpressed on human
carcinoma cells including those of lung cancer, prostate cancer, breast cancer etc. On the other hand, GNB with a �²-configuration
at the reducing end (Gal�²1-3GalNAc�²) is an essential part of globo-series (e.g., Globo-H, Gb5, sialyl Gb5) and ganglio-series
(e.g., GA1, GM1, GD1, GT1, GP1, GQ1, etc) glycosphingolipids. In this study, Galacto-N-biose (GNB) derivatives were
efficiently synthesized from galactose derivatives via a one-pot two-enzyme system containing two promiscuous enzymes
from Bifidobacterium infantis: a galactokinase (BiGalK) and a D-galactosyl-�²1-3-N-acetyl-D-hexosamine phosphorylase
(BiGalHexNAcP). Mono-sialyl and di-sialyl galacto-N-biose derivatives were then prepared using a one-pot two-enzyme
system containing a CMP-sialic acid synthetase and �±2-3-sialyltransferase or �±2-6-sialyltransferase.