Bausteine von Oligosacchariden, CII. Synthese von modifizierten Derivaten der 2-Acetamido-2-desoxy-D-galactose zur Untersuchung der Substratspezifität der Core-1-β3-Gal-Transferase und der Core-3-β3-GlcNAc-Transferase der Biosynthese vonO-Glycoproteinen

Abstract

Building Units of Oligosaccharides, CII. – Synthesis of Modified Derivatives of 2-Acetamido-2-deoxy-D-galactose for the Examination of Substrate Specificities of Core 1-β3-Gal-Transferase and Core 3-β3-GlcNAc-Transferase Involved in the Biosynthesis of O-Glycoproteins The 2-, 3-, 4-, and 6-deoxy derivatives of benzyl 2-acetamido-2-deoxy-α-D-galactopyranoside (7) have been synthesized to test substrate specificities of glycosyltransferases involved in the biosynthesis of O-glycoproteins. The core 1-β3-Gal-transferase dose not require the 6-hydroxyl group for activity in contrast to the glycosylation reaction of the core 3-β3-GlcNAc-transferase which requires the 6-hydroxyl group. Compounds with reactive groups substituting the 6-hydroxyl group such as the diazirine 45 could be suitable for photolabeling of the former enzyme. A column for affinity chromatography with the 6-deoxy derivative as the ligand could be useful to separate the two enzymes during purification.