Enzyme‐Catalyzed Synthesis of a Hybrid N‐Linked Oligosaccharide using N‐Acetylglucosaminyltransferase I

The soluble catalytic domain of human N‐acetylglucosaminyltransferase I was purified from Escherichia coli and utilized in the enzyme‐catalyzed conversion of high mannose N‐linked oligosaccharide 1 into the rare hybrid oligosaccharide 2. Analysis of the reaction showed that the conversion of high mannose 1 into hybrid oligosaccharide 2 proceeded to 100% completion as assessed by MALDI‐TOF‐MS. Purification of the large polar oligosaccharide by gel filtration and silica gel chromatography afforded a 42% isolated yield of oligosaccharide 2. This enzyme‐catalyzed reaction can be utilized to produce rare hybrid oligosaccharides for biochemical and structural studies.