N-Glycans are asparagine attaching oligosaccharides that are important in many biological functions such as protein conformation, antigenicity and recognition. Among the abundant types of N-glycans, poly-N-actyllactosamine (poly-LacNAc) containing complex type N-glycans are found on the surfaces of immune cells and cancer cells that can regulate immune checkpoint and are associated with tumor progression and metastasis. However, acquiring these pure and well-defined N-glycans from nature sources are often tedious and laborious. Hence, we are developing a chemoenzymatic synthesis that combines chemical and enzymatic approaches to obtain poly-LacNAc bearing N-glycans. This approach would allow selective installations of LacNAc repeat units at distinct glycan arms and enable further biological studies. In this work, we present the strategy for the synthesis of asymmetric N-glycans with LacNAc repeat units at the different arms.
