Cell surfaces are glycosylated in various ways with high heterogeneity, which usually leads to ambiguous conclusions about glycan-involved biological functions. Here, we describe a two-step chemoenzymatic approach for N-glycan-subtype-selective editing on the surface of living cells that consists of a first ‘delete’ step to remove heterogeneous N-glycoforms of a certain subclass and a second ‘insert’ step to assemble a well-defined N-glycan back onto the pretreated glyco-sites. Such glyco-edited cells, carrying more homogeneous oligosaccharide structures, could enable precise understanding of carbohydrate-mediated functions. In particular, N-glycan-subtype-selective remodeling and imaging with different monosaccharide motifs at the non-reducing end were successfully achieved. Using a combination of the expression system of the Lec4 CHO cell line and this two-step glycan-editing approach, opioid receptor delta 1 (OPRD1) was investigated to correlate its glycostructures with the biological functions of receptor dimerization, agonist-induced signaling and internalization.

细胞表面以各种方式被糖基化，具有高度异质性，这通常会导致关于涉及聚糖的生物学功能的结论不明确。在这里，我们描述了一种在活细胞表面上进行N-聚糖亚型选择性编辑的两步化学酶法，该方法包括第一个“删除”步骤以去除某个亚类的异质N-糖型和第二个“插入”步骤步骤，将定义明确的N-聚糖组装回到预处理的糖位上。这种带有更均一的寡糖结构的糖基修饰细胞可以精确地了解碳水化合物介导的功能。特别是N成功地实现了在非还原末端具有不同单糖基序的β-聚糖亚型选择性重塑和成像。结合使用Lec4 CHO细胞系的表达系统和这种分两步进行的聚糖编辑方法，研究了阿片受体δ1（OPRD1）使其糖结构与受体二聚化，激动剂诱导的信号传导和内在化的生物学功能相关。 。