Core fucosylation, the attachment of an α-1,6-linked-fucose to the N-glycan core pentasaccharide, is an abundant protein modification that plays critical roles in various biological processes such as cell signaling, B cell development, antibody-dependent cellular cytotoxicity, and oncogenesis. However, the tools currently used to detect core fucosylation suffer from poor specificity, exhibiting cross-reactivity against all types of fucosylation. Herein we report the development of a new chemoenzymatic strategy for the rapid and selective detection of core fucosylated glycans. This approach employs a galactosyltransferase enzyme identified fromCaenorhabditis elegansthat specifically transfers an azido-appended galactose residue onto core fucose via a β-1,4 glycosidic linkage. We demonstrate that the approach exhibits superior specificity toward core fucose on a variety of complex N-glycans. The method enables detection of core fucosylated glycoproteins from complex cell lysates, as well as on live cell surfaces, and it can be integrated into a diagnostic platform to profile protein-specific core fucosylation levels. This chemoenzymatic labeling approach offers a new strategy for the identification of disease biomarkers and will allow researchers to further characterize the fundamental role of this important glycan in normal and disease physiology.

中文翻译：

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活细胞中核心岩藻糖基化的化学酶标记、检测和分析


核心岩藻糖基化是 α-1,6-连接岩藻糖与 N-糖核心五糖的结合，是一种丰富的蛋白质修饰，在各种生物过程中起着关键作用，如细胞信号传导、B 细胞发育、抗体依赖性细胞毒性和肿瘤发生。然而，目前用于检测核心岩藻糖基化的工具特异性较差，与所有类型的岩藻糖基化都表现出交叉反应性。在此，我们报道了一种新的化学酶策略的开发，用于快速和选择性地检测核心岩藻糖基化聚糖。这种方法采用从秀丽隐杆线虫中鉴定出的半乳糖基转移酶，该酶通过 β-1,4 糖苷键特异性地将叠氮基附加的半乳糖残基转移到核心岩藻糖上。我们证明该方法对各种复杂 N-糖上的核心岩藻糖表现出优异的特异性。该方法能够检测来自复杂细胞裂解物以及活细胞表面的核心岩藻糖基化糖蛋白，并且可以集成到诊断平台中，以分析蛋白质特异性核心岩藻糖基化水平。这种化学酶标记方法为鉴定疾病生物标志物提供了一种新策略，并将使研究人员能够进一步表征这种重要聚糖在正常和疾病生理学中的基本作用。