Hsu Tsui-Ling, Hanson Sarah R, Kishikawa Kuniyuki, Wang Sheng-Kai, Sawa Masaaki, Wong Chi-Huey
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Proc Natl Acad Sci U S A. 2007 Feb 20;104(8):2614-9. doi: 10.1073/pnas.0611307104. Epub 2007 Feb 12.
Developing tools for investigating the cellular activity of glycans will help to delineate the molecular basis for aberrant glycosylation in pathological processes such as cancer. Metabolic oligosaccharide engineering, which inserts sugar-reporting groups into cellular glycoconjugates, represents a powerful method for imaging the localization, trafficking, and dynamics of glycans and isolating them for glyco-proteomic analysis. Herein, we show that the alkyne-reporting group can be incorporated into cellular glycans. The alkyne group is a small, inert, bio-orthogonal handle that can be chemoselectively labeled by using the Cu(I) catalyzed [3 + 2] azide-alkyne cycloaddition, or click chemistry. Alkynyl sugar monomers, based on fucose (Fuc) and N-acetylmannosamine (ManNAc), were incorporated into fucosylated and sialylated glycans in several cancer cell lines, allowing for cell surface and intracellular visualization of glycoconjugates, as well as, observation of alkyne-bearing glycoproteins. Similarly to our previous results with an azido Fuc/alkynyl probe system, we demonstrated that click-activated fluorogenic probes are practical tools for efficiently and selectively labeling alkynyl-modified glycans. Because Fuc and sialic acid are terminal glycan residues with a notably increased presence in many tumors, we hope that our method will provide useful information about their roles in cancer and ultimately can be used for diagnostic and therapeutic purposes.
开发用于研究聚糖细胞活性的工具将有助于阐明诸如癌症等病理过程中异常糖基化的分子基础。代谢寡糖工程将糖报告基团插入细胞糖缀合物中，是一种用于成像聚糖的定位、运输和动力学以及分离它们进行糖蛋白质组分析的强大方法。在此，我们表明炔烃报告基团可以掺入细胞聚糖中。炔烃基团是一种小的、惰性的、生物正交手柄，可以通过使用铜（I）催化的[3 + 2]叠氮化物-炔烃环加成反应或点击化学进行化学选择性标记。基于岩藻糖（Fuc）和N-乙酰甘露糖胺（ManNAc）的炔基糖单体被掺入几种癌细胞系的岩藻糖基化和唾液酸化聚糖中，从而实现糖缀合物的细胞表面和细胞内可视化，以及观察含炔基的糖蛋白。与我们之前使用叠氮基Fuc/炔基探针系统的结果类似，我们证明点击激活的荧光探针是有效且选择性地标记炔基修饰聚糖的实用工具。由于Fuc和唾液酸是许多肿瘤中显著增加的末端聚糖残基，我们希望我们的方法将提供有关它们在癌症中的作用的有用信息，并最终可用于诊断和治疗目的。
