State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, People's Republic of China.
Anal Chem. 2020 May 19;92(10):7232-7239. doi: 10.1021/acs.analchem.0c00810. Epub 2020 Apr 28.
Lipid rafts, highly ordered cell membrane domains mainly composed of cholesterol, sphingolipids, and protein receptors, serve as important functional platforms for regulation of lipid/protein interactions. The major predicament in lipid raft study is the lack of direct and robust visualization tools for in situ tracking raft components. To solve this issue, we herein report a proximity enzymatic glyco-remodeling strategy for direct and highly efficient lipid raft labeling and imaging on live cells. Through cofunctionalization of raft-specific recognition motif and glycan-remodeling enzyme on gold nanoparticles, the fabricated nanoprobe can be specifically guided to the raft domains to perform catalytic remodeling on neighboring glycans. Taking advantage of the abundant glycoconjugates enriched in lipid rafts, this elaborate design achieves the translation of one raft-recognition event to multiple raft-confined labeling operations, thus, significantly increasing the labeling efficiency and imaging sensitivity. The direct covalent labeling also enables in situ and long-term tracking of raft components in live cells. The method possesses broad applicability and potential expansibility, thus, will greatly facilitate the investigations on the complex composition, organization, and dynamics of lipid rafts.
脂质筏是高度有序的细胞膜区域，主要由胆固醇、鞘脂和蛋白质受体组成，作为调节脂质/蛋白质相互作用的重要功能平台。脂质筏研究的主要难题是缺乏用于原位跟踪筏成分的直接和强大的可视化工具。为了解决这个问题，我们在此报告了一种邻近酶糖基重塑策略，用于在活细胞上进行直接和高效的脂质筏标记和成像。通过在金纳米粒子上共功能化筏特异性识别基序和糖基重塑酶，制备的纳米探针可以被特异性引导到筏域，在邻近的糖上进行催化重塑。利用富含脂质筏的丰富糖缀合物，这种精心设计实现了一个筏识别事件到多个筏限制标记操作的转化，从而显著提高了标记效率和成像灵敏度。直接共价标记还能够在活细胞中进行原位和长期跟踪筏成分。该方法具有广泛的适用性和潜在的可扩展性，因此将极大地促进对脂质筏的复杂组成、组织和动力学的研究。
