Synthesis of a Novel Fluorescent Ruthenium Complex with an Appended Ac?GlcNAc Moiety by Click Reaction.

ABSTRACT: The O-linked ?-N-acetylglucosamine (O-GlcNAc) modification is an abundant post-translational modification in eukaryotic cells, which plays a fundamental role in the activity of many cells and is associated with pathologies like type II diabetes, Alzheimer’s disease or some cancers. However, the precise connexion between O-GlcNAc-modified proteins and their function in cells is largely undefined for most cases. Confocal microscopy is a powerful and effective tool for in-cell elucidation of the function of biological molecules. Chemical labeling of non-ultraviolet or non-fluorescent carbohydrates with fluorescent tag is an essential step that makes intra-cellular microscopic inspection possible. Here we report a strategy based on the 1,3-dipolar cycloaddition, called click chemistry, between unnatural N-acetylglucosamine (GlcNAc) analogues Ac?GlcNAc (substituted with an azido group) and the corresponding fluorescent tag Ru(bpy)?(Phen-alkyne)Cl? (4) to synthesize the fluorescent dye Ru(bpy)?(Phen-Ac?GlcNAc)Cl? (5) under mild and neutral reaction conditions. Moreover, 5 showed good stability, desirable fluorescence characteristics, and exhibited rather low levels of cytotoxicity against sensitive MCF-7 cells. Additionally, we have achieved successful fluorescent imaging of 5 transported in living MCF-7 cells. Cell images displayed that proteins are potentially labelled with 5 in the cytoplasm.

SUBMITTER: Cheng Q 

PROVIDER: S-EPMC6100033 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature