title: Noninvasive imaging of sialyltransferase activity in living cells by chemoselective recognition.
abstract: To elucidate the biological and pathological functions of sialyltransferases (STs), intracellular ST activity evaluation is necessary. Focusing on the lack of noninvasive methods for obtaining the dynamic activity information, this work designs a sensing platform for in situ FRET imaging of intracellular ST activity and tracing of sialylation process. The system uses tetramethylrhodamine isothiocyanate labeled asialofetuin (TRITC-AF) as a ST substrate and fluorescein isothiocyanate labeled 3-aminophenylboronic acid (FITC-APBA) as the chemoselective recognition probe of sialylation product, both of which are encapsulated in a liposome vesicle for cellular delivery. The recognition of FITC-APBA to sialylated TRITC-AF leads to the FRET signal that is analyzed by FRET efficiency images. This strategy has been used to evaluate the correlation of ST activity with malignancy and cell surface sialylation, and the sialylation inhibition activity of inhibitors. This work provides a powerful noninvasive tool for glycan biosynthesis mechanism research, cancer diagnostics and drug development.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ding
authors.affiliation: Department of Pharmaceutical &Biological Chemistry, UCL School of Pharmacy, University College London, London WC1N 1AX, UK.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P.R. China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D001212:Asialoglycoproteins / Q000737:chemistry / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D057075:Enzyme Assays; D060748:Fetuins / Q000737:chemistry / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D012235:Rhodamines / Q000737:chemistry / Q000378:metabolism; D012799:Sialyltransferases / Q000378:metabolism*; D059010:Single-Cell Analysis; D013194:Staining and Labeling
chemical_list: D001212:Asialoglycoproteins; D014408:Biomarkers, Tumor; D060748:Fetuins; D005456:Fluorescent Dyes; D012235:Rhodamines; C017029:asialofetuin; C009434:tetramethylrhodamine isothiocyanate; D012799:Sialyltransferases; D016650:Fluorescein-5-isothiocyanate