Bioorthogonal Conjugation Directed by a Sugar‐Sorting Pathway for Continual Tracking of Stressed Organelles. Issue 32 (4th July 2018)

• Record Type: Journal Article
• Authors: Xue, Zhongwei; Zhang, Enkang; Liu, Jian; Han, Jiahuai; Han, Shoufa
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 32(2018)
• Page Start: 10096
• Page End: 10101
• Publication Date: 2018-07-04
• Subjects: apoptosis -- bioorthogonal reactions -- cell death -- ratiometric fluorescence imaging -- stressed organelles; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201802972
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Selective and continuous tracking of dynamic organelles is crucial for modern biology. We herein report a ship‐in‐a‐bottle strategy for tagging lysosomes by a strain‐promoted azide–alkyne cycloaddition to couple a pH sensor (RC) with mannose‐6‐carboxylate (M6C) actively transported into lysosomes through cell sorting. In contrast to classical acidotropic sensors, which are prone to dissipate from lysosomes, M6C‐RC formed in situ is stably trapped in lysosomes without resort to lysosomal acidity and exhibits "always‐on" blue fluorescence to pinpoint lysosomes and red‐to‐blue fluorescence ratios indicative of the lysosomal pH value. These advantages enable tracking of stressed lysosomes, and necrosis to be differentiated from apoptosis on the basis of lysosomal pH changes. The cell‐sorting‐mediated bioorthogonal tagging strategy offers a new route to track stressed organelles with disrupted physiological organelle–probe affinity. Abstract : Like a ship in a bottle, an azide‐bearing rhodamine‐lactam/coumarin dyad (pH sensor, RC) underwent a structural change inside lysosomes through cycloaddition with a mannose‐carboxylate (M6C) actively transported into lysosomes through cell sorting, and was then trapped inside the cells (see scheme). Thus, stable lysosomal staining was possible during necrosis/apoptosis, and these cell‐death pathways could be differentiated on the basis of pH changes.