Protein-specific localization of a rhodamine-based calcium-sensor in living cells

Marcel Best, Isabel Porth, Sebastian Hauke, Felix Braun, Dirk-Peter Herten, Richard Wombacher

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)
184 Downloads (Pure)


A small synthetic calcium sensor that can be site-specifically coupled to proteins in living cells by utilizing the bio-orthogonal HaloTag labeling strategy is presented. We synthesized an iodo-derivatized BAPTA chelator with a tetramethyl rhodamine fluorophore that allows further modification by Sonogashira cross-coupling. The presented calcium sensitive dye shows a 200-fold increase in fluorescence upon calcium binding. The derivatization with an aliphatic linker bearing a terminal haloalkane-function by Sonogashira cross-coupling allows the localization of the calcium sensor to Halo fusion proteins which we successfully demonstrate in in vitro and in vivo experiments. The herein reported highly sensitive tetramethyl rhodamine based calcium indicator, which can be selectively localized to proteins, is a powerful tool to determine changes in calcium levels inside living cells with spatiotemporal resolution.
Original languageEnglish
Pages (from-to)5606-5611
JournalOrganic and Biomolecular Chemistry
Publication statusPublished - 7 Apr 2016


Dive into the research topics of 'Protein-specific localization of a rhodamine-based calcium-sensor in living cells'. Together they form a unique fingerprint.

Cite this