Peptide targeting of fluorescein-based sensors to discrete intracellular locales

• Main Authors: Radford, Robert John (Contributor), Chyan, Wen (Contributor), Lippard, Stephen J. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor)
• Format: Article
• Language: English
• Published: Royal Society of Chemistry, 2016-08-15T20:46:49Z.
• Subjects: Article
• Online Access: Get fulltext

 Fluorescein-based sensors are the most widely applied class of zinc probes but display adventitious localization in live cells. We present here a peptide-based localization strategy that affords precision in targeting of fluorescein-based zinc sensors. By appending the zinc-selective, reaction-based probe Zinpyr-1 diacetate (DA-ZP1) to the N-terminus of two different targeting peptides we achieve programmable localization and avoid unwanted sequestration within acidic vesicles. Furthermore, this approach can be generalized to other fluorescein-based sensors. When appended to a mitochondrial targeting peptide, the esterase-activated profluorophore 2',7'-dichlorofluorescein diacetate can be used effectively at concentrations four-times lower than previously reported for analogous, non-acetylated derivatives. These results demonstrate on-resin or in-solution esterification of fluorescein to be an effective strategy to facilitate peptide-based targeting in live cells.