title: Reaction-based fluorescent sensor for investigating mobile Zn2+ in mitochondria of healthy versus cancerous prostate cells.
abstract: Chelatable, mobile forms of divalent zinc, Zn(II), play essential signaling roles in mammalian biology. A complex network of zinc import and transport proteins has evolved to control zinc concentration and distribution on a subcellular level. Understanding the action of mobile zinc requires tools that can detect changes in Zn(II) concentrations at discrete cellular locales. We present here a zinc-responsive, reaction-based, targetable probe based on the diacetyled form of Zinpyr-1. The compound, (6-amidoethyl)triphenylphosphonium Zinpyr-1 diacetate (DA-ZP1-TPP), is essentially nonfluorescent in the metal-free state; however, exposure to Zn(II) triggers metal-mediated hydrolysis of the acetyl groups to afford a large, rapid, and zinc-induced fluorescence response. DA-ZP1-TPP is insensitive to intracellular esterases over a 2-h period and is impervious to proton-induced turn-on. A TPP unit is appended for targeting mitochondria, as demonstrated by live cell fluorescence imaging studies. The practical utility of DA-ZP1-TPP is demonstrated by experiments revealing that, in contrast to healthy epithelial prostate cells, tumorigenic cells are unable to accumulate mobile zinc within their mitochondria.
authors: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139.
authors: Wen
authors: W
authors: Chyan
authors: Daniel Y
authors: DY
authors: Zhang
authors: Stephen J
authors: SJ
authors: Lippard
authors: Robert J
authors: RJ
authors: Radford
mesh_terms: D045744:Cell Line, Tumor; D011992:Endosomes / Q000378:metabolism; D005260:Female; D005452:Fluoresceins / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D008928:Mitochondria / Q000378:metabolism*; D011467:Prostate / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000378:metabolism*; D013997:Time Factors; D015032:Zinc / Q000378:metabolism*
chemical_list: C586943:DA-ZP1-TPP; D005452:Fluoresceins; D005456:Fluorescent Dyes; D015032:Zinc; C501987:zinpyr-1
keywords: fluorescence microscopy; prostate cancer; reaction-based probe; zinc biology