Zinquin ethyl ester

Zinquin ethyl ester, a cell-permeable, quinolone-based fluorescent probe, is commonly used as a zinc indicator [1].  

Zinc is an important component of many enzymes, transcription factors, and other functional proteins, where it exerts specific actions over a wide range of physiological processes, such as growth, development, and functioning of the endocrine, immune, and nervous systems, and may contribute to the development of tumors [2].

In pig kidney LLC-PK1 cells treated with diethylamine NONOate (DEA-NO), 20 μM zinquin ethyl ester was used for detection of Zn²⁺ release [1]. In normal human prostate epithelial (NHPrE) cells, 25 μM zinquin ethyl ester was used to quantify the free labile zinc level, emitting four times stronger fluorescence than zinquin [2]. In wild-type murine aortic endothelial cells, zinquin ethyl ester at the concentration of 25 μM, was employed to track intranuclear Zn²⁺ release, triggered by NO which was derived from the inducible NO synthase activity [3].

References:

[1]. Karim M R, Petering D H. Detection of Zn²⁺ release in nitric oxide treated cells and proteome: dependence on fluorescent sensor and proteomic sulfhydryl groups. Metallomics, 2017, 9(4): 391-401.

[2]. Zhang J J, Wu M, Schoene N W, et al. Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells. American Journal of Physiology-Cell Physiology, 2009, 297(3): C632-C644.

[3]. Spahl D U, Berendji-Grün D, Suschek C V, et al. Regulation of zinc homeostasis by inducible NO synthase-derived NO: nuclear metallothionein translocation and intranuclear Zn²⁺ release. Proceedings of the National Academy of Sciences of the United States of America, 2003, 100(24): 13952-13957.