1. A high-affinity fluorescent Zn2+ sensor improved by the suppression of pyridine-pyridone tautomerism and its application in living cells.
- Author
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Hagimori, Masayori, Temma, Takashi, Mizuyama, Naoko, Uto, Takuhiro, Yamaguchi, Yasuchika, Tominaga, Yoshinori, Mukai, Takahiro, and Saji, Hideo
- Subjects
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FLUORESCENCE , *ZINC ions , *METAL detectors , *PYRIDINE , *PYRIDONE , *TAUTOMERISM , *CELL physiology - Abstract
A high-affinity and low-molecular-weight fluorescent Zn 2+ sensor 1 based on a 2,2′-bipyridine scaffold, which functions as both the chelating moiety for Zn 2+ and the fluorophore, was developed and evaluated in biological applications. Controlling the occurrence of tautomerism of the chelating moiety for Zn 2+ by introducing an amino group at the 6-position of the pyridine ring dramatically increased the binding affinity toward Zn 2+ . Fluorescent sensor 1 exhibited a nanomolar-range dissociation constant ( K d = 2.2 nM), a large Stokes shift (140 nm), and an 8.6-fold turn-on response to Zn 2+ under physiological conditions. Fluorescence images revealed that fluorescent sensor 1 exhibits good properties with respect to aqueous solubility and cell permeability and can quantitatively detect the Zn 2+ levels in living cells. Furthermore, a 65 Zn 2+ radioactive zinc isotope uptake study revealed the real concentration of accumulated Zn 2+ at the detection limit. The novel fluorescent sensor 1 is a promising sensor for use in biological applications. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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