Design and Synthesis of Highly Sensitive and Selective Fluorescein-Derived Magnesium Fluorescent Probes and Application to Intracellular 3D Mg2+ Imaging
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- 作者：Hirokazu Komatsu ; Naoko Iwasawa ; Daniel Citterio ; Yoshio Suzuki ; Takeshi Kubota ; Kentaro Tokuno ; Yoshiichiro Kitamura ; Kotaro Oka ; and Koji Suzuki
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：December 22, 2004
- 年：2004
- 卷：126
- 期：50
- 页码：16353 - 16360
- 全文大小：354K
- 年卷期：v.126,no.50(December 22, 2004)
- ISSN：1520-5126
文摘
The role of intracellular magnesium ions is of high interest in the fields of pharmacology andcellular biology. To accomplish the dynamic and three-dimensional imaging of intracellular Mg2+, there isa strong desire for the development of optimized Mg2+ fluorescent probes. In this paper we describe thedesign, synthesis, and cellular application of the three novel Mg2+ fluorescent probes KMG-101, -103, and-104. The compounds of this series feature a charged 
-diketone as a binding site specific for Mg2+ anda fluorescein residue as the fluorophore that can be excited with an Ar+ laser such as is widely used inconfocal scanning microscopy. This molecular design leads to an intensive off-on-type fluorescent responsetoward Mg2+ ions. The two fluorescent probes KMG-103 and -104 showed suitable dissociation constants(Kd,Mg2+ = 2 mM) and nearly a 10-fold fluorescence enhancement over the intracellular magnesium ionconcentration range (0.1-6 mM), allowing high-contrast, sensitive, and selective Mg2+ measurements. Forintracellular applications, the membrane-permeable probe KMG-104AM was synthesized and successfullyincorporated into PC12 cells. Upon application of the mitochondria uncoupler FCCP to the probe-incorporatedcells, the resulting increase in the free magnesium ion concentration could be followed over time. By usinga confocal microscope, the intracellular 3D magnesium ion concentration distributions were satisfactorilyobserved.
-diketone as a binding site specific for Mg2+ anda fluorescein residue as the fluorophore that can be excited with an Ar+ laser such as is widely used inconfocal scanning microscopy. This molecular design leads to an intensive off-on-type fluorescent responsetoward Mg2+ ions. The two fluorescent probes KMG-103 and -104 showed suitable dissociation constants(Kd,Mg2+ = 2 mM) and nearly a 10-fold fluorescence enhancement over the intracellular magnesium ionconcentration range (0.1-6 mM), allowing high-contrast, sensitive, and selective Mg2+ measurements. Forintracellular applications, the membrane-permeable probe KMG-104AM was synthesized and successfullyincorporated into PC12 cells. Upon application of the mitochondria uncoupler FCCP to the probe-incorporatedcells, the resulting increase in the free magnesium ion concentration could be followed over time. By usinga confocal microscope, the intracellular 3D magnesium ion concentration distributions were satisfactorilyobserved.