A new cell-permeable fluorescent probe for Zn2+
A new cell-permeable fluorescent probe for Zn2+
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DOI：
10.1021/ja000868p
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发表时间：
2000-06-14
影响因子：
15
通讯作者：
Tsien, RY
中科院分区：
文献类型：
--
作者：
Walkup, GK;Burdette, SC;Tsien, RY
锌是一种重要的辅助因子，对许多细胞功能至关重要。1其独特的化学性质2及其在基因表达，3凋亡，4酶调节，5和神经传递6，7过程中的核心作用的组合表明，Zn 2+可能是细胞代谢中的主要调节离子。8，9虽然Zn 2+在真核生物中含量丰富，并且大多数是紧密结合的，但可螯合的Zn 2+池已经在活细胞中成像，其浓度范围从未分化的哺乳动物细胞中的亚nM到海马神经突触囊泡中的0.3 mM。11目前，最广泛应用的细胞锌探针是8-氨基喹啉的芳基磺酰胺，如6-甲氧基-（8-对甲苯磺酰胺基）喹啉（TSQ）、12锌喹4、13和TFLZn 11（TSQ类似物）。可螯合的和游离的Zn 2+之间的区别是有问题的，因为这些喹啉基染料可以形成混合的络合物，感测已经部分配位的Zn 2+。最近的研究已经澄清了一些细节，关于水溶液中的锌+结合平衡的这种染料，提高其作为定量探针的价值。14喹啉探针需要紫外线激发（λ 350 nm），然而，这可能对细胞造成损害，并且具有相对暗淡的荧光，量子产率为λ 0.1，消光系数为λ 10× 103 M-1 cm-1。15
Zinc is an essential cofactor, critical for numerous cellular functions. 1 The combination of its unique chemical properties2 and its central role in processes including gene expression, 3 apoptosis, 4 enzyme regulation, 5 and neurotransmission6, 7 suggests that Zn2+ may be a major regulatory ion in the metabolism of cells. 8, 9 Although Zn2+ is abundant in eukaryotes and most is tightly bound, pools of chelatable Zn2+ have been imaged in living cells with concentrations ranging from sub-nM in undifferentiated mammalian cells10 to∼ 0.3 mM in hippocampal nerve synaptic vesicles. 11 Currently, the most widely applied probes for cellular zinc are aryl sulfonamides of 8-aminoquinoline such as 6-methoxy-(8-p-toluenesulfonamido) quinoline (TSQ), 12 Zinquin4, 13 and TFLZn11 (TSQ analogues). The distinction between chelatable and free Zn2+ is problematic due to the fact that these quinolinebased dyes can form mixed complexes, sensing Zn2+ that is already partially coordinated. Recent studies have clarified some of the details regarding the aqueous Zn2+-binding equilibria of such dyes, enhancing their value as quantitative probes. 14 Quinoline probes require ultraviolet excitation (∼ 350 nm), however, which can be damaging to cells, and have relatively dim fluorescence with quantum yields≈ 0.1 and extinction coefficients≈ 10× 103 M-1 cm-1. 15