Membrane-permeable and -impermeable sensors of the Zinpyr family and their application to imaging of hippocampal zinc in vivo
Membrane-permeable and -impermeable sensors of the Zinpyr family and their application to imaging of hippocampal zinc in vivo
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DOI：
10.1016/j.chembiol.2004.09.013
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发表时间：
2004-12-01
影响因子：
--
通讯作者：
Lippard, SJ
中科院分区：
文献类型：
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作者：
Woodroofe, CC;Masalha, R;Lippard, SJ
荧光生物传感器的酯化是用于将探针捕获在细胞内的常见策略。 Zinpyr-1 (ZP1) 是一种基于荧光素的二价锌明亮荧光传感器，无需事先修饰即可渗透细胞。我们在此描述了在荧光素的 5 或 6 位上含有羧酸或乙酯官能团的 ZP1 传感器的合成和表征。电负性羧酸盐的存在通过降低负责荧光猝灭的苄基胺的 pK(a) 来降低探针的质子诱导背景荧光。带电物质 ZP1(6-CO2-) 是膜不可渗透的，而中性 ZP1(5/6-CO2Et) 的渗透性与母体传感器的渗透性相似。与 ZP1 相比，将 ZP1(6-CO2Et) 颅内微量输注到大鼠海马中，神经纤维中的囊泡锌染色减少，锌阳性损伤的神经元体和树突的轮廓非常清晰。
Esterification of fluorescent biosensors is a common strategy used to trap probes within the cell. Zinpyr-1 (ZP1) is a fluorescein-based bright fluorescent sensor for divalent zinc that is cell permeable without prior modification. We describe here the synthesis and characterization of ZP1 sensors containing a carboxylic acid or ethyl ester functionality at the 5 or 6 position of the fluorescein. The presence of an electronegative carboxylate decreases the proton-induced background fluorescence of the probe by lowering the pK(a) of the benzylic amines responsible for fluorescence quenching. The charged species ZP1(6-CO2-) is membrane-impermeant, whereas the permeability of the neutral ZP1(5/6-CO2Et) is similar to that of the parent sensor. Intracranial microinfusion of ZP1(6-CO2Et) into rat hippocampus produces reduced staining of vesicular zinc in neuropil and very clear delineation of zinc-positive injured neuronal somata and dendrites as compared with ZP1.