Proton-dependent zinc release from intracellular ligands.
Proton-dependent zinc release from intracellular ligands.
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DOI：
10.1111/jnc.12712
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发表时间：
2014-07
影响因子：
4.7
通讯作者：
Kiedrowski L
中科院分区：
文献类型：
--
作者：
Kiedrowski L
在培养的大脑皮层和海马神经元中，当细胞内pH从6.6降至6.1时，尚不清楚的细胞内存储将微摩尔数量的锌离子释放到胞浆中。线粒体、酸性细胞器和/或细胞内配体可以释放这种锌离子。尽管暴露于原载体FCCP阻止了线粒体和酸性细胞器与锌离子的重新加载，但FCCP并未损害细胞内存储重复释放锌离子的能力。因此，锌离子释放库不是线粒体或酸性细胞器，而是细胞内的锌离子配体。为了测试哪些配体可能参与其中，研究了半胱氨酸、谷胱甘肽、组氨酸、天冬氨酸、谷氨酸、甘氨酸和肌肽的配合物在酸诱导下释放锌的速率；使用比率锌敏感的荧光探针FuraZin-1在体外监测了[锌]。肌肽对锌离子没有螯合作用，但对铜离子有螯合作用；其余的配基对锌离子有螯合作用，酸化后将其释放到介质中。而当pH从6.6降至6.1时，只有锌-半胱氨酸络合物加速了锌离子的释放。当组氨酸修饰剂二乙基焦碳酸酯在pH 7.2时，锌-半胱氨酸络合物也释放出锌离子。由于胞内锌-半胱氨酸复合体可以含有微摩尔数量的锌离子，这些复合体可能代表了酸诱导的细胞内锌离子释放的储备物。
In cultured cortical and hippocampal neurons when intracellular pH drops from 6.6 to 6.1, yet unclear intracellular stores release micromolar amounts of Zn2+ into the cytosol. Mitochondria, acidic organelles, and/or intracellular ligands could release this Zn2+. Although exposure to the protonophore FCCP precludes re-loading of the mitochondria and acidic organelles with Zn2+, FCCP failed to compromise the ability of the intracellular stores to repeatedly release Zn2+. Therefore, Zn2+-releasing stores were not mitochondria or acidic organelles but rather intracellular Zn2+ ligands. To test which ligands might be involved, the rate of acid-induced Zn2+ release from complexes with cysteine, glutathione, histidine, aspartate, glutamate, glycine, and carnosine was investigated; [Zn2+] was monitored in vitro using the ratiometric Zn2+-sensitive fluorescent probe FuraZin-1. Carnosine failed to chelate Zn2+ but did chelate Cu2+; the remaining ligands chelated Zn2+ and upon acidification were releasing it into the medium. However, when pH was decreasing from 6.6 to 6.1, only zinc-cysteine complexes rapidly accelerated the rate of Zn2+ release. The zinc-cysteine complexes also released Zn2+ when a histidine-modifying agent, diethylpyrocarbonate, was applied at pH 7.2. Since the cytosolic zinc-cysteine complexes can contain micromolar amounts of Zn2+, these complexes may represent the stores responsible for an acid-induced intracellular Zn2+ release.
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DOI：
10.1016/s0006-291x(02)02017-x
发表时间：
2002-08-30
影响因子：
3.1
作者：
Haase, H;Beyersmann, D
通讯作者：
Beyersmann, D
影响因子：
4.8
作者：
Jiang, DM;Sullivan, PG;Weiss, JH
通讯作者：
Weiss, JH
影响因子：
4.8
作者：
Maranda, B;Brown, D;Marshansky, V
通讯作者：
Marshansky, V
影响因子：
4.8
作者：
Brown, AM;Kristal, BS;Cooper, AJL
通讯作者：
Cooper, AJL
影响因子：
3.3
作者：
BIFFO, S;GRILLO, M;MARGOLIS, FL
通讯作者：
MARGOLIS, FL