Metallothionein transfers zinc to mitochondrial aconitase through a direct interaction in mouse hearts
Metallothionein transfers zinc to mitochondrial aconitase through a direct interaction in mouse hearts
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DOI：
10.1016/j.bbrc.2005.04.170
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发表时间：
2005-07-08
影响因子：
3.1
通讯作者：
Kang, YJ
中科院分区：
文献类型：
--
作者：
Feng, W;Cai, J;Kang, YJ
先前的研究表明，在无细胞系统中，当环境变得氧化时，金属硫蛋白（MT）释放锌，并且如果存在锌结合蛋白，则释放的锌被转移到锌结合蛋白。然而，目前尚不清楚锌是否以及如何从MT转移到体内的其他蛋白质。本研究进行测试的假设，如果锌从MT转移到其他蛋白质在体内发生，转移将通过MT和一组特定的蛋白质之间的直接相互作用进行。从MT敲除小鼠获得的心脏提取物与Zn-65-MT或（ZnCl 2）-Zn-65孵育，并且通过蓝色非变性PAGE（BN-PAGE）或十二烷基硫酸钠-PAGE（SDS PAGE）分离接受Zn-65的蛋白，并通过放射自显影进行检测。从Zn-65-MT孵育的制剂中观察到独特的Zn-65结合条带，但在（ZnCl 2）-Zn-65孵育的制剂中未观察到。基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱分析表明，线粒体乌头酸酶（m-aconitase）是直接从Zn-MT接受Zn的蛋白质之一。与MT共免疫沉淀的是间乌头酸酶，而不是胞浆乌头酸酶（c-乌头酸酶）。这项研究表明，MT通过直接相互作用将锌转移到间乌头酸酶。(c)2005年爱思唯尔公司All rights reserved.
Previous studies have shown that in a cell-free system, metallothionein (MT) releases zinc when the environment becomes oxidized and the released zinc is transferred to a zinc-binding protein if such a protein is present. However, it is unknown whether and how zinc transfers from MT to other proteins in vivo. The present study was undertaken to test the hypothesis that if zinc transfer from MT to other proteins occurs in vivo, the transfer would proceed through a direct interaction between MT and a specific group of proteins. The heart extract obtained from MT-null mice was incubated with Zn-65-MT or (ZnCl2)-Zn-65 and the proteins receiving Zn-65 were separated by blue-native PAGE (BN-PAGE) or sodium dodecyl Sulfate-PAGE (SDS PAGE), and detected by autoradiography. A unique Zn-65-binding band was observed from the Zn-65-MT-incubated, but not the (ZnCl2)-Zn-65-incubated preparation. The analysis using matrix assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry revealed that mitochondrial aconitase (m-aconitase) was among the proteins accepting Zn directly from Zn-MT. The m-aconitase, not the cytosolic aconitase (c-aconitase), was co-immunoprecipitated with MT. This study demonstrates that MT transfers zinc to m-aconitase through a direct interaction. (c) 2005 Elsevier Inc. All rights reserved.