Solid-State Electron Transport across Azurin: From a Temperature-Independent to a Temperature-Activated Mechanism
Solid-State Electron Transport across Azurin: From a Temperature-Independent to a Temperature-Activated Mechanism
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DOI：
10.1021/ja109989f
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发表时间：
2011-03-02
影响因子：
15
通讯作者：
Cahen, David
中科院分区：
文献类型：
--
作者：
Sepunaru, Lior;Pecht, Israel;Cahen, David
研究了电子通过集成在固态结中的蛋白质传递的电流-电压值的温度依赖性。这些测量是从80到400 K[高于azin （Az）的变性温度]使用我们之前描述的Si/Az/Au结进行的。在整个范围内，通过类似于3.5 nm厚的Az结的电流与温度无关。与之形成鲜明对比的是，对于锌取代和载子Az（即贫铜Az），观察到热活化行为。这些显著的温度依赖性差异归因于Cu离子在固态电子传递过程中作为氧化还原中心的关键作用。因此，虽然Cu能够实现与温度无关的电子传递，但在其去除后，多肽仅能够支持热激活的传递。
The temperature dependence of current-voltage values of electron transport through proteins integrated into a solid-state junction has been investigated. These measurements were performed from 80 up to 400 K [above the denaturation temperature of azurin (Az)] using Si/Az/Au junctions that we have described previously. The current across the similar to 3.5 nm thick Az junction was temperature-independent over the complete range. In marked contrast, for both Zn-substituted and apo-Az (i.e., Cu-depleted Az), thermally activated behavior was observed. These striking temperature-dependence differences are ascribed to the pivotal function of the Cu ion as a redox center in the solid-state electron transport process. Thus, while Cu enabled temperature-independent electron transport, upon its removal the polypeptide was capable only of supporting thermally activated transport.