Structure-dependent electrical conductivity of protein: its differences between alphadomain and beta-domain structures
Structure-dependent electrical conductivity of protein: its differences between alphadomain and beta-domain structures
复制标题
蛋白质的结构依赖性电导率：α结构域和β结构域结构之间的差异
DOI：
10.1088/0957-4484/26/12/125702
复制
发表时间：
2015
期刊：
影响因子：
3.5
通讯作者：
Yue Zheng
中科院分区：
文献类型：
--
作者：
X. Y. Zhang;J. Shao;S. X. Jiang;B. Wang;Yue Zheng
蛋白质α-结构域和β-结构域的电子传递已经得到了全面的研究。对蛋白质结构依赖的电子传递进行了实验测量和理论模拟，理论和实验结果均表明α-结构域和β-结构域的电导率存在显著差异。通过控制扫描隧道显微镜（STM）的反馈系统，分别测定了单个α-结构域蛋白血红蛋白（Hgb）和单个β-结构域蛋白超氧化物歧化酶（SOD）的电导。Hgb的电流信号明显更强，说明α-结构域的导电性更强。为了证实我们的发现，我们基于第一性原理计算分析了SOD中β-结构域和Hgb中α-结构域的分子轨道。正如预期的那样，α-域的隧穿输运和跳变都更有效，这表明电子更容易通过α-域进行输运，这与我们的实验数据非常一致。为了解释我们的结果，我们仔细分析了α-和β-结构域的分子结构，并表明解释应该在于α-结构域和β-结构域之间的填充模式的差异。该研究对分子电子学的应用前景具有重要意义。
Electron transports in the α-domain and β-domain of proteins have been comprehensively investigated. The structure-dependent electron transport of proteins has been experimentally measured and theoretically simulated, and both the theoretical and experimental results demonstrate significant differences in electrical conductivity between the α-domain and β-domain. By controlling the feedback system of the scanning tunneling microscope (STM), the conductance of a single α-domain protein hemoglobin (Hgb) and a β-domain protein superoxide dismutase enzyme (SOD) were measured, respectively. The current signal of Hgb is obviously stronger, indicating that the α-domain is more conductive. To confirm our finding, molecular orbitals of both the β-domain in SOD and α-domain in Hgb have been analyzed based on first-principles calculations. As expected, tunneling transport and hopping in the α-domain are both more efficient, indicating that it is easier for electrons to transport through the α-domain, which are in great agreement with our experimental data. In order to explain our results, molecular structures of α-and β-domains have been carefully analyzed and show that the explanation should lie in the differences in packing mode between the α-domain and β-domain. This research should be very important to application prospects in molecular electronics.