通过原位紫外和圆二色光谱电化学监测电极表面微观结构对细胞色素c中电子转移诱导的构象变化的影响。

Effect of electrode surface microstructure on electron transfer induced conformation changes in cytochrome c monitored by in situ UV and CD spectroelectrochemistry.

作者信息

Jiang Xiue, Zhang Zheling, Bai Hanying, Qu Xiaohu, Jiang Junguang, Wang Erkang, Dong Shaojun

机构信息

State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.

出版信息

Spectrochim Acta A Mol Biomol Spectrosc. 2005 Mar;61(5):943-51. doi: 10.1016/j.saa.2004.05.036.

DOI:10.1016/j.saa.2004.05.036

PMID:15683801

Abstract

Electrochemical redox processes of bovine heart cytochrome c were investigated by in situ UV-vis and CD spectroelectrochemistry at bare glassy carbon electrode (GCE) and single-wall carbon nanotubes (SWNTs) modified glassy carbon electrode (SWNTs/GCE) using a long optical path thin layer cell. The spectra obtained at GCE and SWNTs/GCE reflect electrode surface microstructure-dependent changes in protein conformation during redox transition. Potential-dependent conformational distribution curves of cytochrome c obtained by analysis of in situ circular dichroism (CD) spectra using singular value decomposition least square (SVDLS) method show that SWNTs can retain conformation of cytochrome c. Some parameters of the electrochemical reduction process, i.e. the product of electron transfer coefficient and number of electrons (alpha n = 0.3), apparent formal potential (E0' = 0.04 V), were obtained by double logarithmic analysis and standard heterogeneous electron transfer rate constant k0 was obtained by electrochemistry and double logarithmic analysis, respectively.

摘要

使用长光程薄层池，通过原位紫外可见光谱和圆二色光谱电化学方法，在裸玻碳电极（GCE）和单壁碳纳米管（SWNTs）修饰的玻碳电极（SWNTs/GCE）上研究了牛心细胞色素c的电化学氧化还原过程。在GCE和SWNTs/GCE上获得的光谱反映了氧化还原转变过程中蛋白质构象随电极表面微观结构的变化。通过使用奇异值分解最小二乘法（SVDLS）分析原位圆二色（CD）光谱得到的细胞色素c的电位依赖性构象分布曲线表明，SWNTs可以保留细胞色素c的构象。通过双对数分析获得了电化学还原过程的一些参数，即电子转移系数与电子数的乘积（αn = 0.3）、表观形式电位（E0' = 0.04 V），并分别通过电化学和双对数分析获得了标准异相电子转移速率常数k0。