Abstract:
Cellobiose dehydrogenase (CDH) is a flavocytochrome with a history of bioelectrochemical research dating back to 1992. During the years, it has been shown to be capable of mediated electron transfer (MET) and direct electron transfer (DET) to a variety of electrodes. This versatility of CDH originates from the separation of the catalytic flavodehydrogenase domain and the electron transferring cytochrome domain. This uncoupling of the catalytic reaction from the electron transfer process allows the application of CDH on many different electrode materials and surfaces, where it shows robust DET. Recent X-ray diffraction and small angle scattering studies provided insights into the structure of CDH and its domain mobility, which can change between a closed-state and an open-state conformation. This structural information verifies the electron transfer mechanism of CDH that was initially established by bioelectrochemical methods. A combination of DET and MET experiments has been used to investigate the catalytic mechanism and the electron transfer process of CDH and to deduce a protein structure comprising of mobile domains. Even more, electrochemical methods have been used to study the redox potentials of the FAD and the haem b cofactors of CDH or the electron transfer rates. These electrochemical experiments, their results and the application of the characterised CDHs in biosensors, biofuel cells and biosupercapacitors are combined with biochemical and structural data to provide a thorough overview on CDH as versatile bioelectrocatalyst.
摘要:
纤维二糖脱氢酶(CDH)是一种黄素细胞色素,其生物电化学研究历史可追溯到1992年。多年来,它已被证明能够介导电子转移(MET)和直接电子转移(DET)到各种电极。CDH的这种多功能性源于催化黄素脱氢酶结构域和电子转移细胞色素结构域的分离。催化反应与电子转移过程的这种解偶联允许CDH在许多不同的电极材料和表面上应用,在那里它显示健壮的DET。最近的X射线衍射和小角散射研究提供了对CDH结构及其域迁移率的见解,可以在封闭状态和开放状态构象之间变化。这些结构信息验证了最初通过生物电化学方法建立的CDH的电子转移机制。DET和MET实验的组合已用于研究CDH的催化机理和电子转移过程,并推导出包含移动域的蛋白质结构。甚至更多,电化学方法已用于研究FAD的氧化还原电位和CDH的血红素b辅因子或电子转移速率。这些电化学实验,他们的结果以及表征的CDHs在生物传感器中的应用,将生物燃料电池和生物超级电容器与生化和结构数据相结合,为CDH作为多功能生物电催化剂提供了全面的概述。