Department of Biomedical Science, Malmö University, 205 06 Malmö, Sweden.
Institute of Experimental Medicine, 197376 Saint-Petersburg, Russia Saint-Petersburg State University, 199034 Saint-Petersburg, Russia.
Bioelectrochemistry. 2021 Aug;140:107794. doi: 10.1016/j.bioelechem.2021.107794. Epub 2021 Mar 4.
High-performance autotolerant bioelectrodes should be ideally suited to design implantable bioelectronic devices. Because of its high redox potential and ability to reduce oxygen directly to water, human ceruloplasmin, HCp, the only blue multicopper oxidase present in human plasma, appears to be the ultimate biocatalyst for oxygen biosensors and also biocathodes in biological power sources. In comparison to fungal and plant blue multicopper oxidases, e.g. Myrothecium verrucaria bilirubin oxidase and Rhus vernicifera laccase, respectively, the inflammatory response to HCp in human blood is significantly reduced. Partial purification of HCp allowed to preserve the native conformation of the enzyme and its biocatalytic activity. Therefore, electrochemical studies were carried out with the partially purified enzyme immobilised on nanostructured graphite electrodes at physiological pH and temperature. Amperometric investigations revealed low reductive current densities, i.e. about 1.65 µA cm in oxygenated electrolyte and in the absence of any mediator, demonstrating nevertheless direct electron transfer based O bioelectroreduction by HCp for the first time. The reductive current density obtained in the mediated system was about 12 µA cm. Even though the inflammatory response of HCp is diminished in human blood, inadequate bioelectrocatalytic performance hinders its use as a cathodic bioelement in a biofuel cell.
高性能自容忍生物电极非常适合设计可植入的生物电子设备。由于其具有高氧化还原电位和直接将氧气还原为水的能力，人铜蓝蛋白（HCp）作为人血浆中唯一存在的蓝色多铜氧化酶，似乎是氧气生物传感器和生物电源生物阴极的最终生物催化剂。与真菌和植物蓝色多铜氧化酶（例如，疣孢漆斑菌胆红素氧化酶和盐肤木漆酶）相比，HCp 在人血液中的炎症反应显著降低。HCp 的部分纯化允许保留酶的天然构象及其生物催化活性。因此，在生理 pH 值和温度下，在纳米结构石墨电极上对部分纯化的酶进行了电化学研究。安培研究表明，在含氧电解质中，即使没有任何介体，还原电流密度也很低，约为 1.65 µA cm，然而，这首次证明了 HCp 基于直接电子转移的 O 生物还原。在介导系统中获得的还原电流密度约为 12 µA cm。尽管 HCp 在人血液中的炎症反应减弱，但生物电催化性能不足阻碍了其在生物燃料电池中作为阴极生物元件的应用。
