Laboratoire de Bioelectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg, CNRS, 67081 Strasbourg, France.
Institut für Biochemie, Fakultät für Chemie und Pharmazie, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany.
Molecules. 2020 Jul 16;25(14):3240. doi: 10.3390/molecules25143240.
The cytochrome oxidase catalyzes the reduction of oxygen to water in bacteria and it is thus an interesting target for electrocatalytic studies and biosensor applications. The oxidase is completely embedded in the phospholipid membrane. In this study, the variation of the surface charge of thiol-modified gold nanoparticles, the length of the thiols and the other crucial parameters including optimal phospholipid content and type, have been performed, giving insight into the role of these factors for the optimal interaction and direct electron transfer of an integral membrane protein. Importantly, all three tested factors, the lipid type, the electrode surface charge and the thiol length mutually influenced the stability of films of the cytochrome oxidase. The best electrocatalytic responses were obtained on the neutral gold surface when the negatively charged phosphatidylglycerol (PG) was used and on the charged gold surface when the zwitterionic phosphatidylethanolamine (PE) was used. The advantages of the covalent binding of the membrane protein to the electrode surface over the non-covalent binding are also discussed.
细胞色素氧化酶在细菌中将氧气还原为水，因此它是电催化研究和生物传感器应用的有趣目标。该氧化酶完全嵌入磷脂膜中。在这项研究中，对巯基修饰的金纳米粒子的表面电荷、巯基的长度以及其他关键参数（包括最佳磷脂含量和类型）进行了研究，深入了解了这些因素对完整膜蛋白的最佳相互作用和直接电子转移的作用。重要的是，所测试的三个因素，脂质类型、电极表面电荷和硫醇长度相互影响细胞色素氧化酶膜的稳定性。当使用带负电荷的磷脂酰甘油（PG）时，在中性金表面上获得最佳的电催化响应，而当使用两性离子磷脂酰乙醇胺（PE）时，在带电荷的金表面上获得最佳的电催化响应。还讨论了将膜蛋白通过共价键连接到电极表面相对于非共价键连接的优势。
