突变大肠杆菌细胞色素bd-I氧化酶血红素b的环境会使其氧化还原电位改变200毫伏，而不会使该酶失活。
Mutating the environment of heme b of E. coli cytochrome bd-I oxidase shifts its redox potential by 200 mV without inactivating the enzyme.
作者信息
Makarchuk Iryna, Gerasimova Tatjana, Kägi Jan, Wohlwend Daniel, Melin Frédéric, Friedrich Thorsten, Hellwig Petra
机构信息
Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany.
Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, 67000 Strasbourg, France; Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr 21, 79104 Freiburg, Germany.
出版信息
Bioelectrochemistry. 2023 Jun;151:108379. doi: 10.1016/j.bioelechem.2023.108379. Epub 2023 Jan 30.
Cytochrome bd-I catalyzes the reduction of oxygen to water with the aid of hemes b, b and d. Here, effects of a mutation of E445, a ligand of heme b and of R448, hydrogen bonded to E445 are studied electrochemically in the E. coli enzyme. The equilibrium potential of the three hemes are shifted by up to 200 mV in these mutants. Strikingly the E445D and the R448N mutants show a turnover of 41 ± 2 % and 20 ± 4 %, respectively. Electrocatalytic studies confirm that the mutants react with oxygen and bind and release NO. These results point towards the ability of cytochrome bd to react even if the electron transfer is less favorable.
细胞色素bd-I借助血红素b、b和d催化氧气还原为水。在此，对大肠杆菌中的该酶进行电化学研究，考察血红素b的配体E445以及与E445形成氢键的R448发生突变的影响。在这些突变体中，三种血红素的平衡电位移动高达200 mV。引人注目的是，E445D突变体和R448N突变体的周转率分别为41±2%和20±4%。电催化研究证实，这些突变体与氧气发生反应，并能结合和释放一氧化氮。这些结果表明，即使电子传递不太有利，细胞色素bd仍具有反应能力。
Zotero 插件