Gated Electron Transfer: Direct Correlation with Redox Protein Dynamics

无机化学、生物无机化学和金属有机化学项目的这一奖项支持丹佛大学的Bruce E.Bowler教授的研究，该研究旨在研究蛋白质中门控电子转移反应的基本方面，该反应调节代谢途径中的电子流动。这项研究利用了电子传输蛋白iso-1-细胞色素c的变体，这些变体被用来改变铁位点的还原潜力。用pH跳跃停流法测定修饰蛋白质中的电子转移速率。将测量所有变种的门控反应的热力学和依赖于温度的动力学。在准一级条件下，用停流法可以监测异-1-细胞色素C异构体与小的无机络合物的电子转移反应的温度相关动力学。通过增加无机氧化还原试剂的浓度，观察到的电子转移速率将从非栅极条件平稳地变化到栅极条件。通过比较ET在门控条件下的激活参数和速率常数与门控过程中的激活参数和速率常数，可以实现门控ET与构象门控反应的直接关联。蛋白质构象的变化与蛋白质氧化状态的变化有关，在许多重要蛋白质中发挥着关键作用，例如在产生ATP的电子转移链中的电子转移性质。这项研究的结果也可以应用于生物技术电子设备中的门控电流。这项研究还将培训不同层次的学生，重点是本科生女性和代表性不足的少数族裔学生。

This award in the Inorganic, Bioinorganic and Organometallic Chemistry Program supports research by Professor Bruce E. Bowler at the University of Denver to investigate fundamental aspects of gated electron transfer reactions in proteins, which regulate electron flow in metabolic pathways. The research capitalizes on variants of the electron transport protein, iso-1-cytochrome c which are used to vary the reduction potential of the iron site. Electron transfer rates in the modified proteins will be measured by pH jump stopped-flow methods. The thermodynamics and temperature-dependent kinetics of the gating reaction will be measured for all variants. Temperature-dependent kinetics for the electron transfer reactions of the iso-1-cytochrome c variants with small inorganic complexes will be monitored by stopped-flow methods under pseudo first order conditions. By increasing the concentration of the inorganic redox reagent, the observed electron transfer rates will be varied smoothly from non-gating to gating conditions. By comparing the activation parameters and rate constants for ET under gating conditions with those for the gating process, direct correlation of gated ET with a conformational gating reaction will be accomplished. Protein conformational changes linked to changes in the oxidation state of the protein play key roles in gating electron transfer properties in a wide range of important proteins, such as those in the ATP-producing electron transfer chain. Results learned in this study can also be applied to gating currents in biotechnological electronic devices. This research will also train students at various levels, with an emphasis on undergraduate women and underrepresented minority students.