RUI: Biophysical and Electron Paramagnetic Resonance Studies: Energetics of the Oxygen-Evolving Complex and New Curricula for Undergraduates

主要研究目标是从能量学角度表征高等植物放氧复合体（OEC）锰簇的氧化态变化。 这将通过监测两个电子顺磁共振（EPR）信号来进行，g=2处的多线信号和g=4处的宽信号，与氧化态之一S2相关。 此外，与S1（S2之前的状态）相关的g=4.8处的偶数自旋EPR信号的存在将使用并行模式检测来确认，并且随后用于监视S1。 具体的研究目标包括：确认在g=4时与S2信号相关的状态- 确定与S1和S2-g = 4、S2-g=4和S2-mult以及S2-mult和S3相关联的状态之间的激活能势垒，S3是在S2之后的状态;与S1，S2-g=4和S2-mult相关的状态的相对自由能的测定;以及在抑制剂氨存在下的能垒和相对自由能的研究。 为了实现这些目标，S2信号和S1信号（如果存在）的幅度将在一系列平衡和动力学实验中进行测量，这些实验在一定的照明温度范围内进行。 这些数字将与每个州的人口有关。 建议的教育活动是在雅阁与化学系目前的计划，以发展一个浓度或专业的生物化学。 教育目标包括：一个学期的生物化学实验室课程的发展;一系列的生物物理专题讲座将作为第二学期的入门课程的一部分;和一套EPR实验，用于本科实验室。 大学生的EPR实验将包括一些在生物化学中有应用的实验，这些实验目前在化学教育文献中还没有。 %%%

9600925 Haddy The primary research goal is to characterize the oxidation state changes of the manganese cluster of the oxygen evolving complex (OEC) of higher plants in terms of energetics. This will be carried out by monitoring two electron paramagnetic resonance (EPR) signals, a multiline signal at g=2 and a broad signal at g=4, associated with one of the oxidation states, S2. In addition, the presence of an even spin EPR signal at g=4.8 associated with S1, the state preceding S2, will be confirmed using parallel mode detection and subsequently used to monitor S1. The specific research objectives include: confirmation that the state associated with the S2 signal at g=4 (designated S2-g=4) precedes the state associated with the S2 multiline signal (S2-mult); determination of the activation energy barriers between the states associated with S1 and S2-g=4, S2-g=4 and S2-mult, and S2-mult and S3, the state that follows S2; determination of the relative free energies of the states associated with S1, S2-g=4, and S2-mult; and investigation of the energy barriers and relative free energies in the presence of the inhibitor ammonia. To achieve these objectives, the magnitudes of the S2 signals and if present the S1 signal will be measured in a series of equilibrium and kinetics experiments performed over a range of illumination temperatures. The magnitudes will be related to the population in each state. The educational activities proposed are in accord with the Chemistry Department's current plans to develop a concentration or major in biochemistry. The education objectives include the development of: a one-semester biochemistry laboratory course; a series of lectures on biophysical topics to be given as part of the second semester introductory course; and a set of EPR experiments for use in undergraduate laboratories. The EPR experiments for undergraduates will include some that have applications in biochemistry and are not presently available in the chemical education literature. %%%