STRUCTURE & DYNAMICS OF ELECTRON-TRANSFER INTERMEDIATES OF PHOTOSYNTHESIS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 基于我们以前的高场/高频EPR蛋白质系统的工作，我们将专注于定向分辨脉冲高场EPR光谱和相关的双共振技术应用于野生型和位点特异性突变体的光合生物，特别是反应中心（RC）从非产氧紫色细菌和光系统I和II（PS I，PS II）从产氧蓝藻和藻类。突变RC制剂将被Fe-Zn取代，并通过先进的多频/多共振EPR技术（在MPI和ACERT运行）在冷冻溶液样品中进行研究。到目前为止所使用的实验方法计划通过ACERT提供的独特仪器方法进行扩展或与之结合，这些方法在很大程度上补充了MPI M？lheim的EPR设施。这一选择与ACERT在设计和构建新型EPR仪器方面的丰富经验相结合，将导致创新和技术进步，超越目前已知的生物EPR光谱学。作为一个例子，它计划结合联合收割机ACERT在8-18 GHz范围内的停流EPR的专业知识与我们的初步快速流动EPR实验在95 GHz。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Based on our previous high-field/high-frequency EPR work on protein systems , we will focus on orientation-resolved pulsed high-field EPR spectroscopy and related double-resonance techniques applied to wild type and site-specific mutants of photosynthetic organisms, in particular the reaction centers (RCs) from non-oxygenic purple bacteria and photosystems I and II (PS I, PS II) from oxygenic cyanobacteria and algae. The mutant RC preparations will be Fe-to-Zn substituted and studied by advanced multifrequency/multiresonance EPR techniques (operating at the MPI and at ACERT) in frozen-solution samples. The experimental methods used so far are planned to be extended by or combined with the unique instrumental methods available at ACERT, which are largely complementary to the EPR facilities at the MPI M¿lheim. This option, in conjunction with the immense experience in designing and constructing novel EPR instrumentation at ACERT, will result in innovations and technological advances beyond what is presently known in bio-oriented EPR spectroscopy. As an example, it is planned to combine the ACERT expertise in stopped-flow EPR in the 8-18 GHz range with our preliminary fast-flow EPR experiments at 95 GHz.