Functional control via heme-backbone interactions in respiratory and photosynthetic heme proteins observed with x-ray nuclear absorption spectroscopy

本研究项目的最终目标是了解血红素蛋白的生物活性是如何受到蛋白质骨架与血红素基团动态相互作用的影响。x射线同步加速器核吸收光谱的进展，首次允许测量血红素铁在各种氧化、温度、配体结构和光激发条件下的态的振动密度。这些详细的动态信息将在先进光子源的实验中从跨越一系列血红蛋白-骨架偶联结构的蛋白质中获得。与微过氧化物酶和其他截断版本血红素蛋白的结果比较将有助于说明非局部血红素-骨干相互作用。这一综合的振动数据集可用于改进血红素蛋白动力学的非线性正态计算中使用的力常数。该项目由数学和物理科学理事会物理部和生物科学理事会分子生物物理学项目共同支持。

The ultimate goal of this research project is an understanding of how the biological activity of heme proteins is influenced by the dynamic interaction of the protein backbone with the heme group. Advances in x-ray synchrotron nuclear absorption spectroscopy permit, for the first time, measurement of the heme Fe vibrational density of states under various conditions of oxidation, temperature, ligand configuration, and optical excitation. This detailed dynamic information will be obtained in experiments at the Advanced Photon Source from proteins that span a range of heme-backbone coupling configurations. Comparisons with results from microperoxidase and other truncated versions of heme proteins will help illustrate the non-local heme-backbone interactions. This comprehensive set of vibrational data with then be used to refine the force constants used in non-linear normal mode calculations of heme protein dynamics. This project is jointly supported by the Physics Division in the Mathematical and Physical Sciences Directorate and by the Molecular Biophysics program in the Directorate for Biological Sciences.