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

这项研究项目的最终目标是了解蛋白质骨架与血红素基团的动态相互作用如何影响血红素蛋白的生物活性。X-射线同步加速器核吸收光谱的进展首次使测量不同氧化、温度、配体构型和光激发条件下的血红素铁的振动态密度成为可能。这一详细的动态信息将在高级光子源的实验中从跨越一系列血红素-主干耦合配置的蛋白质中获得。与微量过氧化物酶和其他截短版本的血红素蛋白质的结果进行比较，将有助于说明非本地的血红素-主干相互作用。这套全面的振动数据可用于改进用于血红素蛋白质动力学的非线性简正模式计算的力常数。该项目由数学和物理科学局的物理司和生物科学局的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.