CAREER: Sub-picosecond spectroscopy and imaging of mitochondrial respiratory chain redox

我们呼吸的几乎所有氧气都是由线粒体消耗的，线粒体是我们每个细胞中发现的微小的产生能量的细胞器。虽然线粒体缺陷很少见，但它们会导致极度疲劳、头痛、视力丧失，甚至过早死亡。弄清楚如何修复有缺陷的线粒体是非常困难的，因为每个病例都是独特的，而且我们缺乏充分测试单个线粒体对干预的反应的技术。这个项目将开发探测线粒体的新工具，基于激光与线粒体用来产生能量的关键分子的相互作用。具体来说，本提案的目标是用亚细胞分辨率对线粒体呼吸电子转移血红素进行无标记氧化还原测量。该小组将使用泵探针显微镜，结合相干分子振动和电子激发态弛豫的测量来实现这一目标。他们将通过模拟电子转移血红素的激发态动力学来优化泵浦和探针波长的选择，并在制备呼吸链状态的活细胞和组织上验证该方法。作为“更广泛的影响”的一部分，他们将设计一个STEM活动工具包，以有趣和引人入胜的方式向高中生教授通过光谱学观察新陈代谢的核心概念。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nearly all the oxygen we breathe is consumed by our mitochondria, tiny energy-producing organelles found in each of our cells. Though mitochondrial defects are rare, they can cause extreme fatigue, headaches, loss of eyesight, and even premature death. Figuring out how to repair defective mitochondria is surprisingly difficult because every case is unique, and we lack the technology to fully test how individual mitochondria respond to interventions. This project will develop new tools for probing mitochondria, based on laser interactions with key molecules that mitochondria use to produce energy.Specifically, the goal of this proposal is label-free redox measurement of the mitochondrial respiratory electron transfer hemes with subcellular resolution. The group will achieve this using pump-probe microscopy, combining measurements of coherent molecular vibrations and electronic excited-state relaxation. They will optimize the selection of pump and probe wavelengths by modeling the excited-state dynamics of electron transfer hemes and validate the approach on live cells and tissues with prepared respiratory chain states. As part of the Broader Impacts, they will design a STEM activity kit to teach high school students core concepts in seeing metabolism through optical spectroscopy in a fun and engaging way.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.