How does respiratory complex I pumps protons? Finding the missing link using EPR spectroscopy.

英国人口年龄的增长是我们社会和经济面临的主要挑战之一，通过增加我们尽可能健康的生活年限，最大限度地发挥最有经验的人的贡献至关重要。线粒体呼吸链对ATP的产生是必不可少的，也是活性氧物种的主要来源，被认为对我们的衰老速度有重大影响。此外，呼吸链的缺陷是线粒体疾病的原因--这些疾病很少见，但其后果往往非常严重，如果不是致命的话。他们的诊断充满了困难，而且没有治愈的方法。复合体I是线粒体呼吸链中一个关键但知之甚少的元件，我们建议通过多学科的方法来阐明这一关键酶机制的一个特别重要的方面。我们将研究牛酶，这是人类络合物I的近亲，特别是使用电子顺磁共振(EPR)光谱，这是一种研究具有未配对电子的化学中心的强大方法。在复合体I中，这种未配对的电子自然存在或可以在机械上高度信息量的位置产生，我们将通过先进的脉冲EPR和生化方法利用它们提供的信息。我们的工作将是在获得人体中最重要、最大和最神秘的酶之一的分子机制的完整图景方面向前迈出的重要一步，对延长我们的健康寿命以及识别和治疗由复合体I功能障碍引起的线粒体疾病具有长期意义。我们建议的研究计划将立即对英国科学产生影响，学术受益者将在不同的研究学科范围内。我们将为EPSRC PDRA(以及至少两名玛丽女王大学本科生研究项目的学生)提供高质量的跨学科培训，提供化学和生物相互作用的专业知识，以及基本生化问题的量化方法。

The rising age of the UK population presents one of the major challenges to our society and economy and it is vital that we maximise the contribution of the most experienced individuals by increasing the number of years we live in best possible health. The mitochondrial respiratory chain, which is essential for the production of ATP and a prime source of reactive oxygen species, is thought to have a major influence on the rate at which we age. Moreover, defects in the respiratory chain are responsible for mitochondrial diseases - these are rare, but their outcome is often very severe, if not fatal. Their diagnosis is fraught with difficulties and there is no cure. Complex I is a crucial but poorly understood element in the mitochondrial respiratory chain and we propose to elucidate a particularly important aspect of the mechanism of this essential enzyme by employing a multidisciplinary approach. We will study the bovine enzyme, a close relative of human complex I, employing in particular electron paramagnetic resonance (EPR) spectroscopy, a powerful method for investigating chemical centres having unpaired electrons. In complex I such unpaired electrons are naturally present or can be generated in mechanistically highly informative locations and we will harness the information they provide through advanced pulse EPR and biochemical methods.Our work will constitute a major step forward in obtaining a complete picture of the molecular mechanism of one of the most important, largest and most enigmatic enzymes in our bodies, with long-term implications for increasing our healthy lifespan and for the recognition and treatment of mitochondrial diseases resulting from complex I dysfunction. Our proposed research program will have immediate impact on UK science, with academic beneficiaries in a diverse range of research disciplines. We will provide top-quality interdisciplinary training for the EPSRC PDRA (and at least two Queen Mary University undergraduate research project students), to provide expertise at the interface of chemistry and biology, with a quantitative approach to fundamental biochemical problems.