ELECTRON-TRANSFER MEMBRANE PROTEIN COMPLEXES OF THE RESPIRATORY CHAIN

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 线粒体和细菌的呼吸链将底物氧化的电化学氧化还原能量转化为氢离子的电化学梯度，可用于需要能量的过程，如ATP的生成和主动运输。电子转移反应和质子转移之间的能量耦合是通过多亚单位膜蛋白复合体实现的。除了它们的生物学重要性外，这些都是很好的膜蛋白，因为它们在细胞中的丰度很高，因此不需要过度表达。一个成熟的项目是细胞色素Bc1复合体(复合体III)，它是我们从一些生物体中结晶出来的。现在我们正在研究缓蚀剂与底物的结合模式，观察构象变化，并通过优化脱水和冷冻条件来推动分辨率(到目前为止为2.0°)。对于化合物II，我们已经将禽酶结晶并将晶体分阶段，现在我们正在努力提高分辨率和解决结构问题。对于络合物I，我们仍在筛选结晶条件。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The respiratory chains of mitochondria and bacteria convert electrochemical redox energy from the oxidation of substrates into an electrochemical gradient of the hydrogen ion, which can be utilized for energy-requiring processes such as ATP generation and active transport. The energy coupling between electron transfer reactions and proton translocation is carried out by multi-subunit membrane protein complexes. In addition to their biological importance, these are good membrane proteins to get started with because of their high abundance in the cell which obviates the need for overexpression. A mature project is the cytochrome bc1 complex (Complex III), which we have crystallized from a number of organism. Now we are studying binding mode of inhibitors and substrates, looking at conformational changes, and pushing the resolution (2.0 ¿ so far) by optimizing dehydration and freezing conditions. For Complex II we have crystallized the avian enzyme and phased the crystals, now we are working on improving resolution and solving the structure. With Complex I we are still screening crystallization conditions.