HIGH PRESSURE COOLING OF CYTOCHROME C OXIDASE

细胞色素 C 氧化酶的高压冷却

• 批准号: 7357733
• 负责人: SHELAGH M FERGUSON-MILLER
• 金额: $ 1.06万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7357733
• 关键词: PRESSURE; COOLING; CYTOCHROME; OXIDASE

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. Cytochrome c oxidase (CcO) is the terminal enzyme in the electron transfer chain in eukaryotes and many bacteria. It provides the final electron sink by accepting electrons from cytochrome c and passing them on to oxygen to form water. Over the past decade, several x-ray crystal structures of aa3-type oxidases have been determined from bovine heart mitochondria and bacteria. This new wealth of structural information, combined with spectroscopic and site-directed mutagenesis studies, has greatly enhanced our understanding of the structure/function aspects of this multisubunit membrane protein complex. However, the mechanism of vectorial translocation of protons and its coupling to electron transfer and oxygen reduction is yet to be solved. Although we now have crystals diffracting to 2.35 A resolution, a key question is the arrangement of water molecules in the structure that form proton transfer pathways, as well as changes in water arrangement in mutant forms, hence the need for higher quality diffraction data. It was reported that protein crystals cryo-cooled at high pressure (200Mpa) diffract excellently even without any penetrating cryoprotectants. So in this experiment, cytochrome c oxidase crystals will be handled by high pressure cooling method and high quality data sets will be collected.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。细胞色素C氧化酶（CCO）是真核生物和许多细菌中电子转移链中的末端酶。它通过接受细胞色素C的电子并将其传递到氧气中以形成水来提供最终的电子水槽。 在过去的十年中，通过牛心脏线粒体和细菌确定了AA3型氧化酶的几种X射线晶体结构。这种新的结构信息，结合光谱和定向诱变研究，极大地增强了我们对这种多亚基膜蛋白复合物的结构/功能方面的理解。然而，质子的矢量易位及其与电子转移和还原氧的耦合的机理尚未解决。 尽管我们现在的晶体衍射为2.35 A分辨率，但一个关键问题是结构中水分子的排列，形成质子转移途径，以及突变体形式的水排列的变化，因此需要更高质量的衍射数据。 据报道，即使没有任何穿透性冷冻保护剂，蛋白质晶体在高压（200MPA）衍射剂的冷冻冷却也出色。因此，在此实验中，将通过高压冷却方法来处理细胞色素C氧化酶晶体，并收集高质量的数据集。