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。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。细胞色素c氧化酶（Cytochrome c oxidase，CcO）是真核生物和许多细菌中电子传递链的末端酶。它通过接受来自细胞色素c的电子并将其传递给氧气以形成水来提供最终的电子库。 在过去的十年中，已经从牛心脏线粒体和细菌中确定了几种aa 3型氧化酶的x射线晶体结构。这一新的丰富的结构信息，结合光谱和定点诱变研究，大大提高了我们的理解，这种多亚基膜蛋白复合物的结构/功能方面。然而，质子的矢量移位及其与电子转移和氧还原的耦合机制尚未得到解决。 虽然我们现在有衍射到2.35 A分辨率的晶体，但关键问题是形成质子转移途径的结构中水分子的排列，以及突变形式中水排列的变化，因此需要更高质量的衍射数据。 据报道，蛋白质晶体在高压（200 Mpa）下冷冻，即使没有任何渗透性的冷冻保护剂，也表现出良好的冷冻效果。因此，在本实验中，细胞色素c氧化酶晶体将通过高压冷却方法处理，并将收集高质量的数据集。