...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >P67-phox-mediated NADPH oxidase assembly: imaging of cytochrome b558 liposomes by atomic force microscopy.
【24h】

P67-phox-mediated NADPH oxidase assembly: imaging of cytochrome b558 liposomes by atomic force microscopy.

机译：P67-phox介导的NADPH氧化酶组装：通过原子力显微镜对细胞色素b558脂质体成像。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

NADPH oxidase activity depends on the assembly of the cytosolic activating factors, p67-phox, p47-phox, p40-phox, and Rac with cytochrome b(558). The transition from an inactive to an active oxidase complex induces the transfer of electrons from NADPH to oxygen through cytochrome b(558). The assembly of oxidase complex was studied in vitro after reconstitution in a heterologous cell-free assay by using true noncontact mode atomic force microscopy. Cytochrome b(558) was purified from neutrophils and Epstein-Barr virus-immortalized B lymphocytes and incorporated into liposomes. The effect of protein glycosylation on liposome size and oxidase activity was investigated. The liposomes containing the native hemoprotein purified from neutrophils had a diameter of 146 nm, whereas after deglycosylation, the diameter was reduced to 68 nm, although oxidase activity was similar in both cases. Native cytochrome b(558) was used after purification in reconstitution experiments to investigate the topography of NADPH oxidase once it was assembled. For the first time, atomic force microscopy illustrated conformational changes of cytochrome b(558) during the transition from the inactive to the active state of oxidase; height measurements allow the determination of a size of 4 nm for the assembled complex. In the processes that were studied, p67-phox displayed a critical function; it was shown to be involved in both assembly and activation of oxidase complex while p47-phox proceeded as a positive effector and increased the affinity of p67-phox with cytochrome b(558), and p40-phox stabilizes the resting state. The results suggest that although an oligomeric structure of oxidase machinery has not been demonstrated, allosteric regulation mechanisms may be proposed.
机译：NADPH氧化酶的活性取决于细胞色素激活因子，p67-phox，p47-phox，p40-phox和Rac与细胞色素b（558）的组装。从无活性的氧化酶到有活性的氧化酶复合物的转变诱导电子通过细胞色素b从NADPH转移到氧气（558）。使用真正的非接触模式原子力显微镜在异源无细胞试验中重组后，体外研究了氧化酶复合物的组装。从中性粒细胞和爱泼斯坦-巴尔病毒永生化的B淋巴细胞中纯化细胞色素b（558），并掺入脂质体中。研究了蛋白质糖基化对脂质体大小和氧化酶活性的影响。含有从嗜中性粒细胞中纯化的天然血蛋白的脂质体的直径为146 nm，而去糖基化后的直径减小到68 nm，尽管两种情况下的氧化酶活性相似。天然细胞色素b（558）在纯化后用于重建实验，以研究NADPH氧化酶组装后的形貌。原子力显微镜首次说明了细胞色素b（558）从非活性状态转变为活性状态的过程中的构象变化。高度测量可以确定组装的复合体的4 nm尺寸。在研究的过程中，p67-phox发挥了关键作用。它被证明参与氧化酶复合物的组装和激活，而p47-phox作为阳性效应子起作用，并增加了p67-phox与细胞色素b（558）的亲和力，而p40-phox则稳定了静止状态。结果表明，尽管尚未证明氧化酶机制的低聚结构，但可能提出了变构调节机制。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号