...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Antioxidants and redox signalling >Cell-surface NAD(P)H-oxidase: relationship to trans-plasma membrane NADH-oxidoreductase and a potential source of circulating NADH-oxidase.
【24h】

Cell-surface NAD(P)H-oxidase: relationship to trans-plasma membrane NADH-oxidoreductase and a potential source of circulating NADH-oxidase.

机译：细胞表面NAD（P）H-氧化酶：与跨质膜NADH-氧化还原酶和循环NADH-氧化酶的潜在来源的关系。

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The surface of mammalian cells faces an oxidizing environment that has the potential to damage proteins, lipids, and carbohydrates to which it is exposed. In contrast, the cytoplasm is reducing and its redox state is tightly regulated. Trans-plasma membrane oxidoreductases that shift electrons from cytosolic NADH to external electron acceptors such as oxygen are widely involved in cellular redox control. They reduce oxygen to water and may generate reactive oxygen species such as superoxide and hydrogen peroxide. In addition, external NAD(P)H-oxidases have been demonstrated on intact cells and as eluted proteins, but the relationship between trans-plasma membrane NADH-oxidoreductases and cell-surface NAD(P)H-oxidases is not known. To investigate further the relationship between plasma membrane NAD(P)H-oxidoreductases, and to gain insight into the physiological functions of these redox active membrane proteins, we have adapted a simple colorimetric assay for measuring the trans-plasma membrane NADH-oxidoreductase activity of viable cells to measure NAD(P)H-oxidase at the cell surface in real time. Using the cell-impermeable tetrazolium salt WST-1 in the presence of NADH or NADPH, but in the absence of an intermediate electron acceptor, we show that cell-surface NAD(P)H-oxidase is widely expressed on mammalian cells, being more abundant on rapidly proliferating cells than on resting neutrophils and spleen cells. The ratio of cofactor dependence of NAD(P)H-oxidase (NADH:NADPH) varied widely between different cells (0.7-5.2), suggesting a family of cell surface oxidases or that the activity of these enzymes may be modulated in various ways. Comparison of NAD(P)H-oxidase on the surface of viable cells with trans-membrane NADH-oxidoreductase, measured with WST-1 in the presence of 1-methoxy PMS, showed that cell-surface NAD(P)H-oxidase was differentially inhibited by the cell-impermeable thiol-blocking agent pCMBS, but was unaffected or stimulated by other thiol blocking agents. Capsaicin, which inhibits trans-plasma membrane NADH-oxidoreductase activity, stimulated surface NAD(P)H-oxidase. Metabolic inhibitors had little effect on surface NAD(P)H-oxidase activity but inhibited trans-plasma membrane activity. These results do not support the view the surface NAD(P)H-oxidase is a terminal oxidase for trans-plasma membrane NADH-oxidoreductase.
机译：哺乳动物细胞的表面面临着氧化环境，该环境可能会破坏其所暴露的蛋白质，脂质和碳水化合物。相反，细胞质在减少，其氧化还原状态受到严格调节。将电子从胞质NADH转移到外部电子受体（如氧气）的跨质膜氧化还原酶广泛参与细胞氧化还原控制。它们将氧气还原为水，并可能产生活性氧，例如超氧化物和过氧化氢。另外，已经证明完整细胞上外部NAD（P）H-氧化酶和作为洗脱蛋白，但是跨质膜NADH-氧化还原酶和细胞表面NAD（P）H-氧化酶之间的关系尚不清楚。为了进一步研究质膜NAD（P）H-氧化还原酶之间的关系，并深入了解这些氧化还原活性膜蛋白的生理功能，我们采用了一种简单的比色测定法来测量跨膜NAD（P）H-氧化还原酶的活性。活细胞实时测量细胞表面的NAD（P）H-氧化酶。在NADH或NADPH存在下，使用细胞不可渗透的四唑盐WST-1，但是在没有中间电子受体的情况下，我们显示细胞表面NAD（P）H-氧化酶在哺乳动物细胞上广泛表达，并且在快速增殖的细胞上比在静止的中性粒细胞和脾细胞上丰富。 NAD（P）H-氧化酶的辅因子依赖性比率（NADH：NADPH）在不同细胞之间差异很大（0.7-5.2），这表明细胞表面氧化酶家族或这些酶的活性可以多种方式调节。在1-甲氧基PMS存在下，用WST-1测定的活细胞表面NAD（P）H-氧化酶与跨膜NADH-氧化还原酶的比较表明，细胞表面NAD（P）H-氧化酶为被细胞不可渗透的硫醇封闭剂pCMBS差异抑制，但不受其他硫醇封闭剂的影响或刺激。辣椒素抑制跨膜NADH-氧化还原酶的活性，刺激表面NAD（P）H-氧化酶。代谢抑制剂对表面NAD（P）H-氧化酶活性影响很小，但抑制了跨质膜活性。这些结果不支持以下观点：表面NAD（P）H-氧化酶是跨质膜NADH-氧化还原酶的末端氧化酶。

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