• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Life sciences >Inhibition of microsomal ATPases by high concentration of Mg2+ in tracheal epithelial cells.
【24h】

Inhibition of microsomal ATPases by high concentration of Mg2+ in tracheal epithelial cells.

机译：气管上皮细胞中高浓度的Mg2 +对微粒体ATPase的抑制作用。

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

Previous work in our laboratory established the presence of two types of microsomal ATPases, a low-affinity vanadate-sensitive (LAVS) and a high-affinity vanadate-sensitive (HAVS) ATPases, in tracheal epithelial cells. These ATPases were identified as Ca2+-ATPases by specific inhibitors and microsomal Ca2+ uptakes. Since the regulatory roles of Mg2+ on both cellular Ca2+-signaling and epithelial transports were demonstrated, the effects of Mg2+ on these ATPases were investigated. Mg2+-dependence of ATPase activity appeared bell-shaped with a maximal activity at 1-2 mM Mg2+ and Mg2+ at higher than 2 mM inhibited these enzymes. In a kinetic analysis of the LAVS ATPase inhibition, high concentration of Mg2+ appeared to inhibit the binding of ATP to a substrate-binding site. The microsomal 45Ca2+ uptakes mediated by both ATPases were also inhibited by high concentration of Mg2+. In order to test whether high concentration of Mg2+ directly inhibits these enzymes, microsomes were made leaky by the treatment of Triton X-100 and the microsomal ATPases were solubilized with CHAPS. The leaky microsomal ATPases and CHAPS-solubilized ATPases were similarly inhibited by high concentration of Mg2+, suggesting that Mg2+ directly inhibit these enzymes. In conclusion, Mg2+ has two types of modulatory effects on these enzymes, a catalytic effect at low concentration and an inhibitory effect at high concentration.
机译：我们实验室先前的工作确定了气管上皮细胞中存在两种类型的微粒体ATPase，即低亲和力钒酸盐敏感性（LAVS）和高亲和力钒酸盐敏感性（HAVS）ATPase。这些ATP酶通过特异性抑制剂和微粒体对Ca2 +的吸收被鉴定为Ca2 + -ATPase。由于证明了Mg2 +在细胞Ca2 +信号传导和上皮运输中的调节作用，因此研究了Mg2 +对这些ATPase的作用。 Mg2 +依赖于ATPase活性呈钟形，最大活性在1-2 mM时Mg2 +和高于2 mM的Mg2 +抑制了这些酶。在LAVS ATPase抑制的动力学分析中，高浓度的Mg2 +似乎抑制了ATP与底物结合位点的结合。两种ATP酶介导的微粒体45Ca2 +的摄取也被高浓度的Mg2 +抑制。为了测试高浓度的Mg2 +是否直接抑制了这些酶，通过Triton X-100处理使微粒体渗漏，并用CHAPS溶解了微粒体ATPase。泄漏的微粒体ATPase和CHAPS增溶的ATPase同样受到高浓度Mg2 +的抑制，这表明Mg2 +直接抑制了这些酶。总之，Mg2 +对这些酶具有两种调节作用，即低浓度时的催化作用和高浓度时的抑制作用。

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