...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Extremophiles: Life under extreme conditions >Biochemical characterization of two glutamate dehydrogenases with different cofactor specificities from a hyperthermophilic archaeon Pyrobaculum calidifontis
【24h】

Biochemical characterization of two glutamate dehydrogenases with different cofactor specificities from a hyperthermophilic archaeon Pyrobaculum calidifontis

机译：嗜热古细菌Pyrobaculum calidifontis中两种具有不同辅因子特异性的谷氨酸脱氢酶的生化特性

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

Two putative glutamate dehydrogenase (GDH) genes (pcal_1031 and pcal_1606) were found in a sulfur-dependent hyperthermophilic archaeon, Pyrobaculum calidifontis. The two genes were then expressed in Escherichia coli, and both of the recombinant gene products showed GDH activity. The two enzymes were then purified to homogeneity and characterized in detail. Although both purified GDHs had a hexameric structure and neither exhibited allosteric regulation, they showed different coenzyme specificities: one was specific for NAD~+, the other for NADP~+ and different heat activation mechanisms. In addition, there was little difference in the kinetic constants, optimal temperature, thermal stability, optimal pH and pH stability between the two enzymes. The overall sequence identity between the two proteins was very high (81 %), but was not high in the region recognizing the 2′ position of the adenine ribose moiety, which is responsible for coenzyme specificity. This is the first report on the identification of two GDHs with different coenzyme specificities from a single hyperthermophilic archaeon and the definition of their basic in vitro properties.
机译：在硫依赖的超嗜热古细菌Pyrobaculum calidifontis中发现了两个推定的谷氨酸脱氢酶（GDH）基因（pcal_1031和pcal_1606）。然后，这两个基因在大肠杆菌中表达，并且两个重组基因产物均显示GDH活性。然后将这两种酶纯化至均质并进行详细表征。尽管两种纯化的GDHs均具有六聚体结构，且均不表现出变构调控，但它们显示出不同的辅酶特异性：一种对NAD〜+具有特异性，另一种对NADP〜+具有特定的热激活机制。另外，两种酶之间的动力学常数，最佳温度，热稳定性，最佳pH和pH稳定性几乎没有差异。两种蛋白质之间的整体序列同一性非常高（81％），但在识别负责辅酶特异性的腺嘌呤核糖部分2'位置的区域中并不很高。这是关于从单个超嗜热古细菌中鉴定具有不同辅酶特异性的两种GDH的首次报道，以及它们的基本体外特性的定义。

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