•  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
期刊检索


检索
检索项:
检索词:
总目录
  • WCSB9︱2019(第九届)世界采样和混样大会 查看全文>>
  • 关于召开第十五届全国青年分析测试学术报告会的通知 查看全文>>
友情链接
组氨酸激酶HK853酸碱调控机制的NMR研究
    点此下载全文
作者单位
吉仕夏,刘乙祥,姜红鹰,李从刚,姜凌,刘买利 1.中国科学院生物磁共振重点实验室波谱与原子分子物理国家重点实验室武汉磁共振中心(中国科学院武汉物理与数学研究所)2.中国科学院大学 
基金项目:国家自然科学基金资助项目(21735007,21573280,21603268)
中文摘要:双组分信号转导系统是细菌应对外界刺激和调控自身生理活动的重要系统。组氨酸激酶是双组分信号转导系统的重要组成部分,大多数组氨酸激酶具有多功能性,不仅能自身磷酸化并能把磷酸基团传递给应激调节蛋白(Response regulator,RR)使之磷酸化,还能催化RR的去磷酸化。研究发现组氨酸激酶HK853的功能受pH值调控,该文利用选择性同位素标记方法,通过NMR技术研究了参与HK853与RR468相互作用的关键氨基酸位点。发现DHp结构域His260侧链的pKa值与HK853的磷酸酶活性有很好的对应关系,HK853与底物形成复合物后其pKa值降低,使His260侧链更易于去质子化,有助于HK853磷酸酶活性的提高。阐明了HK853行使磷酸酶功能时的酸碱调控机制。
中文关键词:核磁共振  选择性同位素标记  双组分信号转导系统  磷酸化  组氨酸激酶
 
Investigation on pH Regulatory Mechanism of HK853 by NMR Spectroscopy
Abstract:A two-component signal transduction system is the most important signal transduction system for bacteria to cope with external stimuli and self regulate physiological activities.Histidine kinase is an important component of the two-component signal transduction system.Most histidine kinases are multifunctional,they could autophosphorylate and then deliver phosphate groups to the cognate response regulators(RR),and they could also catalyze the dephosphorylation of the response regulator proteins.It is found that the dephosphorylation activity of histidine kinase HK853 is pH dependent.The pH regulation mechanism of HK853 is investigated by using selectively isotopic labeling and NMR spectroscopy.It is revealed that the pKa value of His260 side chain involved in the interaction has a good relationship with the pH dependent phosphatase activity of HK853,which will decrease after HK853 forms a complex with the substrate.The deprotonated imidazole ring plays an important role in the catalytic reaction.This change contributes to the enhancement of HK853 phosphatase activity,ensures the efficiency of acid-base regulation and clarifies the acid-base regulation mechanism of HK853 when performing phosphatase function.
Key Words:NMR  site-selective labeling  two-component signal transduction system  phosphorylation  histidine kinase
引用本文:吉仕夏,刘乙祥,姜红鹰,李从刚,姜凌,刘买利.组氨酸激酶HK853酸碱调控机制的NMR研究[J].分析测试学报,2019,(5):503-509.
摘要点击次数: 201
全文下载次数: 332
查看全文  查看/发表评论  下载PDF阅读器