Probing the Potassium Channel Inhibitor Binding Site

探测钾通道抑制剂结合位点

• 批准号: 7060034
• 负责人: Sarah J. YOHANNAN
• 金额: $ 4.88万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2007-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060034
• 关键词: Escherichia coli; X ray crystallography; binding sites; crystallization; electrophysiology; ion channel blocker; long QT syndrome; membrane model; membrane proteins; model design /development; pharmacokinetics; postdoctoral investigator; potassium channel; protein binding; protein structure function; site directed mutagenesis; transfection /expression vector; voltage gated channel; yeasts

DESCRIPTION (provided by applicant): Potassium channels contain a conserved ion conduction pore that contains a promiscuous ligand binding site able to bind a multitude of drugs. Determining the precise location of the site, and the mechanism by which binding occurs has been elusive. Small sequence differences in the channels affect hydrophobicity, aromaticity, cavity size, and channel gating which are all thought to affect ligand binding affinity. KcsA, the bacterial channel of known structure, is a suitable model for studying the pore region of the family of potassium channels due to the relative ease with which it can be mutated, highly expressed, and crystallized, I propose to establish a system using the KcsA potassium channel to study the features of the channel cavity using mutagenesis along with both structural biology and electrophysiology methods. I will also express and crystallize HERG (human ether-a-go-go-related gene), a potassium channel present in heart muscle cells. HERG is of particular interest because many common drugs block its channel causing loss of function, which results in an abnormal electrical signal (long-QT syndrome) that can lead to the arrythmia Torsades de Pointes and sometimes sudden heart failure.

描述（由申请人提供）： 钾通道包含一个保守的离子传导孔，其中包含一个能够结合多种药物的混杂配体结合位点。 确定该位点的精确位置以及发生结合的机制一直难以捉摸。 通道中的微小序列差异会影响疏水性、芳香性、空腔大小和通道门控，这些都被认为会影响配体结合亲和力。 KcsA是已知结构的细菌通道，由于其相对容易突变、高表达和结晶，是研究钾通道家族孔区域的合适模型，我建议建立一个使用KcsA钾通道的系统，通过诱变以及结构生物学和电生理学方法来研究通道腔的特征。 我还将表达并结晶 HERG（人类 ether-a-go-go 相关基因），这是一种存在于心肌细胞中的钾通道。 HERG 特别令人感兴趣，因为许多常见药物会阻断其通道，导致功能丧失，从而导致异常电信号（长 QT 综合征），从而导致心律失常、尖端扭转型室性心动过速，有时甚至导致突发心力衰竭。