LOCALIZATION OF LIGAND INTERACTIONS WITH THE SODIUM PUMP

描述（申请人的摘要）：这项工作的目的是获得一个 更完整地了解钠泵蛋白或Na，K-ATP酶 进行其基本的生理作用，钠和钾的主动运输 离子穿过细胞质膜。过去的实验研究 几十年来，已经建立了运输反应之间的关系， 这种内在膜蛋白介导的生物化学反应 与运输有关。该蛋白质将钠和钾的转运偶联到 ATP的水解以及这种偶联是如何实现的， 运输生理学已经确定， 负责阳离子转运和ATP结合及水解的蛋白质。 我们已经提出，构象耦合发生在这两个 将进行的领域和实验将检验这一提议。具体 关于蛋白质各部分的运动， 目前的工作计划将测试这些建议，所使用的方法将 联合收割机在昆虫细胞中异源表达绵羊肾Na，K-ATP酶， 通常不具有这种蛋白质，与蛋白质化学一起， 荧光标记这些研究还将试图解释 在主动运输过程中的β亚基。钠泵至关重要 在各种器官中的体液和电解质平衡和兴奋性， 是洋地黄的特异性靶点，洋地黄是心脏病中最广泛使用的治疗药物。 不足在充分描述病理状态之前 包括体液和电解质失衡或了解洋地黄 作品可以实现，我们需要有一个充分的描述， 功能正常的钠泵进行的研究旨在提供 这样的描述。对Na，K-ATP酶作用机制的了解将有助于进一步研究Na，K-ATP酶的作用机制。 也是非常宝贵的会计机制的其他成员的 P型ATP酶超家族。

DESCRIPTION (Applicant's abstract): The objective of this work is to obtain a more complete understanding of how the sodium pump protein or Na,K-ATPase carries out its essential physiological role, the active transport of Na and K ions across the cellular plasma membrane. Experimental studies over the past several decades have established relationships between the transport reactions which this intrinsic membrane protein mediates and the biochemical reactions associated with the transport. The protein couples the transport of Na and K to the hydrolysis of ATP and how this coupling is achieved is a central issue in transport physiology. It has been established that there are separate regions of the protein responsible for cation transport and ATP binding and hydrolysis. We have proposed that a conformational coupling occurs between these two domains and experiments to be carried out will test this proposal. Specific postulates have been made about movements in the various parts of the protein and the present program of work will test these proposals The methods used will combine heterologous expression of the sheep renal Na,K-ATPase in insect cells, which do not usually possess this protein, together with protein chemistry and fluorescent labelling. The studies will also seek to explain the precise role of the beta-subunit in the active transport process. The sodium pump is vital in a variety of organs for fluid and electrolyte balance and excitability, and is the specific target of digitalis, the most widely used therapy in cardiac insufficiency. Before an adequate description of the pathological states involving fluid and electrolyte imbalance or an understanding of how digitalis works can be achieved we need to have an adequate description of the functioning sodium pump. The studies to be carried out are aimed at providing such a description. An understanding of the mechanism of the Na,K-ATpase will also be invaluable in accounting for the mechanism of the other members of the P-type ATPase superfamily.