Specificity of ligand binding to transport sites: Ca2+ binding to the Ca2+ transport ATPase and its dependence on H+ and Mg2+.
Specificity of ligand binding to transport sites: Ca2+ binding to the Ca2+ transport ATPase and its dependence on H+ and Mg2+.
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配体与转运位点结合的特异性：Ca2 与 Ca2 转运 ATP 酶的结合及其对 H 和 Mg2 的依赖性。
DOI：
10.1016/j.abb.2008.04.035
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发表时间：
2008
影响因子：
3.9
通讯作者：
Inesi,G
中科院分区：
文献类型：
--
作者：
Zafar,Sufi;Hussain,Arif;Liu,Yueyong;Lewis,David;Inesi,G
配体与转运位点的结合是转运atp酶催化循环的第一步。在这里，我们考虑了肌浆网Ca2+ atp酶（SERCA1）的良好表征，并描述了一系列Ca2+结合等温线，通过平衡测量在各种H+和Mg2+浓度的存在。我们使用基于最少机械步骤的模型对等温线进行统计力学分析。分析允许令人满意的配合，并产生在各种条件下特定Ca2+位置的占用信息。它还为分析平衡条件下导致紧密耦合催化活化的转运位点的结合特异性提供了一种基本方法。
Ligand binding to transport sites constitutes the initial step in the catalytic cycle of transport ATPases. Here, we consider the well characterized Ca2+ATPase of sarcoplasmic reticulum (SERCA1) and describe a series of Ca2+binding isotherms obtained by equilibrium measurements in the presence of various H+and Mg2+concentrations. We subject the isotherms to statistical mechanics analysis, using a model based on a minimal number of mechanistic steps. The analysis allows satisfactory fits and yields information on occupancy of the specific Ca2+sites under various conditions. It also provides a fundamental method for analysis of binding specificity to transport sites under equilibrium conditions that lead to tightly coupled catalytic activation.