کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1926659 | 1536474 | 2008 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: 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+](/preview/png/1926659.png)
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 (SERCA) 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.
Journal: Archives of Biochemistry and Biophysics - Volume 476, Issue 1, 1 August 2008, Pages 87–94