Quantitative relationship between the protein secondary structure in cardiac sarcolemma and the activity of the membrane-bound Ca2+-ATPase.
نویسندگان
چکیده
In the absence of ATP, increasing concentrations of calcium within a range between 0.1--8.0 mmol . 1(-1) gradually lowered the alpha-helix content of proteins in rat heart sarcolemma requiring no energy supply. In the presence of ATP, similar concentrations of calcium stepwise activated the sarcolemmal low-affinity Ca2+-ATPase. A mathematical analysis of the data obtained revealed a quantitative relationship between calcium-induced stimulation of the Ca2+-ATPase activity and a diminution of the alpha-helix contents of membrane proteins in cardiac sarcolemma. The cooperation between changes in protein conformation and energy consumption in relation to the supposed role of low-affinity Ca2+-ATPase in gating the calcium channel are discussed.
منابع مشابه
Effect of calcium on the structure-function relationship of (Na+ + K+)-ATPase in cardiac sarcolemma.
Calcium-induced changes in (Na+ + K+)-ATPase activity and structural changes of membrane bound proteins in rat heart sarcolemma were investigated. Increasing concentrations of Ca2+ (0.1-8.0 mmol.l-1) gradually inhibited the (Na+ + K+)-ATPase activity and decreased the alpha-helix content of sarcolemmal proteins. Mathematical and graphical analysis of observed data yielded a quantitative relatio...
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عنوان ژورنال:
- General physiology and biophysics
دوره 4 4 شماره
صفحات -
تاریخ انتشار 1985