Kinetics of cardiac RyR channel gating studied at high temporal resolution.
Kinetics of cardiac RyR channel gating studied at high temporal resolution.
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DOI：
10.33549/physiolres.930381
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发表时间：
2003
影响因子：
2.1
通讯作者：
Miroslav Dura;I. Zahradník;A. Zahradníková
中科院分区：
文献类型：
--
作者：
Miroslav Dura;I. Zahradník;A. Zahradníková
Measurements of ryanodine receptor (RyR) activity during dynamic changes of calcium concentration have suggested that RyR has at least four calcium binding sites, and that activation transpires as an increase in the activity within the high open probability H-mode. Binding of several Ca2+ ions within the H-mode should manifest itself in the steady-state RyR activity by the presence of multiple closed times. However, previously only two closed times were detected in the H-mode of RyR activity. Here we recorded steady-state activity of single cardiac RyRs with high temporal resolution and compared it to data simulated under the same conditions using our previously published model of RyR gating. At a 10 kHz resolution, the closed time histograms of both experimental and simulated data had three exponential components. The closed times of simulated data were not significantly different from those obtained experimentally. After filtering at 2 kHz, only two exponential closed time components with time constants not significantly different from those previously published could be detected in both experimental and simulated records. The conformity of the steady-state experimental data to the model derived from the dynamic data provides further support for the idea that RyRs need binding of multiple Ca2+ ions to open.
