%0 Journal Article %1 Dura_2003_571 %A Dura, M. %A Zahradn�k, I. %A Zahradn�kov�, A. %D 2003 %J Physiol. Res. %K Animals; Bilayers; Calcium Calcium; Channel Channel; Computer Computer-Assisted Dogs; Electrophysiology; Gating; Heart; Ion Kinetics; Lipid Microsomes; Patch-Clamp Phosphatidylcholines; Phosphatidylethanolamines; Processing, Receptor Release Reticulum; Ryanodine Sarcoplasmic Signal Simulation; Techniques; %N 5 %P 571--578 %T Kinetics of cardiac RyR channel gating studied at high temporal resolution. %V 52 %X 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 Ca$^2+$ 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 Ca$^2+$ ions to open.

@article{Dura_2003_571, abstract = {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 {C}a$^{2+}$ 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 {C}a$^{2+}$ ions to open.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {Dura, M. and Zahradn�k, I. and Zahradn�kov�, A.}, biburl = {https://www.bibsonomy.org/bibtex/29ec1cdee2c452ff694051f2fe4526fcf/hake}, description = {The whole bibliography file I use.}, file = {Dura_2003_571.pdf:Dura_2003_571.pdf:PDF;Dura_2003_571.pdf:Dura_2003_571.pdf:PDF}, institution = {Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vl�rska 5, 833 34 Bratislava, Slovak Republic.}, interhash = {cc6c3397ef23d84d829d466fced57fce}, intrahash = {9ec1cdee2c452ff694051f2fe4526fcf}, journal = {Physiol. Res.}, keywords = {Animals; Bilayers; Calcium Calcium; Channel Channel; Computer Computer-Assisted Dogs; Electrophysiology; Gating; Heart; Ion Kinetics; Lipid Microsomes; Patch-Clamp Phosphatidylcholines; Phosphatidylethanolamines; Processing, Receptor Release Reticulum; Ryanodine Sarcoplasmic Signal Simulation; Techniques;}, number = 5, pages = {571--578}, pmid = {14535832}, timestamp = {2009-06-03T11:21:10.000+0200}, title = {Kinetics of cardiac RyR channel gating studied at high temporal resolution.}, volume = 52, year = 2003 }