diff --git a/README.md b/README.md new file mode 100644 index 0000000..e34f428 --- /dev/null +++ b/README.md @@ -0,0 +1,40 @@ +# Readme for the Model Associated with the Papers + +1. Moczydlowski & Latorre Gating kinetics of Ca++-activated K+ channels from rat muscle incorporated into planar lipid bilayers. *J Gen Physiol* 1983;82:511-542. +2. Wang et al., Riluzole-induced block of voltage-gated Na(+) current and activation of BK(Ca) channels in cultured differentiated human skeletal muscle cells. *Life Sci* 2008;82:11-20. + +## Abstract + +The gating kinetics of a Ca2+-activated K+ channel from adult rat muscle plasma membrane are studied in artificial planar bilayers. Analysis of single-channel fluctuations distinguishes two Ca2+- and voltage-dependent processes: + +- (a) short-lived channel closure (less than 1 ms) events appearing in a bursting pattern; +- (b) opening and closing events ranging from one to several hundred milliseconds in duration. + +The latter process is studied independently of the first and is denoted as the primary gating mode. At constant voltage, the mean open time of the primary gating mode is a linear function of the [Ca2+], whereas the mean closed time is a linear function of the reciprocal [Ca2+]. In the limits of zero and infinite [Ca2+], the mean open and the mean closed times are, respectively, independent of voltage. These results are predicted by a kinetic scheme consisting of the following reaction steps: + +- (a) binding of Ca2+ to a closed state; +- (b) channel opening; +- (c) binding of a second Ca2+ ion. + +In this scheme, the two Ca2+ binding reactions are voltage dependent, whereas the open-closed transition is voltage independent. The kinetic constant derived for this scheme gives an accurate theoretical fit to the observed equilibrium open-state probability. The results provide evidence for a novel regulatory mechanism for the activity of an ion channel: modulation by voltage of the binding of an agonist molecule, in this case, Ca2+ ion. + +## To run the model + +Expand the archive and cd into the newly created directory and run: +`xppaut Ikca.ode` +then click on **Initialcond** -> **Go** + +The trace from voltage-clamp simulation of 'cagk.mod' in NEURON was reproduced: + +![ikca.jpg](./ikca.jpg) + +## The model file was supplied by + +Dr. Sheng-Nan Wu +National Cheng Kung University Medical College +Tainan 70101, Taiwan +snwu@mail.ncku.edu.tw + +--- + +2025-05-30: Standardized to Markdown. diff --git a/readme.html b/readme.html deleted file mode 100644 index a8c5d3f..0000000 --- a/readme.html +++ /dev/null @@ -1,51 +0,0 @@ -
-This is the readme for the model associated with the papers:
-
-1. Moczydlowski & Latorre Gating kinetics of Ca++-activated K+
-    channels from rat muscle incorporated into planar lipid
-    bilayers. J Gen Physiol 1983;82:511-542.
-2. Wang et a., Riluzole-induced block of voltage-gated Na(+) current
-    and activation of BK(Ca) channels in cultured differentiated human
-    skeletal muscle cells. Life Sci 2008;82:11-20.
-
-Abstract:
-
-The gating kinetics of a Ca2+-activated K+ channel from adult rat
-muscle plasma membrane are studied in artificial planar
-bilayers. Analysis of single-channel fluctuations distinguishes two
-Ca2+- and voltage-dependent processes: (a) short-lived channel closure
-(less than 1 ms) events appearing in a bursting pattern; (b) opening
-and closing events ranging from one to several hundred milliseconds in
-duration. The latter process is studied independently of the first and
-is denoted as the primary gating mode. At constant voltage, the mean
-open time of the primary gating mode is a linear function of the
-[Ca2+], whereas the mean closed time is a linear function of the
-reciprocal [Ca2+]. In the limits of zero and infinite [Ca2+], the mean
-open and the mean closed times are, respectively, independent of
-voltage. These results are predicted by a kinetic scheme consisting of
-the following reaction steps: (a) binding of Ca2+ to a closed state;
-(b) channel opening; (c) binding of a second Ca2+ ion. In this scheme,
-the two Ca2+ binding reactions are voltage dependent, whereas the
-open-closed transition is voltage independent. The kinetic constant
-derived for this scheme gives an accurate theoretical fit to the
-observed equilibrium open-state probability. The results provide
-evidence for a novel regulatory mechanism for the activity of an ion
-channel: modulation by voltage of the binding of an agonist molecule,
-in this case, Ca2+ ion.
-
-To run the model:
-Expand the archive and cd into the newly created directory and run:
-xppaut Ikca.ode
-then click on Initialcond -> Go
-The trace from voltage-clamp simulation of 'cagk.mod' in NEURON was
-reproduced:
-
-ikca.jpg
-
-The model file was supplied by:
-
-Dr. Sheng-Nan Wu
-National Cheng Kung University Medical College
-Tainan 70101, Taiwan
-snwu@mail.ncku.edu.tw
-