We have characterized the K$^+$ channel of canine cardiac sarcoplasmic
reticulum in terms of its gating kinetics and conductance states.
We demonstrate that the open channel dwells in two states, O1 and
O2, where O1 is a true subconductance state of O2. The two open states
are linked with a closed state by a cyclic gating scheme. Under certain
circumstances, however, important information can be derived using
a binary model. Each open state separately exhibited an ohmic current-voltage
relation with unitary conductance values of 105 (O1) and 189 (O2)
pS in 0.1 M K$^+$. Gating between closed and open states was
weakly voltage dependent, and we derive reaction rate constants for
the state transitions. Finally, we postulate three models to explain
the existence of a subconductance state (blockade, stenosis, flutter).
We argue that a flutter model best accounts for our observations
of O1.
%0 Journal Article
%1 Hill_1990_H159
%A Hill, J. A.
%A Coronado, R.
%A Strauss, H. C.
%D 1990
%J Am. J. Physiol.
%K 2301604 Animals, Cardiovascular, Channel Channels, Conductivity, Electric Gating, Gov't, Ion Kinetics, Models, Myocardium, Non-U.S. P.H.S., Potassium Research Reticulum, Sarcoplasmic Support, U.S.
%N 1 Pt 2
%P H159--H164
%T Open-channel subconductance state of K$^+$ channel from cardiac
sarcoplasmic reticulum.
%V 258
%X We have characterized the K$^+$ channel of canine cardiac sarcoplasmic
reticulum in terms of its gating kinetics and conductance states.
We demonstrate that the open channel dwells in two states, O1 and
O2, where O1 is a true subconductance state of O2. The two open states
are linked with a closed state by a cyclic gating scheme. Under certain
circumstances, however, important information can be derived using
a binary model. Each open state separately exhibited an ohmic current-voltage
relation with unitary conductance values of 105 (O1) and 189 (O2)
pS in 0.1 M K$^+$. Gating between closed and open states was
weakly voltage dependent, and we derive reaction rate constants for
the state transitions. Finally, we postulate three models to explain
the existence of a subconductance state (blockade, stenosis, flutter).
We argue that a flutter model best accounts for our observations
of O1.
@article{Hill_1990_H159,
abstract = {We have characterized the {K}$^{+}$ channel of canine cardiac sarcoplasmic
reticulum in terms of its gating kinetics and conductance states.
We demonstrate that the open channel dwells in two states, O1 and
O2, where O1 is a true subconductance state of O2. The two open states
are linked with a closed state by a cyclic gating scheme. Under certain
circumstances, however, important information can be derived using
a binary model. Each open state separately exhibited an ohmic current-voltage
relation with unitary conductance values of 105 (O1) and 189 (O2)
pS in 0.1 M {K}$^{+}$. Gating between closed and open states was
weakly voltage dependent, and we derive reaction rate constants for
the state transitions. Finally, we postulate three models to explain
the existence of a subconductance state (blockade, stenosis, flutter).
We argue that a flutter model best accounts for our observations
of O1.},
added-at = {2009-06-03T11:20:58.000+0200},
author = {Hill, J. A. and Coronado, R. and Strauss, H. C.},
biburl = {https://www.bibsonomy.org/bibtex/23348c12b56db63e86b81aa469c14d81e/hake},
description = {The whole bibliography file I use.},
file = {Hill_1990_H159.pdf:Hill_1990_H159.pdf:PDF},
interhash = {582bdc79fc783bc47796f9c5966c1348},
intrahash = {3348c12b56db63e86b81aa469c14d81e},
journal = {Am. J. Physiol.},
key = 210,
keywords = {2301604 Animals, Cardiovascular, Channel Channels, Conductivity, Electric Gating, Gov't, Ion Kinetics, Models, Myocardium, Non-U.S. P.H.S., Potassium Research Reticulum, Sarcoplasmic Support, U.S.},
month = Jan,
number = {1 Pt 2},
pages = {H159--H164},
pmid = {2301604},
timestamp = {2009-06-03T11:21:14.000+0200},
title = {Open-channel subconductance state of {K}$^{+}$ channel from cardiac
sarcoplasmic reticulum.},
volume = 258,
year = 1990
}