Calcium-sensitive inactivation in the gating of single calcium channels.
Voltage-activated calcium channels open and close, or gate, according to molecular transition rates that are regulated by transmembrane voltage and neurotransmitters. Here evidence for the control of gating by calcium was found in electrophysiological records of single, L-type calcium channels in heart cells. Conditional open probability analysis revealed that calcium entry during the opening of a single channel produces alterations in gating transition rates that evolve over the course of hundreds of milliseconds. Such alteration of calcium-channel gating by entry of a favored permeant ion provides a mechanism for the short-term modulation of single-ion channels.
Yue
D T
DT
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Backx
P H
PH
Imredy
J P
JP
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000187:drug effects; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D011336:Probability; D016276:Ventricular Function
D015220:Calcium Channels; D015124:8-Bromo Cyclic Adenosine Monophosphate; D002118:Calcium