[Cooperative phenomena in the activity of single ion channels].
Using the patch-voltage-clamp method kinetics of the fast potential-dependent K+-channels in molluscan neurones was investigated. It was found that under given experimental conditions the amplitudes of single current impulses have a wide spectrum. The amplitudes are proportional to a number of the current substates involved. Averaged fronts of the current impulses are S-shaped, and have duration greater than 1 ms. Averaged duration of the current impulses increases (from 0.25 to 30-40 ms) with the impulse amplitude (or with the number of the substates involved). There is a sharp bend of the dependence at the impulse amplitude 0.6-0.7 of maximal value. The phenomena investigated reflect, probably, cooperativity of the channel transitions between the substates. The degree of the cooperativity depends on the membrane potential value.
Geletiuk
V I
VI
Kazachenko
V N
VN
D000818:Animals; D007700:Kinetics; D008564:Membrane Potentials; D008974:Mollusca; D009474:Neurons / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology*
D015221:Potassium Channels
Kooperativnye iavleniia v aktivnosti odinochnykh ionnykh kanalov.