Kinetic characteristics of interaction of conotoxin with N-type Ca2+ channels in rat hippocampal neurons
The binding and unbinding constants describing interaction of ω-CTx-GVIA with N-type Ca2+ channels were calculated based on the time course of the blocking action of the toxin. The experiments were carried out on pyramidal neurons freshly dissociated from theCA3 region of the rat hippocampus using a “concentration-clamp” technique and a patch-clamp technique in the whole-cell configuration. The bindingk 1 and unbindingk −1 constants were evaluated as 0.32 (μM·sec)−1 and 0.004 sec−1, respectively. The dissociation constantK D kinetically derived from the ratiok −1/k 1 was 0.012 μM. These values allow us to interpret the apparent “irreversibility” of the toxin action.
KeywordsGlobal Cerebral Ischemia Peripheral Neuron Simple Kinetic Model Toxin Molecule Chick Sensory Neurone
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