Allosteric modulation of ion channels: the case of maxi-K.

Maxi-K channel gating is modulated by both membrane voltage and cytoplasmic Ca2+. Recent work has led to a quantitative understanding of this dual regulatory mechanism, derived from classical allosteric principles, in terms of the energetic coupling among membrane voltage, Ca2+ binding, and opening of the channel's gate. Our new understanding of the gating pathway can be applied to the interpretation of mutagenesis experiments and may serve as an example in the analysis of other dually regulated signaling molecules.