On ionic conduction in potassium channels

In ref. 1, we presented an alternative mechanism for conduc- tion of K+ in K+ channels where site vacancies are involved, and we proposed that coexistence of several ion permeation mechanisms is energetically possible. Specifically, we found that conduction can be described as a more anarchic phe- nomenon than previously habitually characterized by the con- certed translocations of K+-water-K+. This alternative pathway entails the possible presence of vacancies, with neither K+ nor water molecules in certain sites; sometimes, ions can even be found at adjacent binding sites. Moreover, we sug- gested that this mechanism is likely to be just one example among a plethora of alternative configurations and conduction pathways that ions and water may adopt during permeation, and that it can be viewed as a perturbation to the long- standing accepted mechanism involving neat, organized ion–water fluxes