The selectivity filter in potassium (K+) channels is a highly regulated and complex functional module. It is able to discriminate between different cation species and the same time forms a physiological gate in a number of different channels. The molecular mechanics of this gate are currently not well understood.

In this project, we investigate selectivity filter gating in the model system of viral Kcv channels. The proteins are expressed in vitro and single-channel recordings are performed in planar lipid bilayers. The sub-millisecond kinetics of the filter gate are quantified. with extended beta distribution analysis. Via point mutations and different ions, we probe and manipulate the kinetics of this gate to identify the underlying molecular mechanisms.