Ion Channel Reconstitution

An introduction to the methods available for ion channel reconstitution

Reconstitution describes the disassembly of a complex structure; the isolation of one or more of the components of that system and the reassembly of these components into an intelligible, measurable system. When applied to membrane proteins, such as ion-channels, it describes the solubilisation of the membrane, the isolation of the channel protein from the other membrane constituents and the re...

Ion channel activity drives ion channel expression.

K+-conducting ion channel of the chloroplast inner envelope: functional reconstitution into liposomes.

Potassium flux between the chloroplast stroma and cytoplasm is known to be indirectly linked to H+ countertransport and, hence, stromal pH and photosynthetic capacity. The specific molecular mechanism that facilitates K+ flux across the chloroplast envelope is not known and has been a source of controversy for well over a decade. The objective of this study was to elucidate the nature of this e...

Functional Reconstitution of a Prokaryotic K+ Channel

SliK, a K+ channel encoded by the Streptomyces KcsA gene, was expressed, purified, and reconstituted in liposomes. A concentrative 86Rb+ flux assay was used to assess the ion transport properties of SliK. SliK-mediated ionic flux shows strong selectivity for K+ over Na+ and is inhibited by micromolar concentrations of Ba2+, mirroring the basic permeation characteristic of eukaryotic K+ channels...

Reconstitution of a chloroplast protein import channel.

The chloroplastic outer envelope protein OEP75 with a molecular weight of 75 kDa probably forms the central pore of the protein import machinery of the outer chloroplastic membrane. Patch-clamp analysis shows that heterologously expressed, purified and reconstituted OEP75 constitutes a voltage-gated ion channel with a unit conductance of Lambda = 145pS. Activation of the OEP75 channel in vitro ...