KcsA - Prokaryotic pH-gated Potassium Channel
Family:
Prokaryotic Tetrameric Potassium Channels
Topology:
The channel protein contains two transmembrane helices (M1 and M2). The channel itself is a tetramer composed of four identical subunits so that the M2 helix faces the central pore, while the other M1 helix faces the lipid membrane.
History and function:
KcsA was the first potassium ion channel to be characterized using x-ray crystallography by Roderick MacKinnon and his colleagues in 1998. As one of the most studied ion channels to this day, KcsA is a template for research on K+ channel function. The KcsA channel is considered a model channel because its structure provides a framework for understanding K+ channel conduction, which has three parts: Potassium selectivity, channel gating by pH sensitivity, and voltage-gated channel inactivation.
Data and Applications
KcsA - Single Channel Recordings
Orbit 16 and applications:
Data were kindly provided by Ionera.
Single channel currents of tetrameric potassium channel KcsA E71A recorded from 5 selected bilayers in parallel.
KcsA was expressed in vitro with its co-translational integration into liposoms containing asolectin lipids. The proteoliposomes were subsecuently fused with bilayer array containing POPE/POPG on the Orbit 16.
Conditions: Current traces were recorded in 20 mM MES pH 4.0 on the cis-side and 10 mM MOPS, pH 7.0 on the trans-side of the bilayer; containing 200 mM KCl symmetric solutions with membrane potential held at +150 mV.
KcsA - Bilayer Recordings
Vesicle Prep Pro data and applicatons:
The image shows a representative current trace recorded from a planar lipid bilayer in which purified KcsA channels were reconstituted (100 mM KCl, asymmetric pH; pH 4/pH 7). A ramp from -100 mV to +100 mV was used to evoke the single channel events.
Download: Application Note
Application Notes
KcsA - "Lipid bilayer recordings of KcsA channels reconstituted in proteoliposomes"
Port-a-Patch and Vesicle Prep Pro application note: 
(0.2 MB)
Posters
2016 - Parallel and automated formation of lipid bilayers on microstructured chips for ion channel and nanopore recordings
Orbit 16 poster (1.4 MB)
Kindly provided by Ionera Technologies
Publications
2019 - Modulation of the potassium channel KcsA by anionic phospholipids: Role of arginines at the non-annular lipid binding sites
Port-a Patch Publication in BBA - Biomembranes (2019)
Authors:
Poveda J.A., Giudici A.M., Renart M.L., Millet O., Morales A., González-Ros J.M., Oakes V., Furini S., Domene C
2018 - Functional Analysis of Membrane Proteins Produced by Cell-Free Translation
Port-a-Patch and 
Orbit mini article in Protein Engineering (2018)
Authors:
Dondapati S.K., Wüstenhagen D.A., Kubick S.
2016 - Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
Port-a-Patch and Vesicle Prep Pro publication in Nature Communications (2016)
Authors:
Dhakshnamoorthy B., Rohaim A., Rui H., Blachowicz L., Roux B.
2014 - Membrane assembly of the functional KcsA potassium channel in a vesicle-based eukaryotic cell-free translation system
Port-a-Patch and Vesicle Prep Pro publication in Biosensors and Bioelectronics (2014)
Authors:
Dondapati S.K., Kreir M., Quast R.B., Wüstenhagen D.A., Brüggemann A., Fertig N., Kubick S.