• KcsA

    Representative current trace recorded from a planar lipid bilayer in which purified KcsA channels were reconstituted (measured on the Port-a-Patch)

KcsA - Prokaryotic pH-gated Potassium Channel

Prokaryotic Tetrameric Potassium Channels

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

Icon Orbit   Orbit16 Ionera KcsAOrbit 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

KCSA Vesicle prep proicon vpp   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"

icon pap   Port-a-Patch and   icon vpp   Vesicle Prep Pro application note:  logo pdf   (0.2 MB)



27.01.2016 | Webinar: Instant bilayers - just add protein

Icon Orbit   Orbit 16 and   Icon Orbit Mini   Orbit Mini

Orbits V1 flat 250pxThis webinar covers the use of the lipid bilayer platforms from Nanion: the Orbit16 and the Orbit mini for characterization of membrane proteins like ion channels, bacterial porins and biological nanopores. Both bilayer systems support high quality low noise recordings, but differ in throughput capabilities and experimental features. The Orbit16, introduced in 2012 is a device for efficient formation of 16 lipid bilayers simultaneously, allowing for parallel bilayer-reconstitution of ion channels and nanopores.



2019 - Modulation of the potassium channel KcsA by anionic phospholipids: Role of arginines at the non-annular lipid binding sites

icon pap   Port-a Patch Publication in BBA - Biomembranes (2019)

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

icon pap   Port-a-Patch and   Icon Orbit Mini   Orbit mini article in Protein Engineering (2018)

Dondapati S.K., Wüstenhagen D.A., Kubick S.

2016 - Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola

icon pap  Port-a-Patch and   icon vpp   Vesicle Prep Pro publication in Nature Communications (2016)

Dhakshnamoorthy B., Rohaim A., Rui H., Blachowicz L., Roux B.

2015 - Golgi anti-apoptotic proteins are highly conserved Ion Channels That Affect Apoptosis and Cell Migration

icon pap  Port-a-Patch and   icon vpp   Vesicle Prep Pro publication in Journal of Biological Chemistry (2015)

Carrara G., Saraiva N., Parsons M., Byrne B., Prole D.L., Taylor C.W., Smith G.L.

2014 - Membrane assembly of the functional KcsA potassium channel in a vesicle-based eukaryotic cell-free translation system

icon pap  Port-a-Patch and   icon vpp   Vesicle Prep Pro publication in Biosensors and Bioelectronics (2014)

Dondapati S.K., Kreir M., Quast R.B., Wüstenhagen D.A., Brüggemann A., Fertig N., Kubick S.

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