Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation.
Here we introduce a new technique that probes voltage-dependent charge displacements of excitable membrane-bound proteins using extracellularly applied radio frequency (RF, 500 kHz) electric fields. Xenopus oocytes were used as a model cell for these experiments, and were injected with cRNA encoding...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2011-02-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3046147?pdf=render |
| _version_ | 1819126017686503424 |
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| author | Sameera Dharia Richard D Rabbitt |
| author_facet | Sameera Dharia Richard D Rabbitt |
| author_sort | Sameera Dharia |
| collection | DOAJ |
| description | Here we introduce a new technique that probes voltage-dependent charge displacements of excitable membrane-bound proteins using extracellularly applied radio frequency (RF, 500 kHz) electric fields. Xenopus oocytes were used as a model cell for these experiments, and were injected with cRNA encoding Shaker B-IR (ShB-IR) K(+) ion channels to express large densities of this protein in the oocyte membranes. Two-electrode voltage clamp (TEVC) was applied to command whole-cell membrane potential and to measure channel-dependent membrane currents. Simultaneously, RF electric fields were applied to perturb the membrane potential about the TEVC level and to measure voltage-dependent RF displacement currents. ShB-IR expressing oocytes showed significantly larger changes in RF displacement currents upon membrane depolarization than control oocytes. Voltage-dependent changes in RF displacement currents further increased in ShB-IR expressing oocytes after ∼120 µM Cu(2+) addition to the external bath. Cu(2+) is known to bind to the ShB-IR ion channel and inhibit Shaker K(+) conductance, indicating that changes in the RF displacement current reported here were associated with RF vibration of the Cu(2+)-linked mobile domain of the ShB-IR protein. Results demonstrate the use of extracellular RF electrodes to interrogate voltage-dependent movement of charged mobile protein domains--capabilities that might enable detection of small changes in charge distribution associated with integral membrane protein conformation and/or drug-protein interactions. |
| first_indexed | 2024-12-22T07:49:21Z |
| format | Article |
| id | doaj.art-a9764dff28224b149cf2a54d7186cc0a |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-22T07:49:21Z |
| publishDate | 2011-02-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-a9764dff28224b149cf2a54d7186cc0a2022-12-21T18:33:32ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-02-0162e1736310.1371/journal.pone.0017363Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation.Sameera DhariaRichard D RabbittHere we introduce a new technique that probes voltage-dependent charge displacements of excitable membrane-bound proteins using extracellularly applied radio frequency (RF, 500 kHz) electric fields. Xenopus oocytes were used as a model cell for these experiments, and were injected with cRNA encoding Shaker B-IR (ShB-IR) K(+) ion channels to express large densities of this protein in the oocyte membranes. Two-electrode voltage clamp (TEVC) was applied to command whole-cell membrane potential and to measure channel-dependent membrane currents. Simultaneously, RF electric fields were applied to perturb the membrane potential about the TEVC level and to measure voltage-dependent RF displacement currents. ShB-IR expressing oocytes showed significantly larger changes in RF displacement currents upon membrane depolarization than control oocytes. Voltage-dependent changes in RF displacement currents further increased in ShB-IR expressing oocytes after ∼120 µM Cu(2+) addition to the external bath. Cu(2+) is known to bind to the ShB-IR ion channel and inhibit Shaker K(+) conductance, indicating that changes in the RF displacement current reported here were associated with RF vibration of the Cu(2+)-linked mobile domain of the ShB-IR protein. Results demonstrate the use of extracellular RF electrodes to interrogate voltage-dependent movement of charged mobile protein domains--capabilities that might enable detection of small changes in charge distribution associated with integral membrane protein conformation and/or drug-protein interactions.http://europepmc.org/articles/PMC3046147?pdf=render |
| spellingShingle | Sameera Dharia Richard D Rabbitt Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. PLoS ONE |
| title | Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. |
| title_full | Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. |
| title_fullStr | Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. |
| title_full_unstemmed | Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. |
| title_short | Monitoring voltage-dependent charge displacement of Shaker B-IR K+ ion channels using radio frequency interrogation. |
| title_sort | monitoring voltage dependent charge displacement of shaker b ir k ion channels using radio frequency interrogation |
| url | http://europepmc.org/articles/PMC3046147?pdf=render |
| work_keys_str_mv | AT sameeradharia monitoringvoltagedependentchargedisplacementofshakerbirkionchannelsusingradiofrequencyinterrogation AT richarddrabbitt monitoringvoltagedependentchargedisplacementofshakerbirkionchannelsusingradiofrequencyinterrogation |