Potassium Channel Assays
Potassium channels are the most common form of ion channel and can be found in almost every living thing. They bridge cell membranes and generate potassium-selective pores. Potassium channels transport potassium ions down their electrochemical gradient quickly and selectively. In many cells, these channels function to set or reset the resting potential. The delayed counterflow of potassium ions modifies the action potential in excitable cells like neurons.
Creative Biolabs provides a measure of channel activity under physiologically relevant conditions. Early in the lead evaluation and optimization process, our potassium channel tests are useful for screening drugs for target activity.
| Classification | Function | Subclassification |
| Voltage Gated Potassium Channel Assays |
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| Calcium and Sodium Activated Potassium Channel Assays |
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| Inwardly Rectifying Potassium Channel Assays |
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| Two P Domain Potassium Channel Assays |
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Pharmacology
Potassium ions cannot pass via potassium channels when potassium channel blockers are present. They either bind outside the filter to block ion conduction or compete with potassium binding inside the selectivity filter. Quaternary ammonium ions, which bind at the extracellular face or core cavity of the channel, are an illustration of one of these competitors. Quaternary ammonium ions are also known as open channel blockers since binding traditionally necessitates the opening of the cytoplasmic gate first. Barium ions have a high affinity binding site within the selectivity filter, which allows them to inhibit potassium channel currents as well. Barium toxicity is hypothesized to be caused by a strong binding that prevents potassium channel activation in excitable cells. It has been researched if potassium channel blockers, such as 4-aminopyridine and 3,4-diaminopyridine, can be used to treat diseases like multiple sclerosis. Off-target pharmacological effects can result in drug-induced Long QT syndrome, a condition that could be fatal. The impact on the heart's hERG potassium channel is mostly to blame for this. As a result, the safety of novel medications for the heart is preclinically studied. It has been researched if potassium channel blockers, such as 4-aminopyridine and 3,4-diaminopyridine, can be used to treat diseases like multiple sclerosis.
Fig.1. Potassium channel. (Doyle, 1998)
Reference
- Doyle, D. A.; et al. The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science. 1998, 280(5360): 69-77.
