Ion channels are massively important to all cells as they allow for the production of ion gradients as well as important ion movements into the cell. These enzymes work in very complicated and closely regulated ways which were previously unknown. New research has opened up these ion channels and dissected their processes to allow us to more closely describe their actions.
Potassium channels are key components of any cell membrane as they allow for ion gradient exchange, but are particularly important and well-studied in the neural cells of humans. By allowing only certain ions through a channel in the cellular membrane, the cell is able to manipulate ion concentration as well as pH and electronic charge (potential). This process is tightly controlled in all pumps as to not unnecessarily use energy, but is controlled particularly closely in potassium pumps. Neurons use potassium pumps as their source of bioelectricity, thus these pumps and their activation/deactivation is crucial in understanding how drugs interact with our brain. Until very recently, potassium channels were understood to encapsulate an “intrinsically disordered” protein which worked remarkably slowly by molecular standards. When the pump opens, it allows the intended ion(s) through, but quickly becomes inactive and stays this way for ten to twenty seconds, what seems like a cellular eternity. The reason for this was previously unknown.
It is now understood that this is caused by the saturation of the enzyme with twelve water molecules. Immediately after the channel opens, water molecules flow in simultaneously with the desired ion. These molecules quickly bind cavities within the pump and inactivate it, changing the enzyme by less than the radius of a carbon atom. The sheer minimality of the change had frustrated scientists in determining its cause but it is now understood that this mechanism allows for very tight control of the pump’s flow. However, this binding process happens quicker than does the opposite. Slowly after all cavities are full, the pump will begin to release the water molecules and again open up for transport, thus creating the cyclical enzymatic process.
Scientists hope that this knowledge will improve the way we think about neural interaction. By identifying some more limiting factors, as well as more information on for bioelectrical energy is created, we can better access neurons for drug application as well as general microbiological research. Studying these pumps may also have implications for other types of cells, as nearly all cells will possess potassium pumps.