Review Article - (2020) Volume 8, Issue 4
Ion channels are pore–forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume. Ion channels are present in the membranes of all cells. Ion channels are one of the two classes of ionophoric proteins, the other being ion transporters. The study of ion channels often involves biophysics, electrophysiology, and pharmacology, while using techniques including voltage clamp, patch clamp, immunohistochemistry, X–ray crystallography, fluoroscopy, and RT–PCR. Their classification as molecules is referred to as channelomics. The fundamental properties of currents mediated by ion channels were analyzed by the British biophysicists Alan Hodgkin and Andrew Huxley as part of their Nobel Prize–winning research on the action potential, published in 1952. They built on the work of other physiologists, such as Cole and Baker's research into voltage–gated membrane pores from 1941. The existence of on channels was confirmed in the 1970s by Bernard Katz and Ricardo Miledi using noise analysis. It was then shown more directly with an electrical recording technique known as the "patch clamp", which led to a Nobel Prize to Erwin Neher and Bert Sakmann, the technique's inventors. Hundreds if not thousands of researchers continue to pursue a more detailed understanding of how these proteins work. In recent years the development of automated patch clamp devices helped to increase significantly the throughput in ion channel screening.
The Nobel Prize in Chemistry for 2003 was awarded to Roderick MacKinnon for his studies on the physico–chemical properties of ion channel structure and function, including x–ray crystallographic structure studies.
