Channel membrane protein

Channel membrane protein refers to a protein complex that is involved in the specific transport of ions or uncharged molecules along their chemical or electrochemical potential gradient. Most channels exist in two conformational states, open and closed. The opening can be achieved by:

• a propagating electric field (potentially controlled channels)
• by binding a specific ligand (chemically controlled channels)
• by mechanical stress or strain (mechanically controlled channels).

When open, the specific site in the channel can temporarily bind dissolved substances from both sides of the membrane.