Abstract
Like other proteins, ion channels are charged. The amino acid sequence contains acidic and basic amino acids that are positively or negatively charged at physiologic pH. Other charges are added by posttranslational events such as the addition of sialic acid during complex carbohydrate trimming and phosphorylation. At least some of the charges appear to be essential for ion channel function as part of ligand and permeant ion binding sites and as the voltage sensor of voltage-gated channels (e.g. 35). Surface charges also contribute to channel function in more subtle ways. Any charge on or near the surface of a channel will polarize the surrounding environment, thus establishing an electrostatic potential, i.e. the surface potential, between the channel and aqueous solution (e.g. 54). The surface potential will alter the surrounding ionic atmosphere and change the con centrations of all charged solutes (permeant ions, toxins, or ligands). Op positely charged solutes (counterions) will be attracted to the charge and
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
