Lipid charge regulation of non-specific biological ion channels.
Ion channels are specialized proteins that enable the movement of charges through otherwise impermeable lipidic membranes. Their action is essential in living organisms facilitating electric signaling, muscle contraction or osmotic stress response among other effects. The protein and the lipid charges configure a polarized interface that yields local ionic concentrations and electric potentials that are very different from those of the bulk electrolyte. The combined effect of gradients of ionic concentration and electric potential causes the transport of ions through channels. Here we analyze charge regulation effects in different protein-lipid conformations, stressing how important is the role of electrostatic interactions in the ion channel function that traditionally has been rationalized paying attention mainly to changes in pore size. Tuning lipid charge combined with conductance and selectivity measurements is shown to be a complementary method to evidence lipid involvement in the structure of a biological ion channel.
Dept. Physics, Lab. Molecular Biophysics, Universitat Jaume I, 12080 Castellón, Spain. aguilell@uji.es.
Vicente M
VM
Aguilella
Carmina
C
Verdiá-Báguena
Antonio
A
Alcaraz
D000408:Alamethicin / Q000737:chemistry / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D004553:Electric Conductivity; D006460:Hemolysin Proteins / Q000737:chemistry / Q000378:metabolism; D007473:Ion Channels / Q000737:chemistry* / Q000378:metabolism; D017136:Ion Transport / Q000187:drug effects; D007477:Ions / Q000737:chemistry / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D045473:Severe acute respiratory syndrome-related coronavirus / Q000378:metabolism; D055672:Static Electricity; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000378:metabolism; D000086082:Viroporin Proteins
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C501689:E protein, SARS coronavirus; D006460:Hemolysin Proteins; D007473:Ion Channels; D007477:Ions; D008055:Lipids; D014759:Viral Envelope Proteins; D000086082:Viroporin Proteins; D000408:Alamethicin