Mechanism of blockage of amphotericin B channels in a lipid bilayer
| Autor: | Marina P. Borisova, L.N. Ermishkin, A.Ya. Silberstein |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
Membrane potential
Tetraethylammonium Stereochemistry Biophysics Electric Conductivity Conductance Ionic bonding Membranes Artificial Cell Biology Tetraethylammonium Compounds Biochemistry Models Biological Potassium channel Ion Channels Ion Membrane Potentials chemistry.chemical_compound Membrane Cholesterol chemistry Amphotericin B Lipid bilayer Phospholipids |
| Zdroj: | Biochimica et biophysica acta. 553(3) |
| ISSN: | 0006-3002 |
| Popis: | A number of organic compounds (non-electrolytes, tetraalkylammonia, etc.) with a molecular size of 6–8 A decrease the conductance of ionic channels formed in the lipid bilayer by a polyene antibiotic amphotericin B. It is suggested that these compounds, upon entering the channel, block the passage of inorganic ions. The extent of conductance blockage by organic ions depends on the membrane potential and electrolyte concentration. In the presence of ionic blockers, for instance tetraethylammonium, amphotericin B-containing membranes assume some properties characteristic of excitable membranes, i.e. the current-voltage characteristic acquires the negative resistance region, and in response to a potential step activation followed by inactivation of conductance is observed. It is shown that the potential dependence of the blockage is due to interaction inside the channel of the blocker ion with penetrating ions, by a mechanism similar to that described by Armstrong ((1979) Q. Rev. Biophys. 7, 179–210) for blockage of squid axon potassium channels by ammonium derivatives. |
| Databáze: | OpenAIRE |
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