Inhibition of N-ethylmaleimide of the MgATP-driven proton pump of the chromaffin granules
| Autor: | Torgeir Flatmark, Sissel Vik Berge, Eystein S. Husebye, Martin Grønberg |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Proton channel
ATPase Biophysics Ethylmaleimide Biochemistry chemistry.chemical_compound Adenosine Triphosphate Structural Biology ATP hydrolysis Organelle Adrenal Glands Genetics medicine Animals heterocyclic compounds Chromaffin Granules Molecular Biology Adrenal medulla Membrane potential N N-Dicyclohexylcarbodiimide Adenosine Triphosphatases biology N-Ethylmaleimide Cell Biology Hydrogen-Ion Concentration Proton pump Kinetics Proton-Translocating ATPases medicine.anatomical_structure chemistry Chromaffin System N-ethylmaleimide biology.protein H+-ATPase Cattle |
| Zdroj: | FEBS letters. 149(1) |
| ISSN: | 0014-5793 |
| Popis: | The thiol reagent N-ethylmaleimide (NEM) completely inhibits the proton pump activity of the H+-ATPase in chromaffin granule 'ghosts' at concentrations which only partly (approximately 20%) inhibit the Mg2+-dependent ATP hydrolysis. Half-maximal inhibition was obtained at approximately 13 microM NEM as compared to 18 microM for the classical proton channel inhibitor N,N'-dicyclohexylcarbodiimide (DCCD), and the apparent stoichiometry of the inhibitors at complete inhibition was NEM : DCCD congruent to 1 : 2. HIgh concentrations of NEM (greater than 100 microM) induce a dissipation of the transmembrane potential generated by MgATP. These findings establish NEM as a valuable proton channel inhibitor in chromaffin granules and explain the rather complex effect of NEM previously reported for catecholamine accumulation in this organelle. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text