| Autor: |
Hakobyan, M., Poladyan, A., Bagramyan, K. |
| Zdroj: |
Biophysics; Jun2006, Vol. 51 Issue 3, p418-422, 5p |
| Abstrakt: |
A correlation between the rate of ATP synthesis by F0F1 ATP synthase and formate oxidation by formate hydrogen lyase (FHL) has been found in inside-out membrane vesicles of the Escherichia coli mutant JW 136 (Δ hya/Δ hyb) with double deletions of hydrogenases 1 and 2, grown anaerobically on glucose in the absence of external electron acceptors at pH 6.5. ATP synthesis was suppressed by the H+-ATPase inhibitors N,N′-dicyclohexylcarbodiimide, sodium azide, and the uncoupler carbonyl cyanide m-chlorophenylhydrazone. Copper ions inhibited formate-dependent hydrogenase and ATP-synthase activities but did not affect the ATPase activity of the vesicles. The maximal rate of ATP synthesis (0.83 μmol/min per mg protein) was determined at simultaneous application of sodium formate, ADP, and inorganic phosphate, and was stimulated by K+ ions. The results confirm the assumption of a dual role of hydrogenase 3, the formate hydrogen lyase subunit that can couple the reduction of protons to H2 and their translocation through membrane with chemiosmotic synthesis of ATP. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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