Submicromolar Ag +increases passive Na +permeability and inhibits the respiration-supported formation of Na +gradient in Bacillus FTUvesicles
In: FEBS Letters, Jg. 269 (1990), Heft 1, S. 69-72
serialPeriodical
Zugriff:
The effect of Ag +on Na +pumping by Na +-motive NADH-quinone reductase and terminal oxidase has been studied in Bacillus FTUinside-out vesicles. Very low concentrations of Ag +(C 12= 1 × 10 −8M or 2 × 10 −12g ion · mg protein −1) are shown to inhibit the uphill Na +uptake coupled to the oxidation of NADH by fumarate or of ascorbate + TMPD by oxygen but exert no effect on the H +uptake by the H +-motive respiratory chain. Low Ag +also induces a specific increase in the Na +permeability of the vesicles. HQNO, added before and not after Ag +, prevents the Ag +-induced permeability increase, with effective HQNO concentrations being similar to those inhibiting the uphill Na +-uptake coupled to the NADH-fumarate oxidoreduction. Reduction of terminal oxidase by ascorbate + TMPD in the presence of cyanide sensitizes the Na +permeability to Ag +. It is suggested that low [Ag +], known as a specific inhibitor of electron transport by the Na +-motive NADH-quinone reductase, uncouples the electron and Na +transports so that the Ag +-modified NADH-quinone reductase operates as an Na +channel rather than an Na +pump. This effect is discussed in connection with the antibacterial action of Ag +.
Titel: |
Submicromolar Ag +increases passive Na +permeability and inhibits the respiration-supported formation of Na +gradient in Bacillus FTUvesicles
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Autor/in / Beteiligte Person: | Semeykina, Anna L. ; Skulachev, Vladimr P. |
Zeitschrift: | FEBS Letters, Jg. 269 (1990), Heft 1, S. 69-72 |
Veröffentlichung: | 1990 |
Medientyp: | serialPeriodical |
ISSN: | 0014-5793 (print) |
DOI: | 10.1016/0014-5793(90)81120-D |
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