| Autor: |
Manor D; Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461., Hasselbacher CA, Spudich JL |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemistry [Biochemistry] 1988 Aug 09; Vol. 27 (16), pp. 5843-8. |
| DOI: |
10.1021/bi00416a004 |
| Abstrakt: |
Effects of membrane potential on photochemical reactions of three retinal-containing chromoproteins in Halobacterium halobium, sensory rhodopsin I (sR-I), bacteriorhodopsin, and halorhodopsin, are described. Each of the three exhibits a decreased rate of thermal decay of its principal intermediate when photoactivated in an artificially energized compared to a deenergized membrane. The similar response of the three pigments suggests a voltage-dependent conformational change common to their respective photocycles. Spectral and kinetic properties of the sR-I photochemical reaction cycle were measured in phototactic H. halobium cells, and differences from in vitro photocycle kinetics were attributable to the electrical membrane potential present in vivo. In vivo sR-I photocycling rates were reproduced in envelope vesicle preparations in the presence of a valinomycin-induced potassium diffusion potential. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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