| Autor: |
Kolesnikov AV; Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia., Shukolyukov SA, Cornwall MC, Govardovskii VI |
| Jazyk: |
angličtina |
| Zdroj: |
Vision research [Vision Res] 2006 May; Vol. 46 (10), pp. 1665-75. Date of Electronic Publication: 2005 Sep 08. |
| DOI: |
10.1016/j.visres.2005.07.032 |
| Abstrakt: |
We measured the kinetics of recombination of 11-cis-retinal with opsin in intact frog rod outer segment (ROS). The rhodopsin in ROS was bleached and allowed to decay to "indicator yellow," a photoproduct where all-trans-retinal is partly free, and partly bound to non-specific amino groups of disk membranes. By briefly illuminating the "indicator yellow" by an intense 465 or 380-nm flash, we then photoconverted all-trans-retinal to (mostly) the 11-cis- form thus introducing into ROS a certain amount of cis-chromophore. The recombination of cis-retinal with opsin and the formation of rhodopsin were followed by fast single-cell microspectrophotometry. Regeneration proceeded with a time constant of approximately 3.5 min; up to 27% of bleached visual pigment was restored. The regenerated pigment consisted of 91% rhodopsin (11-cis-chromophore) and 9% of presumably isorhodopsin (9-cis-chromophore). The recombination of 11-cis-retinal with opsin inside the ROS proceeds substantially faster than rhodopsin regeneration in the intact eye and, hence, is not the rate-limiting step in the visual cycle. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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