1. X-Ray Crystallographic Analysis of 9- cis-Rhodopsin, a Model Analogue Visual Pigment.
- Author
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Nakamichi, Hitoshi and Okada, Tetsuji
- Subjects
- *
X-ray crystallography , *RHODOPSIN , *PHOTORECEPTORS , *ELECTRON distribution , *HIGH resolution electron microscopy , *RETINAL (Visual pigment) - Abstract
Recent progress in high-resolution structural study of rhodopsin has been enabled by a novel selective extraction procedure with rod photoreceptor cells. In this study, we applied the method for rapid and efficient preparation of a purified analogue pigment using bovine rod outer segment membranes with 9- cis-retinal. After complete bleaching of the membranes and subsequent regeneration with the exogenous retinal, 9- cis-rhodopsin is selectively extracted from the membranes using combination of zinc and heptylthioglucoside. The solubilized sample, even with a small amount of contaminating retinal oximes, is shown to be pure enough for three-dimensional crystallization. The X-ray diffraction from 9- cis-rhodopsin crystals was examined and the electron density map at 2.9 Å resolution in the chromophore region can be fitted well with the model of 9- cis-retinal Schiff base. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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