Conformational Differences among Metarhodopsin I, Metarhodopsin II, and Opsin Probed by Wide-Angle X-ray Scattering
نویسندگان
چکیده
منابع مشابه
Structural comparison of metarhodopsin II, metarhodopsin III, and opsin based on kinetic analysis of Fourier transform infrared difference spectra.
Fourier transform infrared difference spectra were measured at 30-s intervals after a complete bleach of rhodopsin (rho) samples at 20 degrees C and three different pH values. At each pH, all of the spectra could be fit globally to two exponential decay processes. Using a branched unimolecular kinetic model in which metarhodopsin II (meta II) is hydrolyzed to opsin and retinal both directly and...
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Rhodopsin is a 7-helix, integral membrane protein found in the rod outer segments, which serves as the light receptor in vision. Light absorption by the retinylidene chromophore of rhodopsin triggers an 11-cis-->all-trans isomerization, followed by a series of protein conformational changes, which culminate in the binding and activation of the G-protein transducin by the metarhodopsin II (Meta ...
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The equilibria between metarhodopsins I and II (MI and MII) and the binding of MII to retinal G protein (G) were investigated, using the dual wavelength absorbance response of rod disk membrane (RDM) suspensions to a series of small bleaches, together with a nonlinear least-squares fitting procedure that decouples the two reactions. This method has been subjected to a variety of theoretical and...
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The effects of ionic strength on formation and decay of metarhodopsin II (MII), the active photointermediate of bovine rhodopsin, were studied in the native membrane environment by means of ultraviolet/ visible and Fourier-transform infrared (FTIR) spectroscopy. By increasing the concentration of KCl in the range from hypotonic to 4 M, the apparent pKa of the metarhodopsin I(MI)/MII equilibrium...
متن کاملConformational Dynamics of Rhodopsins Visualized by Time-resolved Wide Angle X-ray Scattering
Rhodopsins are a family of light-sensitive proteins found in the cellular membranes of a wide range of living organisms. These membrane proteins share a common molecular architecture and are able to use light energy to perform a variety of different biological functions. Mapping the conformational changes required for these proteins to function is important for understanding how light energy is...
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ژورنال
عنوان ژورنال: The Journal of Physical Chemistry B
سال: 2019
ISSN: 1520-6106,1520-5207
DOI: 10.1021/acs.jpcb.9b08311