A COMPARISON OF LIGHT-TRIGGERED SPECTRAL CHANGES IN RHODOPSIN AND ISORHODOPSIN |
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| Authors: | P. B. LAM D. C. PRATT |
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| Affiliation: | Botany Department, University of Minnesota, Minneapolis, Minn. 55455, U.S.A. |
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| Abstract: | Abstract— This report describes spectral changes associated with the transformation of metarhodopsin I to metarhodopsin II following light excitation of isorhodopsin and rhodopsin. Irradiated isorhodopsin gives rise to an equilibrium mixture of metarhodopsin I and metarhodopsin II which at 2°C and pH 6.8 favors the former. Isorhodopsin and rhodopsin are converted to metarhodopsin II via metarhodopsin I at very similar rates and activation parameters for the conversions are essentially identical. It is concluded that the initial cis to trans isomerization erases all differences in the two pigments. |
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