| 释义 |
metarhodopsin Biochem.|ˌmɛtərəʊˈdɒpsɪn|
Also meta-rhodopsin.
[f. meta- + rhodopsin.]
Either of two interconvertible intermediates (the orange metarhodopsin I and the yellow metarhodopsin II) that are formed when rhodopsin is bleached by light, being produced from lumirhodopsin and undergoing spontaneous hydrolysis to retinal and opsin.
1950G. Wald et al. in Science 17 Feb. 180/1 If the solution of lumi-rhodopsin is warmed to about -20°C, a further change occurs in darkness. The absorption band shifts another 7–9 mµ toward the blue, with little further change in height or shape... We shall call this second product meta-rhodopsin. 1970G. S. Brindley Physiol. Retina (ed. 2) i. 11 Figure 1.4 shows the effect of pH on the absorption spectrum of metarhodopsin at 3·2°C. Increase of temperature favours the acid form (‘metarhodopsin II’). Ibid., It seems that when rhodopsin is bleached by light the alkaline form (‘metarhodopsin I’) is always formed first, and this passes quickly into the equilibrium mixture appropriate to the pH and temperature. 1975[see lumirhodopsin]. |