| First Author | Yue WW | Year | 2017 |
| Journal | Elife | Volume | 6 |
| PubMed ID | 28186874 | Mgi Jnum | J:258156 |
| Mgi Id | MGI:6140697 | Doi | 10.7554/eLife.18492 |
| Citation | Yue WW, et al. (2017) Spontaneous activation of visual pigments in relation to openness/closedness of chromophore-binding pocket. Elife 6:e18492 |
| abstractText | Visual pigments can be spontaneously activated by internal thermal energy, generating noise that interferes with real-light detection. Recently, we developed a physicochemical theory that successfully predicts the rate of spontaneous activity of representative rod and cone pigments from their peak-absorption wavelength (lambdamax), with pigments having longer lambdamax being noisier. Interestingly, cone pigments may generally be ~25 fold noisier than rod pigments of the same lambdamax, possibly ascribed to an ''open'' chromophore-binding pocket in cone pigments defined by the capability of chromophore-exchange in darkness. Here, we show in mice that the lambdamax-dependence of pigment noise could be extended even to a mutant pigment, E122Q-rhodopsin. Moreover, although E122Q-rhodopsin shows some cone-pigment-like characteristics, its noise remained quantitatively predictable by the ''non-open'' nature of its chromophore-binding pocket as in wild-type rhodopsin. The openness/closedness of the chromophore-binding pocket is potentially a useful indicator of whether a pigment is intended for detecting dim or bright light. |
