Fig. 1

Molecular characteristics of Opn5L1. a, b Absorption spectra (a) and HPLC patterns of retinal chromophore (b) of Opn5L1NC purified after incubation with 11-cis- (black) or all-trans-retinal (red). The spectra were recorded at 10 °C. c G protein activation ability of Opn5L1N before (black) and after (red) irradiation with >500 nm light for 2 min. d, e Absorption spectra (d), and HPLC patterns of retinal chromophore (e) of Opn5L1NC before (black) and after (red) irradiation with >500 nm light for 2 min. The spectra were recorded at 10 °C. f Absorption spectra before (Dark) and 0.0015, 0.017, 0.05, 0.16, and 2.1 s (curves 1−5, respectively) after flash irradiation with >500 nm light at 37 °C. g The absorbance at 495 nm (black circles) and 270 nm (red triangles) plotted against the time after flash irradiation. The time profiles were fitted by single exponential functions y = y₀ − b × exp(−t/τ) with the same time constant (solid curves, y = 0.0059 − 0.054 × exp(t/0.089) for 495 nm, and y = 0.167 – 0.017 × exp(t/0.089) for 270 nm, τ = 0.089 s). h Absorption spectra before (Dark) and 0, 11, 32, 92, 447, and 557 min (curves 1−6, respectively) after irradiation with >500 nm light for 2 min at 37 °C. (inset) The absorbance at 510 nm plotted against the time after irradiation (black circles). The data were fitted by single exponential function y = y₀ − b × exp(−t/τ) (solid curve, y = 0.029 – 0.026 × exp(t/10500), τ = 1.1×10⁴ s). i HPLC patterns of retinaloximes extracted before (black) and 2 min (red) or 11 h (cyan) after light irradiation. j Recovery of G protein activation efficiency of Opn5L1N after light irradiation. G protein activation efficiencies estimated with (red squares) and without (black circles) additional light irradiation were plotted against incubation time. Data points represent mean values ± s.d. (n = 3). Kinetics of the increase of G protein activation efficiency were fitted by a single exponential function (broken line) with a time constant of 7.5×10³ s