Fig. 2. HPLC analysis of the retinal chromophore of AR-3 WT, DETC and ARCH-5 in the dark-adapted (DA) and the light-adapted (LA) states. (A) Representative HPLC chromatogram of the retinal oxime in dark-adapted (DA, solid line) and light-adapted (LA, dotted line) states. The retinal oxime was produced by the hydrolysis reaction between the retinal chromophore and hydroxylamine. Syn and anti refer to the configuration of the C N bond of the product retinal oxime, which does not represent the configuration of the retinal Schiff base in the original proteins. The retention time of each isomer was normalized based on that of each isomer in DA. (B) The ratio of each isomer (mean ± standard deviation, n = 3 independent experiments). Sample illumination and HPLC analysis were performed three times independently. The numbers at the top of each bar indicate the composition of each isomer.