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Reversible spectral change of squid retinochrome by salts


THE cephalopod retina contains two kinds of photosensitive pigments, rhodopsin and retinochrome. Retinochrome was first found in the inner segment of squid visual cells1. More recently it was reported that the outer segment might also contain retinochrome together with rhodopsin2. The chromophore of retinochrome, all-trans retinal, is predominantly converted into the 11-cis form by illumination. It has been suggested that retinochrome supplies 11-cis retinal for the regeneration of cephalopod rhodopsin in the dark, by acting as an isomerase1. The validity of the mechanism, however has not yet been established in vitro or in situ.

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AZUMA, K., AZUMA, M., SAKAGUCHI, K. et al. Reversible spectral change of squid retinochrome by salts. Nature 253, 206–207 (1975).

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