Human Blue Cone Opsin Regeneration Involves Secondary Retinal Binding with Analog Specificity.

ABSTRACT: Human color vision is mediated by the red, green, and blue cone visual pigments. Cone opsins are G-protein-coupled receptors consisting of an opsin apoprotein covalently linked to the 11-cis-retinal chromophore. All visual pigments share a common evolutionary origin, and red and green cone opsins exhibit a higher homology, whereas blue cone opsin shows more resemblance to the dim light receptor rhodopsin. Here we show that chromophore regeneration in photoactivated blue cone opsin exhibits intermediate transient conformations and a secondary retinoid binding event with slower binding kinetics. We also detected a fine-tuning of the conformational change in the photoactivated blue cone opsin binding site that alters the retinal isomer binding specificity. Furthermore, the molecular models of

SUBMITTER: Srinivasan S 

PROVIDER: S-EPMC5883618 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature