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This study highlights similarities and differences in the formation of visual molecules between humans and insects. It demonstrates the enzyme activity of NinaB in insects compared to CCD enzymes in vertebrates for the production of 11-cis-retinal, crucial for vision. This research sheds light on the evolution and diversification of vision systems among different species.
Nature Chemical Biology (2024). DOI: 10.1038/s41589-024-01554-z”> Enzymatic activity of TnNinaB toward carotenoid and xanthophyll substrates. a, NinaB isomerooxygenases found in insects (represented by the moth silhouette) cleave β-carotene (1) to generate all-trans-RAL (2) and the visual chromophore 11-cis-RAL (3). In vertebrates (represented by the human silhouette), 11-cis-RAL biosynthesis requires two separate CCD enzymes (BCO1 and RPE65). b, HPLC chromatograms demonstrating that TnNinaB displays isomerooxygenase activity toward β-carotene. c, Schematic of NinaB activity towards zeaxanthin (4) generating (3R)-3-hydroxy-all-trans-RAL (5) and (3R)-3-hydroxy-11-cis-RAL (6), the latter serving as the visual chromophore in insects. d, HPLC chromatograms demonstrating that TnNinaB displays isomerooxygenase activity toward zeaxanthin. e, Schematic of NinaB activity toward the asymmetric xanthophyll, lutein (7), generating (3R,6R)-3-hydroxy-all-trans-α-RAL (8) and (3R)-3-hydroxy-11-cis-RAL (6). f, HPLC chromatograms demonstrating that TnNinaB displays isomerooxygenase activity toward lutein. BSA was used as a negative control for the assays. RAL products were converted into oxime derivatives before HPLC analysis, which is indicated by asterisks next to compound numbers in b, d and f. Chromatograms were recorded at a wavelength of 360 nm. Insets in b, d and f show absorbance spectra for each of the labeled peaks confirming their identities. Numbers above spectral maxima are in nanometers. The data are representative of three replicates. Credit: Nature Chemical Biology (2024). DOI: 10.1038/s41589-024-01554-z
Researchers at the University of California, Irvine have discovered profound similarities and surprising differences between humans and insects in the production of the critical light-absorbing molecule of the retina, 11-cis-retinal, also