Retinal-Carotenoid Interactions in a Sodium-Ion-Pumping Rhodopsin: Implications on Oligomerization and Thermal Stability.

ABSTRACT: Microbial rhodopsin (also called retinal protein)-carotenoid conjugates represent a unique class of light-harvesting (LH) complexes, but their specific interactions and LH properties are not completely elucidated as only few rhodopsins are known to bind carotenoids. Here, we report a natural sodium-ion (Na⁺)-pumping Nonlabens (Donghaeana) dokdonensis rhodopsin (DDR2) binding with a carotenoid salinixanthin (Sal) to form a thermally stable rhodopsin-carotenoid complex. Different spectroscopic studies were employed to monitor the retinal-carotenoid interaction as well as the thermal stability of the protein, while size-exclusion chromatography (SEC) and homology modeling are performed to understand the protein oligomerization process. In analogy with that of another Na

SUBMITTER: Ghosh M 

PROVIDER: S-EPMC10026069 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature