De novo design of energy transfer proteins housing excitonically coupled chlorophyll special pairs.

ABSTRACT: Natural photosystems couple light harvesting to charge separation using a "special pair" of chlorophyll molecules that accepts excitation energy from the antenna and initiates an electron-transfer cascade. To investigate the photophysics of special pairs independent of complexities of native photosynthetic proteins, and as a first step towards synthetic photosystems for new energy conversion technologies, we designed C ₂ -symmetric proteins that precisely position chlorophyll dimers. X-ray crystallography shows that one designed protein binds two chlorophylls in a binding orientation matching native special pairs, while a second positions them in a previously unseen geometry. Spectroscopy reveals excitonic coupling, and fluorescence lifetime imaging demonstrates energy transfer.

SUBMITTER: Ennist N 

PROVIDER: S-EPMC10153362 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature