ジャーナル: Nat Chem Biol / 年: 2024 タイトル: De novo design of proteins housing excitonically coupled chlorophyll special pairs. 著者: Nathan M Ennist / Shunzhi Wang / Madison A Kennedy / Mariano Curti / George A Sutherland / Cvetelin Vasilev / Rachel L Redler / Valentin Maffeis / Saeed Shareef / Anthony V Sica / Ash Sueh ...著者: Nathan M Ennist / Shunzhi Wang / Madison A Kennedy / Mariano Curti / George A Sutherland / Cvetelin Vasilev / Rachel L Redler / Valentin Maffeis / Saeed Shareef / Anthony V Sica / Ash Sueh Hua / Arundhati P Deshmukh / Adam P Moyer / Derrick R Hicks / Avi Z Swartz / Ralph A Cacho / Nathan Novy / Asim K Bera / Alex Kang / Banumathi Sankaran / Matthew P Johnson / Amala Phadkule / Mike Reppert / Damian Ekiert / Gira Bhabha / Lance Stewart / Justin R Caram / Barry L Stoddard / Elisabet Romero / C Neil Hunter / David Baker / 要旨: 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 ...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 independently of the complexities of native photosynthetic proteins, and as a first step toward creating synthetic photosystems for new energy conversion technologies, we designed C-symmetric proteins that hold two chlorophyll molecules in closely juxtaposed arrangements. X-ray crystallography confirmed that one designed protein binds two chlorophylls in the same orientation as native special pairs, whereas a second designed protein positions them in a previously unseen geometry. Spectroscopy revealed that the chlorophylls are excitonically coupled, and fluorescence lifetime imaging demonstrated energy transfer. The cryo-electron microscopy structure of a designed 24-chlorophyll octahedral nanocage with a special pair on each edge closely matched the design model. The results suggest that the de novo design of artificial photosynthetic systems is within reach of current computational methods.