Transmembrane orientation of α‐helices and the organization of chlorophylls in photosynthetic pigment‐protein complexes

FEBS Letters

Nabedryk, Eliane¹  Breton, Jacques¹ 

[1] Service de Biophysique, Département de Biologie, CEN Saclay, 91191 Gif-sur- Yvette, Cêdex, France

关键词: Chlorophyll-protein complex;    α-Helix;    β-Sheet;    UV circular dichroism;    Infrared dichroism;    Transmembrane orientation;    CD;    circular dichroism;    IR;    infrared;    Chl;    chlorophyll;    BChl;    bacteriochlorophyll;    LHC;    lightharvesting complex;   

DOI  :  10.1016/0014-5793(84)81196-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

UV CD and IR spectra of the water-soluble bacteriochlorophyll-protein antenna isolated from Prosthecochloris aestuarii indicate that about 50% of the protein is in a β-sheet conformation while for the dominant antenna complexes isolated from bacteria (B800-850) and from green plants (LHC), the α-helix (45%) is more abundant than the β-sheet (~ 10%) conformation. Furthermore, IR dichroism studies show that the α-helical segments of a large variety of intrinsic membrane Chl-protein complexes (antenna and reaction centers) are tilted on the average at 30–35° away from the membrane normal. The observation that in these complexes the Chl planes are also tilted at about the same angle suggests that the transmembrane orientation of the α-helices determines the positioning of the Chl molecules in photosynthetic membranes.

【 授权许可】

Unknown