Chlorophyll dichroism of three‐dimensional crystals of the light‐harvesting chlorophyll a/b‐protein complex

FEBS Letters

Mäntele, W.¹  Kühlbrandt, W.²  Becker, A.¹ 

[1] Institut für Biophysik und Strahlenbiologie, Albertstr. 23, 78 Freiburg, FRG;Biophysics Section, The Blackett Laboratory, and AFRC Photosynthesis Group, Department of Pure & Applied Biology, Imperial College of Science and Technology, London SW7 2BZ, England

关键词: Chlorophyll-protein complex;    Membrane protein crystal;    Light-harvesting complex;    Microspectrophotometry;    Linear dichroism;   

DOI  :  10.1016/0014-5793(88)81438-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Thin three-dimensional crystals of the light-harvesting chlorophyll a/b-protein complex from pea chloroplast membranes were investigated by microspectrophotometry. Measurements of tilted crystals revealed pronounced linear dichroism in a direction perpendicular to the crystal plane but no observable dichroism in the crystal plane. Q_y transition moments of chlorophylls were rotationally isotropic with respect to the crystal plane and partially aligned in this plane. Q_x transition moments showed no preferential orientation and appeared to be wholly isotropic. The orientation of transition moments in the crystal was consistent with three-fold symmetry of the light-harvesting complex indicated by the crystal structure. The linear dichroism of the crystals reflected the optical properties of the complex in the photosynthetic membrane, indicating a highly symmetrical arrangement of antenna chlorophylls.

【 授权许可】

Unknown