15-cis-beta-carotene found in the reaction center of spinach photosystem II.

Solvent extraction at approximately 4 degrees C in complete darkness, and subsequent analysis by high-pressure liquid chromatography (at approximately 4 degrees C) using an apparatus equipped with a two-dimensional diode-array detector, spectroscopically identified 15-cis-beta-carotene in the reaction center (RC) of spinach photosystem II (PS II). The result revises a previous conclusion that beta-carotene bound to the PS II RC takes the all-trans configuration [Fujiwara, H., Hayashi, H., Tasumi, M., Kanaji, M., Koyama, Y. and Satoh, K. (1987) Chem. Lett. 2005-2008], and generalizes the concept established for purple photosynthetic bacteria that 15-cis-carotenoid is naturally selected by the photosynthetic reaction centers.