Isolation of CP43 and CP47 Photosystem II Proximal Antenna Complexes From Plants

A single-column method to purify the CP43 and CP47 pigment-protein complexes of photosystem (PS)II from higher plants is presented. To validate the isolation procedure, three different species were used (Spinacea oleracea, Beta vulgaris , and Glycine max ), and the procedure worked similarly with all three. Oxygen-evolving core complex obtained from highly enriched PSII membrane fragments were used as the starting material. The core complex is treated with the chaotropic agent LiClO₄ and the nonionic detergent n -dodecyl β-D -maltoside. After dialysis against buffer with no detergent or chaotropic agent, the solubilized material is separated by weak anion-exchange chromatography using a TSK-GEL Toyopearl DEAE 650s column. CP43 complex does not bind to the column and elutes with the first pigmented fractions. When the eluate becomes colorless, the column is subjected to a 0–175 mM LiClO₄ linear gradient. The main pigment elution band corresponds to CP47 complex. The last pigmented elution band contains both reaction center-CP47 and reaction center complexes.