抄録
Photosynthetic proteins for antenna, photosystems and electron transport mostly occur as protein complex or supercomplex in the thylakoid membrane to support coordinated flow of energy and reducing equivalents. The organization of these complexes can be probed by various techniques and the blue-native polyacrylamide gel electrophoresis (BN-PAGE) is one of the powerful tools of high resolution. We will review the general principle and behavior of the photosystem II (PSII), photosystem I (PSI), and light-harvesting antenna complexes in BN-PAGE. The PSII core complex of cyanobacteria and plants can be separated as a monomer and a dimer and their ratio often depends on the condition of solubilization: stronger treatment with detergent tends to yield higher dimer-to-monomer ratio. By contrast, organization of PSI is diversified in evolution. Generally, a trimer and a monomer are popular in cyanobacteria, while a monomeric PSI-LHCI supercomplex is predominant in green plants and chlorophyll c-containing algae. However, we recently demonstrated "tetrameric" organization of PSI in heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 and a glaucocystophyte Cyanophora paradoxa.
