Sedimentation Analysis of the State of Aggregation of the Oxygen-Evolving Photosystem II Reaction Center Core Complex and the Extrinsic Proteins

概要

論文の詳細を見る
Photosystem (PS) II core complexes that had been solubilized by the use of octyl-β-D-glucopyranoside were centrifuged in a sucrose density gradient in the presence of the detergent for determination of M_r of the oxygen-evolving PS II unit. From its sedimentation velocity relative to those of M_r standards, the oxygen-evolving PS II core complexes appeared to have an M_r of 590, 000, which is twice the sum of the M_r of the individual subunit proteins and prosthetic small molecules of PS II. The sedimentation velocity of the PS II core complex from CaCl_2-treated PS II membranes was markedly lower than that of the oxygen-evolving PS II core complex and corresponded to an M_r of 370,000. Sedimentation velocities of the isolated extrinsic proteins of 33 kDa, 24 kDa, and 18 kDa corresponded to their respective M_r's. The absence of the dimeric 33-kDa protein in the OGP-containing solution ruled out the cross-linking of PS II core complexes through self-association between 33-kDa extrinsic proteins. Dissociation of the dimeric PS II reaction center complexes may arise from the structure of the complex destabilized upon the dissociation of the extrinsic 33-kDa protein from the PS II complex.
社団法人日本農芸化学会の論文
1994-12-23