Studies on the polypeptide composition of the cyanobacterial oxygen-evolving complex

摘要: Abstract Various approaches have been used to investigate the polypeptides required for oxygen evolution in cyanobacteria, particular thermophile Phormidium laminosum . Antibodies against extrinsic 33 kDa protein from spinach Photosystem II cross-reacted clearly immunoblotting experiments with a corresponding polypeptide isolated thylakoids and particles P. whole-cell homogenates of three species cyanobacteria ( laminosum, Synechococcus leopoliensis Anabaena variabilis ). In contrast, no cyanobacterial proteins reacted antibodies 23 16 II. The lack cross-reactivity absence these highly active strongly suggest that do not contain two chloroplast proteins. Treatment 0.8 M alkaline Tris, 1 NaCl, CaCl 2 or MgCl inhibited O evolution, quantitatively removed 9 particles. None treatments comparable amounts polypeptide, only Tris treatment manganese. release upon NaCl correlated well deactivation at donor side A direct connection between was established by finding trypsin digested this parallel.