title: Purification and characterization of photosystem I and photosystem II core complexes from wild-type and phycocyanin-deficient strains of the cyanobacterium Synechocystis PCC 6803.
abstract: Highly photoactive Photosystem I (PS I) and Photosystem II (PS II) core complexes have been isolated from the cyanobacterium Synechocystis Pasteur Culture Collection (PCC) 6803 and a phycocyanin-deficient mutant, enriched in PS II. Cell breakage using glass beads was followed by sucrose density gradient centrifugation and two high-performance liquid chromatography steps involving anion-exchange and hydroxyapatite. The PS I core complex has an apparent molecular mass of 300 +/- 20 kDa (including a detergent shell of about 50 kDa) and contains subunits of approximately 60, approximately 60, 18.5, 18.5, 16, 15, 10.5, 9.5, and 6.5 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblots; its antenna size is 75 +/- 5 chlorophyll/P-700. The PS II core complex has an apparent molecular mass of 310 +/- 20 kDa (including the detergent shell); subunits of 43, 37, 33, 29, and 10-11 kDa were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The antenna size of the average PS II complex is 45 +/- 5 chlorophyll/primary quinone electron acceptor (QA). This preparation procedure also yields, as a byproduct, a highly purified cytochrome b6f complex. This complex contains four subunits of 38, 24, 19, and 15 kDa and b- and c-type cytochromes in a ratio of 2:1. Its apparent molecular mass of 180 +/- 20 kDa (including the detergent shell) is consistent with a monomeric complex.
authors.affiliation: E. I. du Pont de Nemours & Co., Central Research and Development Department, Wilmington, Delaware 19880-0173.
authors.forename: M
authors.initials: M
authors.lastname: Rögner
authors.forename: P J
authors.initials: PJ
authors.lastname: Nixon
authors.forename: B A
authors.initials: BA
authors.lastname: Diner
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D007425:Intracellular Membranes / Q000378:metabolism; D008970:Molecular Weight; D009154:Mutation; D015388:Organelles / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins; D010798:Phycocyanin / Q000235:genetics; D013053:Spectrophotometry
chemical_list: D001426:Bacterial Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D010798:Phycocyanin