title: Isolation and characterization of photosystem II of Porphyra yezoensis Ueda.
abstract: The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were solubilized with SDS, the photosystem II (PSII) particles were isolated and purified. The activity of PSII particles was determined with DCIP (2,6-dichloroindophenol) photoreduction reaction. The composition of purified PSII particles was detected by SDS-PAGE. As a result, seven proteins including 55 kD protein, 47 kD protein, 43 kD protein, 33 kD protein, 31 kD protein, 29 kD protein, and 18 kD protein were found. Compared with PSII particles of higher plants and other algae, they were identified as D1/D2 complex, CP47, CP43, 33 kD protein, D1, D2 and cyt c-550 respectively. Besides, other three new proteins of 20 kD, 16 kD and 14 kD respectively were found. Among these extrinsic proteins, the 16 kD and 14 kD proteins had not been reported previously, and the 20 kD protein was found for the first time in multicellular red algae.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, the Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Zheng-Quan
authors.initials: ZQ
authors.lastname: Gao
authors.forename: Guang-Ce
authors.initials: GC
authors.lastname: Wang
authors.forename: Cheng-Kui
authors.initials: CK
authors.lastname: Tseng
mesh_terms: D015086:2,6-Dichloroindophenol / Q000494:pharmacology; D002499:Centrifugation, Density Gradient; D004591:Electrophoresis, Polyacrylamide Gel; D056890:Eukaryota / Q000502:physiology; D008027:Light; D045332:Photosystem II Protein Complex; D044664:Porphyra; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013395:Sucrose / Q000494:pharmacology; D020524:Thylakoids / Q000378:metabolism; D014461:Ultracentrifugation
chemical_list: D045332:Photosystem II Protein Complex; D012967:Sodium Dodecyl Sulfate; D013395:Sucrose; D015086:2,6-Dichloroindophenol