An improved method for isolation of photosystem II from marine alga Porphyra yezoensis Udea.
An improved method for isolation and characterization of photosystem (PS)II particles from thylakoid membranes of gametophytes of a marine alga Porphyra yezoensis Udea is reported. Thylakoid membranes were isolated using ultracentrifugation and differential speeds centrifugation and were further purified by the first sucrose density gradient centrifugation (SDGC). PSII particles with high 2, 6-dichloroindophenol (DCIP) photo-reduction activity were isolated by the second SDGC from the thylakoid membranes. Absorption and fluorescence spectra of the thylakoid membranes and PSII particles were recorded and their polypeptides composition was studied. Thylakoid membranes obtained by the above two methods showed similar spectral properties and polypeptides composition. PSII particles, in addition to common extrinsic proteins found in PSII of other plants, contained cyt c-550, a 20 kDa protein, along with two new proteins (14 kDa and 16 kDa).
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, The Chinese Academy of Sciences, Qingdao 266071, China.
Z Q
ZQ
Gao
G C
GC
Wang
C K
CK
Tseng
D015086:2,6-Dichloroindophenol / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D004591:Electrophoresis, Polyacrylamide Gel; D045332:Photosystem II Protein Complex / Q000302:isolation & purification* / Q000378:metabolism; D044664:Porphyra / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism; D020524:Thylakoids / Q000737:chemistry / Q000378:metabolism*; D014461:Ultracentrifugation
D045332:Photosystem II Protein Complex; D013395:Sucrose; D015086:2,6-Dichloroindophenol