http://www.abbs.info      E-mail: [email protected]

ISSN 1672-9145                                                 Acta Biochim Biophys Sin 2004, 36(11): 780–785                                                  CN 31-1940/Q

Isolation and Characterization of Photosystem II of Porphyra yezoensis Ueda

Zheng-Quan GAO1,2, Guang-Ce WANG1*, and Cheng-Kui TSENG1

 

1Key Laboratory of Experimental Marine Biology, Institute of Oceanology, the Chinese Academy of Sciences, Qingdao 266071, China;

2Graduate school, the Chinese Academy of Sciences, Beijing 100039, China

 

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.

 

Key words        red algae; Porphyra yezoensis Ueda; photosystem II; polypeptide composition; extrinsic protein

 

 

-----------------

Received: July 20, 2004        Accepted: October 8, 2004

This work was supported by the grants from the National Natural Science Foundation of China (No. 30170499, No. 40476059, No. 30250003, and No. 39890390) and the Project of Scientific Innovation of Institute of Oceanology, the Chinese academy of Sciences (2002-2005)

*Corresponding author: Tel, 86-0532-2898575; Fax, 86-0532-2880645; E-mail, [email protected]