title: Phycoerythrins in phycobilisomes from the marine red alga Polysiphonia urceolata.
abstract: Phycoerythrins (PE) in phycobilisomes from Polysiphonia urceolata were studied in this research. Dissociative products of phycobilisomes were analyzed by sucrose density gradient centrifugation and native-PAGE. At least three types of PEs were found in the dissociative products of phycobilisomes. According to their molecular weights, absorption spectra and subunit components, they should be PE hexamer containing γ1 subunit, PE hexamer containing γ2 subunit and PE monomer containing no γ subunit. PEs bigger than hexmer were also found in the dissociative products of phycobilisomes in 200mM phosphate buffer when dissociated phycobilisomes were analyzed by sucrose density gradient centrifugation. PE trimers containing no γ subunits were also found in products of dissociated phycobilisomes in deionized water when dissociated phycobilisomes were analyzed by native-PAGE. This is the first time that pure PE hexamers containing γ2 subunits were isolated from P. urceolata. The PE monomers containing no γ subunits should come from PE trimers or hexamers containing no γ subunits in the "rod" of phycobilisomes. It can be concluded that there are three types of PEs in "rod" of phycobilisomes from P. urceolata: PE containing γ1 subunit, PE containing γ2 subunit and PE containing no γ subunit.
authors.affiliation: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, Shandong 266003, PR China; College of Life Sciences, Yantai University, Shandong 264005, PR China.
authors.forename: Mingri
authors.initials: M
authors.lastname: Zhao
authors.affiliation: College of Life Sciences, Yantai University, Shandong 264005, PR China. Electronic address: sunlwang@public.ytptt.sd.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.affiliation: Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, Shandong 266003, PR China.
authors.forename: Shichun
authors.initials: S
authors.lastname: Sun
authors.affiliation: College of Life Sciences, Yantai University, Shandong 264005, PR China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Gong
authors.affiliation: College of Life Sciences, Yantai University, Shandong 264005, PR China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Fu
authors.affiliation: College of Life Sciences, Yantai University, Shandong 264005, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
mesh_terms: D052979:Phycobiliproteins / Q000737:chemistry / Q000302:isolation & purification; D045524:Phycobilisomes / Q000737:chemistry; D010799:Phycoerythrin / Q000737:chemistry* / Q000302:isolation & purification; D000461:Rhodophyta / Q000737:chemistry*
chemical_list: D052979:Phycobiliproteins; D045524:Phycobilisomes; D010799:Phycoerythrin
keywords: Phycobilisome; Phycoerythrin; γ subunit