A rod-linker-contained R-phycoerythrin complex from the intact phycobilisome of the marine red alga Polysiphonia urceolata.
A linker-contained R-phycoerythrin (R-PE) complex was obtained by the Sephadex G-150 column chromatography from the Polysiphonia urceolata phycobilisome (PBS) that was dis-associated at 37 degrees C for 6 h in the dilute phosphate buffer (pH 7.0) with 5% (m/v) sodium dodecyl sulfate (SDS). The R-PE complex showed three absorption peaks at 498, 538 and 567 nm, and a fluorescence emission maximum at 578 nm. Polypeptide analysis of the complex by the 8-25% (m/v) gradient SDS-polyacrylamide gel electrophoresis demonstrated that it contained three red subunits, alpha(PE)(17.6),beta(PE)(19.2) and gamma(PE)(31.0), and a colorless 35.3 kDa rod-linker L(R)(35.3). Polypeptide proportion of the complex demonstrated that it was a hexamer in aggregate form gamma(PE)(31.6), (alpha(PE)(17.6),beta(PE)(19.2))(3)L(R)(35.3)(alpha(PE)(17.6),beta(PE)(19.2)(3)gamma(PE)(31.6) which is proposed to originate from a rod assembly of hexamer-linker-hexamer the substructure alpha(PE)(17.6),beta(PE)(19.2)(3) of which was decomposed off from the ends of the assembly during the PBS dissociation. The distinctive stability of the prepared hexamer is attributed to a large extent to the electrostatic interaction among its polypeptides, but not to the hydrophobic interaction.
Department of Biochemistry, College of Chemical and Biological Science and Technology, Yantai University, Yantai 264005, PR China. sunlwang@public.ytptt.sd.cn
Li
L
Sun
Shumei
S
Wang
Xieqin
X
Gong
Lixue
L
Chen
D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D057927:Hydrophobic and Hydrophilic Interactions; D008386:Marine Biology; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis / Q000737:chemistry; D045524:Phycobilisomes / Q000737:chemistry*; D010799:Phycoerythrin / Q000737:chemistry / Q000302:isolation & purification*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D000461:Rhodophyta / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D055672:Static Electricity
D001426:Bacterial Proteins; D010455:Peptides; D045524:Phycobilisomes; D010940:Plant Proteins; D010799:Phycoerythrin