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.
Sun
Li
L
Department of Biochemistry, College of Chemical and Biological Science and Technology, Yantai University, Yantai 264005, PR China. sunlwang@public.ytptt.sd.cn
Wang
Shumei
S
Gong
Xieqin
X
Chen
Lixue
L
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