The reaction order of the dissociation reaction of the B820 subunit of Rhodospirillum rubrum light‐harvesting I complex

FEBS Letters

Seguin, Jérôme¹  Arluison, Véronique¹  Robert, Bruno¹ 

[1] Section de Biophysique des Protéines et des Membranes, DBCM/CEA et URA CNRS 2096 C.E. Saclay, 91191 Gif/Yvette Cedex, France

关键词: Membrane protein;    Purple photosynthetic bacterium;    Bacteriochlorophyll;    Transmembrane α-helix;    Bchl;    bacteriochlorophyll;    B873;    B820 and B777;    dissociated forms of light-harvesting complex 1 absorbing at 873;    820 and 777 nm;    respectively;    CMC;    critical micellar concentration;    LH;    light-harvesting complex;    βOG;    n-octyl-β-D-glucopyranoside;   

DOI  :  10.1016/S0014-5793(02)02469-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied the equilibrium between the dissociated B777 form (absorbing at 777 nm) of the light-harvesting complex of Rhodospirillum rubrum and the oligomeric B820 form. Analysis of the reaction order for the B820 dissociation reaction to form B777 shows that this reaction depends on the concentration of octylglucoside detergent (n-octyl-β-D-glucopyranoside (βOG)) present in the sample. At low βOG concentrations (less than 1.2%) this reaction requires two components, presumably one α-B777 and one β-B777, implying that the B820 subunit is a dimer. At higher βOG concentrations this reaction requires four components, implying that B820 is a tetramer. These results partly explain the discrepancies in the literature about the stoichiometry of B820 and open an original way for studying protein–detergent interactions.

【 授权许可】

Unknown