Photoaffinity labeling of the azidoatrazine receptor site in reaction centers of Rhodopseudomonas sphaeroides

FEBS Letters

Diner, Bruce A.¹  Vitry, Catherine de¹ 

[1] Institut de Biologie Physico-Chimique, 13, rue Pierre et Marie Curie, 75005 Paris, France

关键词: Bacterial reaction center;    Azido[14C]atrazine;    Herbicide inhibitor;    Photoaffinity labeling;    Rhodopseudomonas sphaeroides;    Ubiquinone;    azidoatrazine;    2-azido-4-ethylamino-6-isopropylamino-s-triazine;    BChl;    bacteriochlorophyll;    BPheo;    bacteriopheophytin;    LDAO;    lauryldimethylamine oxide;    SDS-PAGE;    polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate;    terbutryn;    2-methylthio-4-ethylamino-6-t-butylamino-s-triazine;    UQ-n;    ubiquinone (n corresponds to the number of isoprenoid units);   

DOI  :  10.1016/0014-5793(84)80151-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photoaffinity labeling of photosynthetic reaction centers of Rhodopseudomonas sphaeroides by the herbicide inhibitor, azido[¹⁴C]atrazine, occurs principally on the L-subunit. The specificity of labeling is greater at 77 than at 295 K. Kinetic studies of charge recombination in reaction centers indicate competition between azidoatrazine and ubiquinone-1 (Q-1) for binding to the reaction center. This competition occurs through the L-subunit binding site, as increasing concentrations of Q-1 decrease azido[¹⁴C]atrazine labeling of this site. It is proposed that the inhibitor binding site, predominantly on the L-subunit, and the secondary quinone binding site on the M-subunit, are adjacent so that there is partial overlap by one molecule of the domain occupied by the other.

【 授权许可】

Unknown