Photoaffinity labeling of an herbicide receptor protein in chloroplast membranes

作者：Klaus Pfister, Katherine E. Steinback, Gary Gardner, Charles J. Arntzen · 发表于：Proceedings of the National Academy of Sciences · 年份：1981 · DOI：10.1073/pnas.78.2.981 · 被引用次数：324 · 研究领域：Photosynthetic Processes and Mechanisms、Pesticide and Herbicide Environmental Studies、Plant and animal studies

2-Azido-4-ethylamino-6-isopropylamino-s-triazine (azido-atrazine) inhibits photosynthetic electron transport at a site identical to that affected by atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine). The latter is a well-characterized inhibitor of photosystem II reactions. Azido-atrazine was used as a photoaffinity label to identify the herbicide receptor protein; UV irradiation of chloroplast thylakoids in the presence of azido[(14)C]atrazine resulted in the covalent attachment of radioactive inhibitor to thylakoid membranes isolated from pea seedlings and from a triazine-susceptible biotype of the weed Amaranthus hybridus. No covalent binding of azido-atrazine was observed for thylakoid membranes isolated from a naturally occurring triazine-resistant biotype of A. hybridus. Analysis of thylakoid polypeptides from both the susceptible and resistant A. hybridus biotypes by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, followed by fluorography to locate (14)C label, demonstrated specific association of the azido[(14)C]atrazine with polypeptides of the 34- to 32-kilodalton size class in susceptible but not in resistant membranes.