Roshchina V V, Solomatkin V P, Mutuskin A A
Biokhimiia. 1982 Jun;47(6):937-44.
The effects of polyene antibiotic amphotericin B and the organophosphorus insecticide chlorophos (trichlorofon) on the electron transport in isolated pea chloroplasts were compared; both compounds were found to inhibit the electron transport. The concentration dependence of the inhibitory effects on the photoreactions in chloroplasts was established. Affer washing of the chloroplasts from amphotericin B admixtures the photoreduction of NADP+ was decreased by 50%, the photooxidation of cytochrome f in situ was affected comparatively little, while the photoreduction of plastocyanin in situ was decreased by 60%. The supernatant after amphotericin B washing contained plastocyanin. An addition of chlorophos to the medium caused a 70% inhibition of NADP+ photoreduction and a 40% inhibition of cytochrome f photooxidation and of plastocyanin photoreduction. It was assumed that the active site of amphotericin B lies in the plastocyanin region, that of chlorophos--at the site of NADP+ photoreduction in photosystem I. Experiments with isolated pea plastocyanin and ferredoxin and cytochrome C553 of Chlorella demonstrated that neither of the inhibitors interacts with the prosthetic groups or with he protein part of these electron carriers. Presumably the mechanism of action of amphotericin B and chlorophos on the photosynthetic electron transport consists in a destruction of chloroplast membrane structures. Using membrane-active inhibitors, the alternative pathways of electron transfer through cytochrome f and plastocyanin were established.
比较了多烯抗生素两性霉素B和有机磷杀虫剂毒死蜱（敌百虫）对分离的豌豆叶绿体中电子传递的影响；发现这两种化合物均能抑制电子传递。确定了对叶绿体中光反应抑制作用的浓度依赖性。用两性霉素B混合物洗涤叶绿体后，NADP⁺的光还原降低了50%，细胞色素f的原位光氧化受影响相对较小，而质体蓝素的原位光还原降低了60%。两性霉素B洗涤后的上清液中含有质体蓝素。向培养基中添加毒死蜱导致NADP⁺光还原抑制70%，细胞色素f光氧化和质体蓝素光还原抑制40%。据推测，两性霉素B的活性位点位于质体蓝素区域，毒死蜱的活性位点位于光系统I中NADP⁺光还原位点。用分离的豌豆质体蓝素、铁氧化还原蛋白和小球藻的细胞色素C553进行的实验表明，这两种抑制剂均不与这些电子载体的辅基或蛋白质部分相互作用。推测两性霉素B和毒死蜱对光合电子传递的作用机制在于破坏叶绿体膜结构。使用膜活性抑制剂，确定了通过细胞色素f和质体蓝素的电子传递替代途径。
