铁氧还蛋白-NADP还原酶参与的循环电子传递  

The Involvement of Ferredoxin-NADP Reductase in the Photosynthetic Cyclic Electron Transport

作　　者：叶济宇[1] 王颖君[1] 

机构地区：[1]中国科学院上海植物生理研究所,200032

出　　处：《生物化学与生物物理学报》1997年第1期40-45,共6页

基　　金：国家自然科学基金(39370064)资助项目

摘　　要：铁氧还蛋白-NADP还原酶(FNR)的专一抑制剂——肝素在低浓度下可以强烈抑制菠菜类囊体中铁氧还蛋白(Fd)介导的NADP光还原,以及类囊体中Fd/NADP诱导的延迟发光增加。在厌氧和存在DCMU阻断来自光系统Ⅱ电子的情况下,可以观测到由9-氨基吖啶荧光猝灭所反映的由Fd介导的光系统Ⅰ循环电子传递。肝素强烈抑制这一反应。但对PMS催化的光系统Ⅰ循环电子传递影响较小。此外,利用观测Fd的光下还原表明,肝素不影响光系统Ⅰ到Fd的电子传递。以上结果表明肝素通过抑制FNR活力抑制循环电子传递,支持了FNR参与循环电子传递的设想。As an inhibitor of ferredoxin-NADP reductase (FNR), heparin strongly inhibited the Fd-mediated photoreduction of NADP in spinach thylakoids at very low concentration (micromole), and also inhibited the delayed light emission induced by Fd/NADP. Under anaerobic conditions, when DCMU was present to block electron transfer from photosystem Ⅱ, the Fd-mediated cyclic electron transport around photosystem Ⅰ as indicated by the quenching of 9-aminoacridine can be measured. Heparin could strongly inhibit this cycle, but had no significant effect on the PMS-mediated cyclic electron transport around photosystem Ⅰ. Heparin did not inhibit the electron transport from photosystem Ⅰ to ferredoxin, which was demonstrated by measuring the photoreduction of ferredoxin. The above results indicate that heparin inhibits ferredoxin-mediated cyclic electron transport by inhibiting the activity of FNR, and support the hypothesis of the involvement of FNR in cyclic electron transport.

关 键 词：光合作用 铁氧还原 NADP还原酶 循环电子传递 

分 类 号：Q945.11[生物学—植物学]