5-O-BETA-D-GALACTOPYRANOSYL-7-METHOXY-3',4'-DIHYDROXY-4-PHENYLCOUMARIN, AN INHIBITOR OF PHOTOPHOSPHORYLATION IN SPINACH-CHLOROPLASTS

被引：18

作者：

CALERA, MR ^{[1
]}

MATA, R ^{[1
]}

ANAYA, AL ^{[1
]}

LOTINAHENNSEN, B ^{[1
]}

机构：

[1] NATL AUTONOMOUS UNIV MEXICO, INST FISIOL CELULAR, MEXICO CITY 04510, DF, MEXICO

来源：

PHOTOSYNTHESIS RESEARCH | 1995年 / 45卷 / 02期

关键词：

PHENYLCOUMARIN; ENERGY-TRANSFER INHIBITOR; PHOTOSYNTHESIS; CF0-H+-CHANNEL INHIBITOR; RUBIACEAE; EXOSTEMA CARIBAEUM;

D O I：

10.1007/BF00032581

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

5-O-beta-D-galactopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin isolated from Exostema caribaeum (Rubiaceae) has been found to act as an energy-transfer inhibitor in spinach chloroplasts. ATP synthesis and phosphorylating (coupled) electron flow were inhibited by 89 and 72%, respectively, at a concentration of 400 mu M. H+-uptake, basal and uncoupled electron transport were not affected by the coumarin. The light-activated Mg+2-ATPase activity from bound membrane thylakoid chloroplasts was slightly inhibited by the coumarin. Also, the heat-activated Ca+2-ATPase activity of the isolated coupling factor protein was insensitive to this compound. In chloroplasts partially stripped of coupling factor 1 by an EDTA treatment, the coumarin showed a restoration of the proton uptake process. These results suggest that the 4-phenylcoumarin under investigation inhibited phosphorylation in chloroplasts by specifically blocking the transport of protons through a membrane-bound component or a carrier channel (CF0) located in a hydrophobic region at or near the functional binding site for the coupling factor 1.

引用

页码：105 / 110

页数：6