Molecular Aspects of Herbicide Action on Protoporphyrinogen Oxidase

1993 ◽  
Vol 48 (3-4) ◽  
pp. 326-333 ◽  
Author(s):  
Beate Nicolaus ◽  
Gerhard Sandmann ◽  
Peter Böger
Keyword(s):  
Diphenyl Ether ◽  
Protoporphyrin Ix ◽  
Protoporphyrinogen Oxidase ◽  
Relative Specificity ◽  
Oxidase Inhibition ◽  
Dilution Experiments ◽  
Membrane Bound ◽  
The Common ◽  
Molecular Aspects ◽  
Derivatives Of

Abstract Protoporphyrinogen oxidase, the last enzyme of the common tetrapyrrole biosynthetic pathway, is inhibited by several peroxidizing compounds resulting in accumulation of photodynamic tetrapyrroles, mainly protoporphyrin IX. The inhibition characteristics of two chemi­cally unrelated compounds were studied using membrane bound protoporphyrinogen oxidase from corn etioplasts. As shown by Lineweaver-Burk-analysis, the inhibition of enzyme activity by the diphenyl ether oxyfluorfen and the cyclic imide MCI 15 are competitive with respect to the substrate. The competitive interaction of protoporphyrinogen and the two chemically un­related inhibitors indicate a relative specificity of the binding site. The reversibility of oxyfluorfen inhibition was evaluated by dilution experiments and was shown to be independent of the presence of DTT. The analysis of structure-activity-relationship on protoporphyrinogen oxidase inhibition was investigated with para-substituted derivatives of phenyl-3,4,5,6-tetrahydro-phthalimides. The results obtained by QSAR -calculation yielded a good correlation of the inhibitory activity determined by the lipophilicity of the para-substituent. These data point to one binding region of the inhibitors within a lipophilic environment associated with the active center of the enzyme.

scholarly journals Protoporphyrinogen oxidase as a molecular target for diphenyl ether herbicides

1989 ◽  
Vol 260 (1) ◽  
pp. 231-235 ◽  
Author(s):  
M Matringe ◽  
J M Camadro ◽  
P Labbe ◽  
R Scalla
Keyword(s):  
Zea Mays ◽  
Solanum Tuberosum ◽  
Diphenyl Ether ◽  
Protoporphyrin Ix ◽  
Molecular Target ◽  
Plant Tissues ◽  
Mitochondrial Membranes ◽  
Protoporphyrinogen Oxidase ◽  
Cellular Target

Diphenyl ether herbicides induce an accumulation of protoporphyrin IX in plant tissues. By analogy to human porphyria, the accumulation could be attributed to decreased (Mg or Fe)-chelatase or protoporphyrinogen oxidase activities. Possible effects of acifluorfen-methyl on these enzymes were investigated in isolated corn (maize, Zea mays) etioplasts, potato (Solanum tuberosum) and mouse mitochondria, and yeast mitochondrial membranes. Acifluorfen-methyl was strongly inhibitory to protoporphyrinogen oxidase activities whatever their origins [concn. causing 50% inhibition (IC50) = 4 nM for the corn etioplast enzyme]. By contrast, it was roughly 100,000 times less active on (Mg or Fe)-chelatase activities (IC50 = 80-100 microM). Our results lead us to propose protoporphyrinogen oxidase as a cellular target for diphenyl ether herbicides.

Isolation and Characterization of a Chlamydomonas reinhardtii Mutant Resistant to Photobleaching Herbicides

1993 ◽  
Vol 48 (3-4) ◽  
pp. 339-344 ◽  
Author(s):  
Hiromichi Oshio ◽  
Hideyuki Shibata ◽  
Nobuaki Mito ◽  
Masako Yamamoto ◽  
Elizabeth H. Harris ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Oxidase Activity ◽  
Higher Plants ◽  
Diphenyl Ether ◽  
Protoporphyrin Ix ◽  
Nuclear Genome ◽  
Photosynthetic Electron Transport ◽  
Wild Type ◽  
Protoporphyrinogen Oxidase ◽  
Isolation And Characterization

A group of highly active N -phenylimide photobleaching herbicides have been synthesized. These N -phenylimide herbicides as well as diphenyl ether herbicides induce protoporphyrin IX accumulation and inhibit protoporphyrinogen oxidase activity at extremely low concentrations in higher plants. The binding of a 14C -labeled N -phenylimide herbicide S-23121 [N-[4-chloro- 2-fluoro-5-[(1-m ethyl-2-propynyl)oxy]phenyl]-3,4,5,6-tetrahydrophthalimide] to the solubilized plastid fractions of greening corn seedlings is competed by the diphenyl ether herbicide acifluorfen-ethyl, but not by diuron, an inhibitor of photosynthetic electron transport. These results indicate a similar mode of action for both N -phenylimide and diphenyl ether herbicides.In order to investigate the mechanism of photobleaching herbicides at the molecular level, a strain of Chlamydomonas reinhardtii RS-3 resistant to N -phenylimide S-23142 [N -(4-chloro- 2-fluoro-5-propargyloxyphenyl)-3,4,5,6-tetrahydrophthalimide] was isolated by mutagenesis with N -m ethyl-N′-nitro-N -nitrosoguanidine. The 90% inhibition concentration of N -phenylimide S-23142 for growth of RS-3 was 100 times higher than that for wild type. Maximum accumulation of protoporphyrin IX was reached at 0.03 μᴍ of S-23142 for the wild type and 3 μᴍ for RS-3. RS-3 was resistant to oxadiazon, oxyfluorfen and acifluorfen-ethyl which had been shown to have the same mechanism of action as N -phenylimide herbicides, but not to paraquat, diuron or fluridone. Genetic analysis of RS-3 strain showed that the resistance results from a dominant mutation ( rs-3) in the nuclear genome. The magnesium protoporphyrin IX synthesizing activity from 5-am inolevulinic acid in chloroplast fragments isolated from RS-3 was less sensitive to S-23142 than that from wild type (CC-407). Protoporphyrinogen oxidase activity in Percoll™ -purified chloroplasts from RS-3 was also less sensitive to S-23142 than that from wild type. These results indicate that the resistance of RS-3 is specific for photobleaching herbicides, and that the mutation is related to protoporphyrinogen oxidase, the primary site of the photobleaching herbicide action.

scholarly journals Specific Binding of Protoporphyrin IX to a Membrane-Bound 63 Kilodalton Polypeptide in Cucumber Cotyledons Treated with Diphenyl Ether-Type Herbicides

1991 ◽  
Vol 96 (2) ◽  
pp. 432-437 ◽  
Author(s):  
Ryo Sato ◽  
Hiromichi Oshio ◽  
Hiroyuki Koike ◽  
Yorinao Inoue ◽  
Shigeo Yoshida ◽  
...  
Keyword(s):  
Specific Binding ◽  
Diphenyl Ether ◽  
Protoporphyrin Ix ◽  
Membrane Bound ◽  
Cucumber Cotyledons

scholarly journals Kinetic studies on protoporphyrinogen oxidase inhibition by diphenyl ether herbicides

1991 ◽  
Vol 277 (1) ◽  
pp. 17-21 ◽  
Author(s):  
J M Camadro ◽  
M Matringe ◽  
R Scalla ◽  
P Labbe
Keyword(s):  
Methyl Ester ◽  
Diphenyl Ether ◽  
Kinetic Studies ◽  
Inhibition Kinetics ◽  
Mitochondrial Membranes ◽  
Protoporphyrinogen Oxidase ◽  
Nitrobenzoic Acid ◽  
Diphenyl Ethers ◽  
Oxidase Inhibition ◽  
Kinetics Of

Diphenyl ethers (DPEs) and related herbicides are powerful inhibitors of protoporphyrinogen oxidase, an enzyme involved in the biosynthesis of haems and chlorophylls. The inhibition kinetics of protoporphyrinogen oxidase of various origins by four DPEs, (methyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen and its methyl ester, acifluorfen-methyl), methyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-chlorobenzoate (LS 820340) and methyl-5-[2-chloro-5-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (RH 5348), were studied. The inhibitions of the enzymes from maize (Zea mays) mitochondrial and etiochloroplastic membranes and mouse liver mitochondrial membranes were competitive with respect to the substrate, protoporphyrinogen IX, for all four molecules. The relative efficiencies of the inhibitors were: acifluorfen-methyl greater than LS 820340 much greater than RH 5348 greater than or equal to acifluorfen. The four molecules showed mixed-competitive type inhibition of the enzyme from yeast mitochondria where acifluorfen, a carboxylic acid, had the same inhibitory activity as its methyl ester, acifluorfen-methyl, and both were much greater than that of LS 820340 and RH 5348.

Effects of a diphenyl-ether herbicide, oxyfluorfen, on human BFU-E/CFU-E development and haemoglobin synthesis

1997 ◽  
Vol 16 (2) ◽  
pp. 115-122 ◽  
Author(s):  
B. Rio ◽  
D. Parent-Massin ◽  
S. Lautraite ◽  
H. Hoellinger
Keyword(s):  
Cellular Proliferation ◽  
Diphenyl Ether ◽  
Protoporphyrinogen Oxidase ◽  
Phytotoxic Activity ◽  
The Common ◽  
High Concentrations ◽  
Haemoglobin Content ◽  
Haemoglobin Synthesis ◽  
Chlorophyll Formation

The diphenyl-ether herbicides exert their phytotoxic activity by preventing chlorophyll formation in plants as a result of inhibition of protoporphyrinogen oxidase. This enzyme is the last step of the common pathway for chlorophyll and haem biosynthesis. The aim of this work is to determine whether herbicide inhibitors of plant protoporphyrinogen oxidase could act on the human protoporphyrinogen oxidase involved in haemoglobin synthesis and cause heamatologic diseases. Human erythroblastic progenitors (BFU-E/CFU-E: Burst Forming Unit-Erythroid and Colony Forming Unit-Ery throid) were exposed to oxyfluorfen, a diphenyl-ether herbicide in the presence of erythropoietin, and the haematoxicity evaluated in vitro by scoring the develop ment of BFU-E/CFU-E colonies after 7 and 14 days of culture. The toxic effect on differentiation has been evaluated using four criteria: morphology, total protein, total porphyrin, and haemoglobin content. The study of BFU-E/CFU-E proliferation and differentia tion showed a cytotoxic effect of oxyfluorfen only at very high concentrations. In contrast, haemoglobin synthesis can be inhibited by concentration of oxyfluorfen (10-4 M) that have no adverse effect on cellular proliferation.

scholarly journals PPO-Inhibiting Herbicides and Structurally Relevant Schiff Bases: Evaluation of Inhibitory Activities against Human Protoporphyrinogen Oxidase

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 383
Author(s):  
Milan Jakubek ◽  
Michal Masařík ◽  
Tomáš Bříza ◽  
Robert Kaplánek ◽  
Kateřina Veselá ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Schiff Bases ◽  
Anticancer Agents ◽  
Protoporphyrin Ix ◽  
Docking Study ◽  
Structural Motif ◽  
Protoporphyrinogen Oxidase ◽  
Ic50 Values ◽  
Inhibitory Activities ◽  
Potential Inhibitors

The study of human protoporphyrinogen oxidase (hPPO) inhibition can contribute significantly to a better understanding of some pathogeneses (e.g., porphyria, herbicide exposure) and the development of anticancer agents. Therefore, we prepared new potential inhibitors with Schiff base structural motifs (2-hydroxybenzaldehyde-based Schiff bases 9–13 and chromanone derivatives 17–19) as structurally relevant to PPO herbicides. The inhibitory activities (represented by the half maximal inhibitory concentration (IC50) values) and enzymatic interactions (represented by the hPPO melting temperatures) of these synthetic compounds and commercial PPO herbicides used against hPPO were studied by a protoporphyrin IX fluorescence assay. In the case of PPO herbicides, significant hPPO inhibition and changes in melting temperature were observed for oxyfluorten, oxadiazon, lactofen, butafenacil, saflufenacil, oxadiargyl, chlornitrofen, and especially fomesafen. Nevertheless, the prepared compounds did not display significant inhibitory activity or changes in the hPPO melting temperature. However, a designed model of hPPO inhibitors based on the determined IC50 values and a docking study (by using AutoDock) found important parts of the herbicide structural motif for hPPO inhibition. This model could be used to better predict PPO herbicidal toxicity and improve the design of synthetic inhibitors.

scholarly journals Anthroponyms of Jewish Women in the 16th Century Grand Duchy of Lithuania

2012 ◽  
Vol 21 (26) ◽  
pp. 200-207
Author(s):  
Jūratė Čirūnaitė
Keyword(s):  
Average Length ◽  
Family Members ◽  
16Th Century ◽  
Canonical Forms ◽  
Family Status ◽  
Social Origin ◽  
Jewish Women ◽  
The Common ◽  
Grand Duchy Of Lithuania ◽  
Derivatives Of

The most popular names among Jewish women in 16th century Lithuania were Simcha, Marjam, Anna, Debora. The names were most frequently recorded as diminutives (63.3%), with only 36.4% appearing in canonical forms. The smallest group comprises names formed using only anthroponyms that were derived from those of (male) family members (29.6%). 35.2% of the namings are recorded as mixed type. The same number of women are recorded using only names in the documents.Personal names are included in 70.4% of recorded women’s namings. Andronyms (anthroponyms formed from the spouse’s name) were found in 64.8% of all the records. 9.3% of women’s namings include anthroponyms formed using the spouse’s patronymic. Only 1.9% of namings had a female patronymic (the derivative of the suffix -owna/-ewna).One-member female namings prevail (59.3%). Two-member namings comprise 33.3%. Three members are found in 5.6% of the namings, while four-membered ones comprise 1.9%. The average length of the namings is 1.5 times that of the anthroponyms.Common words explaining anthroponyms were found in 68.5% of the namings. Common words related to religion prevail (51.4%). 29.7% of the common words characterize relationships or family status, and only 10.8% describe occupation, post or trade (vocation). Common words describing descent (social origin) comprise only 8.1% of all the women’s namings.Namings consisting only of anthroponyms of family members can be subdivided into the following subgroups: 1) derivatives of the suffix -owaja/-ewaja; 2) derivatives of the suffix ‑owaja/-ewaja; 3) derivatives of the suffix -owaja/-ewaja + the genitive of a male patronymic; 4) derivatives of the suffix -owaja/-ewaja + a male patronymic + the genitive of a male patronymic. Namings without anthroponyms consisting of family members included names and names with common words. Mixed namings consisted of: 1) a name + a derivative of the suffix -owaja/-ewaja; 2) a derivative of the suffix -owaja/-ewaja + the genitive of a male patronymic + a name; 3) a derivative of the suffix -owaja/-ewaja + the genitive of a male patronymic + a name + a female patronymic.The most popular type of naming is a recorded name.

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